(Free Copy) The Performance Digest - Issue 48 October 2020

THE

October 2020| Issue #48

PERFORMANCE DIGEST

A monthly summary of the latest sports performance research

© Copyright - Science for Sport Ltd 2016-2020. All Rights Reserved.

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Page Number

Section

Link to Abstract Review Title

Study Details

Practical Takeaways from study

Related links to learn more about the topic

Reviewers comments on the study

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Contents Click a topic to jump straight there

06 Reviewers

The brains behind the brilliance

07 Catapult Corner

A deep-dive into the latest sports technology

09 The Science of Coaching The doctors diagnosis

10 Strength & Conditioning Performance-enhancing science

14 Technology & Monitoring The tech revolution

18 Fatigue & Recovery You can’t adapt without recovery

22 Youth Development Their future is in our hands

26 Nutrition

You are what you eat

30 Injury Prevention & Rehab Minimising injury and maximising recovery

Š Copyright - Science for Sport Ltd 2016-2020. All Rights Reserved.

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06

Research Reviewers Dr. Will Vickery PhD

Owen Walker MSc CSCS

Chief Editor

Fatigue & Recovery

Will is a Lecturer of Sport Coaching at Deakin University, Australia. Prior to

Owen is the Founder & Director of Science for Sport. He was formerly

this he has worked with Cricket NSW and Cricket Australia in an array of

the Head of Academy Sports Science and Strength & Conditioning at

roles ranging from a sport scientist, development coach and a strength and conditioning coach. He completed his PhD at the University of Newcastle, Australia within the area of practice design.

Adam Kerr MSc ASCC The Science of Coaching

Cardiff City Football Club, and an interim Sports Scientist for the Welsh FA.

Tom Green MSc UKAD Advisor Youth Development

Adam is the Academy Performance Support Manager at Leeds United FC, and

Tom is the Head of Athletic Development at St Peters RC High School.

has previously worked at Middlesbrough FC, Arsenal FC, Scunthorpe United FC

He holds a Masters in S&C and has previously worked with West

and the Professional Golfers Association. He holds a Masters degree in Sport Science from Sheffield Hallam University and is an accredited strength and conditioning coach with the UKSCA.

James de Lacey MSc

Strength & Conditioning

James is currently the Head Strength & Conditioning Coach for the Romanian Rugby Union. He has previously worked in America's professional rugby competition Major League Rugby with Austin Elite and the NZ Women’s National

Bromwich Albion FC, Gloucester Rugby club, and Great Britain Equine.

Tom is our youth research reviewer at Science for Sport.

Dr. James Morehen PhD

Nutrition

James is a Performance Nutritionist for the English Football Association and works alongside the England national teams (men's

Rugby League Team. He is a published author and has completed a MSc in Sport

and women's). He is also a SENr registered performance nutritionist

& Exercise Science from AUT, Auckland, NZ.

and holds a PhD from Liverpool John Moores University.

Cody Roberts MSE Technology & Monitoring

Cody is a strength and conditioning coach and adjunct lecturer at the University of Iowa. He has an MSE in Exercise Science from the University of Kansas and also holds a CSCS from the NSCA.

Š Copyright - Science for Sport Ltd 2016-2020. All Rights Reserved.

Dr. Jordan August DPT, CSFC, SFMA, FMS Injury Prevention & Rehab

Jordan is a Physical Therapist and Strength Coach who currently practices in a Sports & Orthopedic clinic in Bergen County, New Jersey. He is passionate about educating athletes on ways to optimize performance while decreasing the risk of injury.

SAFELY RETURNING ATHLETES TO PLAY, TRAINING, AND COMPETITION Return to play from injury is a

Exercise must be prescribed with

injuries at multiple levels. Under

lengthy and complex process

an emphasis on the fundamental

most circumstances, individual

for both the athlete and the

components of the exercise

providers should not be expected

performance staff. The injured

prescription, which progressively

to possess the knowledge

athlete works with a range of

incorporates activities and skills

and training needed to ensure

practitioners, from physicians

displayed in sport.

complete recovery for athletes

to athletic trainers to physical

When athletes resume team-

through all stages of the return-

therapists to strength and

based strength and conditioning

to-play process.

activities, emphasis should be

A thorough examination of the

Once moved through the

on generic movements and

injured athlete and a careful

medical-driven phase of the

sport-specific movements that

evaluation of all findings

rehabilitation process, the

makes up the complete strength

are essential to an accurate

athlete generally returns to

training program for an athlete.

diagnosis, from a structural and

strength and conditioning

Athletes generally benefit

biomechanical perspective. A

conditioning specialists.

programs to resume sportspecific activities in preparation for return to play.

THIS TRANSITION IS IMPORTANT FOR MANY REASONS: The athlete may have recovered in medical terms (ie, improvements in flexibility, range of motion, functional strength, pain, neuromuscular control, inflammation), preparation for competition requires the restoration of strength, power, speed, agility, and endurance at levels exhibited in sport.

Sport-specific training may be beyond what those attending to the athlete’s medical needs are qualified or prepared to provide.

Returning from injury requires additional athlete investment to regain competitive ability.

from input from all providers throughout the process of returning to play, but often pay the price for poorly-coordinated return-to-play.

Communication is a vital factor through the entire process, with a lack of communication between performance and medical practitioners seen to negatively impact an athlete’s safe return to play and increase the risk of new injuries. In addition to the physical progression of an athlete’s return to competition, practitioners must also consider the psychological consequences of injuries.

Practitioners must work to ensure that care can be provided at all points of the rehabilitation process, especially when funding dictates the need to hire personnel capable of addressing

clear understanding of the injury and of the interventions from each practitioner is vital to an efficient and successful return to play. Each practitioner must make clear the purpose of each treatment and the restrictions from specific activities during

the rehabilitation process while

the status of injuries. Regardless

conceal worsening conditions

providing supervision at points

of an athlete’s apparent level of

or delay return to play because

of progression and when new

recovery, constant feedback from

of a lack of confidence or

activities are initiated.

the athlete is needed to gauge

disagreement in the perceived

INITIAL INJURY PROCESS

PRACTITIONER

ROLE

Physicians

Examine, re-evaluate, diagnose, surgical correction

Physical Therapists Athletic Trainers Physicians

Manage pain, limit swelling, protect injured tissues

REHABILITATION

Athletic Trainers Physical Therapists

Restore motion, neuromuscular control of individual muscle groups

END-STAGE REHABILITATION

Athletic Trainers Physical Therapists Strength & Conditioning Specialists

Restore balance, reflex control, strength, endurance

GENERIC-SPECIFIC DEVELOPMENT

Strength & Conditioning Specialists

Restore most basic physical performance functions

SPORT-SPECIFIC DEVELOPMENT

Sports Coaches Strength & Conditioning Specialists

Restore competitive performance functions

MEDICAL TREATMENT

and adjust exercise prescriptions.

severity of the injury. Such

The athlete’s perception during

monitoring is the responsibility of

periods of recovery from injury

all involved until the athlete has

can provide valuable direction in

been provided medical clearance

collaborate, and administer

the decision-making process.

to discontinue all rehabilitative

treatments. Furthermore,

In addition, athletes must be

care and return to unrestricted

clinicians must inform strength

regularly assessed to ensure

and conditioning specialists on

that they are not attempting to

An awareness of the exercise prescription on any given day will better enable rehabilitation practitioners to anticipate,

sports participation.

D E C I S I O N S F O R D E S I G N I N G A R E S I S TA N C E T R A I N I N G P R O G R A M TOPIC

QUESTION

CHOICE OF EXERCISE

What exercises will be used in the program?

ORDER OF EXERCISE

What is the sequence of the exercises chosen?

INTENSITY

What will be the intensity of resistance loading of the exercises used?

NUMBER OF SETS

How many sets will be used for a given exercise?

REST PERIOD LENGTHS

How much rest will be utilised between sets and exercises?

09

The Science of

Improving athlete-perceived coaching competency Can a coaching effectiveness intervention improve the athlete’s perception of coach competence?

INTRODUCTION

WHAT THEY FOUND

WHAT THIS MEANS

An athlete’s enjoyment, satisfaction with their coach, and perceptions of a coach’s competency are greatly affected by the coach’s interpersonal style (see HERE). As such, strategies to develop these skills in coaches are viewed as very important. These strategies and programs are generally formed from theoretical frameworks such as; Self Determination Theory (SDT) (see HERE), and the Achievement Goal Theory (AGT) (see HERE) to Coach Effectiveness Training (CET) (see HERE).

Baseline and post-programme data were collected from eight soccer coaches and 117 young male soccer players who were split into two groups, an experimental group, and a control group. Athletes' perceived coaching competency data was collected using the Sport Athletes’ Perceptions of Coaching Competency Scale II-High School Teams (APCCS II-HST), players perceptions of their satisfaction with the coach using the Satisfaction with the Head Coach Scale (SHC-S), and enjoyment levels using an adaptation of the Sport Satisfaction Instrument.

The findings from the study highlight the struggles for coaches over the course of a season, as it has been previously found that athlete-perceived coaching competency actually decreases throughout the season (see HERE), so any improvements in the perceived coaching competency may be reflected in pre- and postprogramme data being the same, which would still be a positive finding.

Despite most SDT-based interventions being aimed at improving an athlete’s performance, understanding the athlete’s perception of their coaches has not previously been considered. As studies show, positive perception of a coach leads to an athlete becoming more engaged and autonomous (see HERE), however, it would help to understand what interventions would improve the coach’s competency. This is also the same for CET, where a high athlete-perceived coaching competency has been associated with higher levels of satisfaction with the coach, greater levels of effort, commitment, enjoyment, and cohesion from the athletes (see HERE). Yet, there is a lack of understanding as to what can actually improve the coaches competency. Therefore, the aim of this study was to analyse the effect of a coaching competency intervention programme.

The experimental group coaches had an intervention training programme delivered over four days during the season and consisted of 12h worth of contextualisation, theoretical frameworks, and methodological and motivational strategies, delivered by university staff who were also soccer coaches (UEFA PRO license). The control group carried out their normal training practices without any additional input.

The results highlighted that the players within the experimental group perceived their coach to have improved game strategy, technique, and characterbuilding competencies compared to the players' perceptions of the coaches in the control group, which helps a player decide to devote more time to performing an activity, developing more self-determined motivation and greater adherence to its practice, which subsequently helps with performance.

As most of the athlete-perceived coaching competency measures were either maintained or increased for those in the experimental group (compared to the control group), a coach intervention programme such as this, along with education on the many different factors of a successful coach-athlete relationship, could be seen as a key part of any club or governing body. It is also important to highlight that previous research has shown that the relationships between coaches and athletes decrease over the course of a season due to many different factors (e.g. match results, selection), and therefore, success in the coachathlete relationship dynamic might actually be measured best by any maintenance in the levels of respect and understanding with each other.

One other positive from the intervention was the impact on players’ enjoyment. Despite players not perceiving their coaches as more competent at motivating them, it was found that the coaches used their knowledge from the intervention programme to alter their training sessions, after the intervention. Athletes considered their training after the intervention to be more enjoyable, and therefore may help the athlete in deciding to devote time to performing an activity, developing more self-determined motivation, and greater adherence to its practice.

Practical Takeaways 



Coaches should educate themselves on the different motivational theories around coach-athlete relationships, as improving this helps gain trust and buy-in from players, which can then help performances and prevent player dropout.



Coaches need to understand that the coach-athlete relationship will depend on a number of key factors throughout a season (e.g. match result, selection, club pressures), and therefore the coach may need to be very individualised and situation-specific in their approach to managing the performance levels of their players.

Coaches should utilise coaching styles individual to an athlete’s personality and personal situation (e.g. the context) to enhance player enjoyment, which can then improve adherence to a coaching programme.

© Copyright - Science for Sport Ltd 2016-2019. All Rights Reserved.

Adam Kerr Adam is the Head of Physical Performance for Scunthorpe United FC and has previously worked at Middlesbrough FC, Arsenal FC and the Professional Golfers Association.

[Abstract]

COACHING

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Strength & Conditioning

10

Strength & Conditioning This month’s top research in strength & conditioning.

SHOULD WE INDIVIDUALISE PROGRAMMES

BASED ON FORCE-VELOCITY PROFILING TO ENHANCE PERFORMANCE? Simpson, A. et al. (2020) Journal of Sports Sciences.

HOW SHOULD YOU COMBINE RESISTANCE TRAINING AND AEROBIC CONDITIONING TO MINIMISE THE INTERFERENCE EFFECT? Sousa, A. C. et al. (2020) The Journal of Strength and Conditioning Research.

SHOULD YOU ALWAYS PERFORM JUMP AND PLYOMETRIC TRAINING ON THE SAME SURFACE FOR MAXIMISING GAINS? Ramirez-Campillo, R. et al. (2020) The Journal of Strength and Conditioning Research.

© Copyright - Science for Sport Ltd 2016-2020. All Rights Reserved.

Strength & Conditioning

11

[Abstract]

Should we individualise programmes based on force-velocity profiling to enhance performance?

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

The development of power requires the selection of loads across the force-velocity (F-V) spectrum. Training at an optimal power load may improve maximal power in a given exercise, but it may not be the most efficient way to improve power during sport-based movements. Thus, assessing an athlete's F-V profile may provide better information to prescribe the most effective loading to optimise the F-V profile and maximise power output during unloaded jumping.

Twenty-nine professional rugby league players (age = 24 ± 3 yr) were split into an optimised training group (OP), or a nonoptimised control group (CON) based on pre-intervention testing. Pre-testing consisted of 10- and 20m sprints, 3RM back squat, and squat jump (SJ) with five separate loads (0-, 20-, 40-, 60-, and 80% of body mass) to determine the F-V profile and FV imbalance (FVimb). The training protocol for each group included:



There is little evidence on the impact of this approach though, especially in highly trained professional athletes. Therefore, the authors of this study assessed the effectiveness of optimised training that was based on individual F-V profiles on sport-relevant tasks.

maximum force (F0) and higher values than CON, while the CON group showed enhanced theoretical maximum velocity (V0) with higher values than OP following the intervention.



CON

The OP group showed greater shifts towards an optimal F-V profile, greater 3RM back squat, peak power, and greater SJ height, compared with CON after the intervention.

OP 8-week training programme adjusted for their FVimb.

Participants were placed in low-force deficit (60-90% FVimb), high-force deficit (<60% FVimb), low-velocity deficit (>110-140% FVimb), and high-velocity deficit (>140% FVimb) groups based on pre-testing.

The OP group showed improvement in theoretical



No differences were found in 10m and 20m sprint from before to after the intervention for both groups, however, both slightly improved.



There were no differences in RPE between the groups.

Standard 8-week strength-power programme. Participants were placed in low-force deficit (60-90% FVimb) and highforce deficit players (<60% FVimb) groups based on pretesting.

All programmes were matched for volume. Ratings of perceived exertion (RPE) were collected for breathlessness and leg fatigue. All on-field training was maintained throughout the training protocol period.

Practical Takeaways While taking an individual programming approach based on vertical F-V profiling is a great way of improving strength, peak power, and jump height, placing all your eggs into this basket likely won’t give you the full performance picture. Collecting data from a vertical and horizontal F-V profile may allow you as the coach to nail down the exact programming prescription your player needs to maximise take-off velocity in the horizontal and vertical direction. Here are some best practices when performing F-V profiling vertically and horizontally: Vertical F-V Profiling



Pre-test measurements of the greater trochanter to the end of pointed toes, the greater trochanter to the floor in 90° squat position, and the height of the acromioclavicular shoulder joint to the floor. These help to easily standardise the depth of the jump and remove any potential countermovement.



Group your athletes into similar shoulder heights so you can easily get a group of 4-5 going at once.



Put your iPad or iPhone into slow-motion. When recording with older models, you may need to allow for 2-3 sec of recording time before the athlete jumps and the same after they land, otherwise you'll miss the slow motion.



Instead of using the percentage of body mass for loading, standardise the load for efficiency. For example, for males = 0-, 20-, 40-, 60 kg (70/80 kg if you have time) and for females = 0-, 15-, 30-, 45 kg (55/60 kg if you have time).

Horizontal F-V Profiling 

As with vertical profiling, filming your whole squad in slow-motion will save you a lot of time. It generally takes me up to 20 min to get through approximately thirty players for three sprints each.



Make sure they start in a 3-point stance so you have a reference for when to start the analysis which will be when the hand leaves the ground.



Add an extra marker at the end so players don’t slow down once they’ve passed the 6th pole as parallax error will have you still needing the player at full speed slightly past the 6th pole.

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Then check these out...

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James’ Comments “In my opinion, this is the way of the future when it comes to programming and periodisation.

Traditional periodisation doesn’t take into account these individual differences regarding F-V profiles. You may want to start emphasising maximal strength, before gradually moving towards power-based training as the season nears.

However, if you have players that are already force dominant, perhaps their time is better spent focusing more time on the velocity side of the spectrum earlier in the pre-season, as opposed to the horizontal. As you keep testing, you can keep refining the programme and moving players between groups of high- and low-force and velocity.”

Strength & Conditioning

12

[Abstract]

How should you combine resistance training and aerobic conditioning to minimise the interference effect?

OBJECTIVE

WHAT THEY DID

Concurrent training (CT) is a training method that combines resistance and aerobic training within the same training session. However, CT has been shown to mitigate the training response of either type of training (i.e. resistance and aerobic) known as the interference effect (see HERE). One of the major problems with CT (instead of focusing on either resistance or aerobic) is the training intensity that can be achieved, and only a few studies have investigated this during CT. Further, the effects of CT following detraining periods during a playing season are poorly understood.

Thirty-six physically active men (age = 18-25 yr) were assessed before (PRE) and after (POST) the 8-week training intervention, as well as after the 4-week detraining period (POSTD). Testing consisted of 10m and 20m sprints, a 20m multi-stage fitness test to determine maximal aerobic speed (MAS) and VO2max, vertical jump on a contact mat, and a Smith machine squat estimated 1RM using a linear position transducer.

Therefore, this study aimed to investigate the effect of three CT programmes at different aerobic training intensities and analyse the effects of a 4-week detraining period.



⇒

Low-intensity (LIG; 80% MAS).

⇒

Moderate-intensity (MIG; 90% MAS).

⇒

High-intensity (HIG; 100% MAS).

⇒

Control group (CON; who didn’t train).

Practical Takeaways 

Based on the results of this study on physically active men, CT using lower intensity aerobic conditioning can be a way to develop multiple fitness qualities at the same time without much of an interference-effect.



Generally, ’untrained’ individuals respond well to any stimulus, however, in this group, higher intensity aerobic conditioning didn’t provide the same improvements as lower intensity running. Therefore, in a general population setting, lower intensity aerobic exercise following a resistance training session is likely a better option and only takes approximately 16-20 min. Here is how you could implement the aerobic conditioning after resistance training: 2:1 work:rest ratio @80% MAS work:50-60% MAS active rest. 

Week 1: 6 x 60 sec/30 sec @ 80/50% MAS



Week 2: 9 x 60 sec/30 sec @ 80/50% MAS



Week 3: 12 x 60 sec/30 sec @ 80/50% MAS



Week 4: 4 x 90 sec/45 sec @ 80%/50% MAS

OR 

Week 1: 9 x 60 sec/30 sec @ 80/50% MAS



Week 2: 12 x 60 sec/30 sec @ 80/50% MAS



Week 3: 9 x 60 sec/30 sec @ 80/60% MAS



Week 4: 12 x 60 sec/30 sec @ 80/60% MAS

Progression can simply be made by either increasing duration of the working effort, increasing the number of reps, or increasing the intensity of the active rest. Using these variables, you can still progress without exceeding your session time limit.

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All experimental groups improved from PRE to POST in all variables except the high-intensity group for 10m sprint, and the control group showed no changes for any variable.



In the experimental groups, greater improvements

were found in estimated 1RM in the low-intensity group compared with moderate and high-intensity groups.

There was also a tendency for greater gains in vertical jump, and 10m and 20m sprint in the low-intensity group compared with the moderate and high-intensity groups.

Participants were randomly assigned to one of four groups:

Participants trained twice a week for 8 weeks, completing a resistance training session of Smith machine squats @ 70-85% 1RM, jumps, and sprints. Aerobic training was performed 20 min following this at the prescribed intensity based on their group for 16-20 min. This consisted of performing the 20m shuttle run until reaching 80% (LIG), 90% (MIG), or 100% (HIG) of MAS. No training was performed during the detraining period.



WHAT THEY FOUND



At POSTD, the moderate-intensity group showed performance decrements in all variables, whereas the low-intensity group showed decreased performance in vertical jump and estimated 1RM, whilst the highintensity group showed decreased performance in 10m sprint, estimated 1RM, and VO2max.

James’ Comments “What would be interesting is seeing how these methods would translate in a more professional/high-performance athlete environment. With high training ages and better overall physical conditioning, the interference effect may play a greater role in highly trained athletes.

Where possible, I would advise keeping conflicting physical qualities as far apart as possible when training (e.g. performing resistance training in the morning and aerobic conditioning in the afternoon), however, this is not always possible. So, when you are pressed for time, the rule of thumb is to perform resistance training before aerobic conditioning.”

Strength & Conditioning

13

[Abstract]

Should you always perform jump and plyometric training on the same surface for maximising gains?

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Several factors can be considered when implementing plyometric jump training (PJT), such as direction, volume, intensity, and training surface. Unfortunately, very few studies have investigated the use of different surfaces for PJT. A recent study reported that 64% of PJT studies didn't even report information on the training surface (see HERE).

Twenty-three youth male regional level soccer players (age = 11-14 yr) were randomly assigned to either a combined surfaces PJT group (PJTc), a single surface PJT group (PJTs), or an active control group (CON). Before and after the 8week intervention, participants performed a countermovement jump (CMJ), broad jump (BJ), drop jump from a 20 cm box (DJ), maximal kicking velocity, 30m sprint, and the Meylan change of direction test (COD) (see HERE).



Both the PJTs and PJTc groups improved CMJ, BJ, DJ, 30m sprint, and COD, but only the PJTc group improved maximal kicking velocity.



PJTc showed greater improvement in CMJ (10.5% vs. 5.8%), BJ (13.1% vs. 8.6%) DJ (23.8% vs. 9.3%), maximal kicking velocity (13.5% vs.

8.5%), 30m sprint (9.1% vs. 5.8%), and COD (9.0% vs. 5.2%) compared to PJTs, respectively.

Those in the PJTc group were required to perform jumps equally distributed over six different surfaces: grass, dirt, sand, wood, gym mat, and tartan track, whereas the PJTs group performed all jumps on grass, both groups completing these jumps immediately after their on-field warm-up. The CON group followed regular soccer training over the 8-week period.



No changes were observed for CON for any variable.

The type of surface may induce different adaptations to performance, for example, soft surfaces may benefit an athlete’s squat jump performance, while hard surfaces may actually benefit countermovement jump due to the different neuromuscular and musculartendinous properties.

Therefore, this study compared the effects of PJT on different surfaces compared to PJT on a single surface.

Practical Takeaways 

Using multiple surfaces ’increases the movement bandwidth’ of an athlete potentially making them more robust. If you subscribe to dynamical systems theory, changing surfaces is a way to drill the attractors of the movement (in this case, developing pretension around the ankle and whole-body stiffness) while increasing the range of fluctuations (varying surfaces). However, stopwatch sports, such as track may not need to change their environment due to always running on a track with little to no variation.

How could you put this into practise if you only have access to a field?

Option 1 

Various rubber matting can be placed on a field to perform jumps, plyometrics, and sprints on.

Option 2 

Changing footwear; performing some sessions in boots, some in shoes, and some barefoot.

Option 3 

⇒

Placing weight plates or other material on the field; you can use varying heights of the plates as a way to vary surface height when performing exercises, such as pogos.

Using this study as an example, you could perform the PJT straight after your team warm-up and would only take 5-10 min, for example:



DJ 1 x 8



BJ 1 x 8



Unilateral CMJ 1 x 8



180° Jumps 1 x 8



Repeated CMJ 1 x 8

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Then check these out...

© Copyright - Science for Sport Ltd 2016-2020. All Rights Reserved.

James’ Comments “Combined surfaces don't have to be reserved just for PJT, they can also be used when sprinting. I have personally used this approach by putting rubber mats on the ground in random spacing for players to sprint over. In doing so, you drill the sprinting attractor of ‘foot from above’ without having to try cue it.

If the player doesn't sprint with their ‘foot from above’, they'll trip and fall. The varying surface also improves the ability of pre-tension before impact, which is likely why the PJTc group improved their DJ so dramatically.”

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Technology & Monitoring

14

Technology & Monitoring This month’s top research on technology and monitoring.

HOW TO EFFECTIVELY MANAGE

GPS DATA Guillaume, R. et al. (2020) Frontiers in Physiology.

EFFECTIVE PERIODISATION AND TRAINING LOAD MANAGEMENT FOR TEAM SPORT Boullosa, D. et al. (2020) Frontiers in Physiology.

CREATING CONSISTENCY AROUND THE CONCEPT OF AUTOREGULATION Greig, L. et al. (2020) Sports Medicine.

© Copyright - Science for Sport Ltd 2016-2020. All Rights Reserved.

Technology & Monitoring

15

[Abstract]

How to effectively manage GPS data

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

The use of global positioning system (GPS) technology as a monitoring tool for measuring external training load (TL) has become commonplace in many high-level field-based sports, such as soccer or rugby union. GPS data has shown adequate reliability (see HERE), but can be overwhelming as practitioners aim to manage the TL of their athletes.

The authors of this paper first outlined the importance of the objective external measurements provided through GPS in managing TL progression and fluctuation in elite soccer.

Specifically, they identified important parameters to focus on when using GPS as a tool for monitoring (i.e. total distance covered, accelerations, decelerations, high-speed, or sprint running distances), that represents the volume of work performed on the field in training.

Based on fluctuations that are consistent with athlete perception, the proven (see HERE) and applicable GPS metrics that best represent both team and individual external TL measures of volume and intensity include:

The objective of this opinion paper was to provide useful and insightful direction in using GPS data to optimise performance for a team while appreciating the individual’s physical and mental response across the days, weeks, and months of competition.

⇒

Total distance covered

⇒

Distance covered at high-speed running (19.8 and 24.8 km∙h-1)

Using competition loads as reference for each individual, the authors outlined how to safely and effectively calculate and manage the month(s), week(s), and day(s) of training data for best practice in planning and monitoring training in order to achieve the ultimate goal of reducing injury risk and enhancing player performance on the field.



Distance covered at sprint running (>25.2 km∙h-1)



In-game maximal speed



The number of accelerations (≥3 m∙s-1) and decelerations (≤3 m∙s-1)

⇒

Considering the average, minimum, and maximum values of each for analysis.

To provide an individualised profile for competition performance values, specific GPS data, using the average of the best five values recorded during official games or research-based values (see HERE and HERE) were used as a reference.

⇒ 

GPS in-game metrics are multiplied by a weighted factor (see HERE) to calculate monthly, weekly, and daily volume targets to appropriately progress and manage TL. Proper management of TL is best accomplished by observing the difference between what is planned and what actually occurs in a given session, adjusting ensuing sessions based on target volume and intensity.

Practical Takeaways 





Individualising speed thresholds based on a combination of maximum aerobic speed (see HERE), maximal sprint speed, and anaerobic speed reserve has a higher association with perception of TL (see HERE). However, general team thresholds show similar sensitivity and are likely more practical since frequent testing is not traditionally possible during training and competition.

When progressively increasing TL across a month, aim for roughly a 10% increase each week. To generate specific target values, multiply the in-game performance reference by an arbitrary weighted factor. For example, the weighted factor for weekly total distance could be: 

Week 1: 2.8, week 2: 3.2, week 3: 3.4, week 4: 2.6



Therefore, if a midfielder has a reference value of 12,045m for total distance in a competition, the goal and/or limit for ‘week 1’ would be an accumulated total of roughly 33,700m (e.g. 12,045 x 2.8). This would progress to upwards of 41,000m by ’week 3’ (e.g. 12,045 x 3.4) in order to progressively build chronic workload.

With weekly competitions, the week is organised so that game day represents the greatest training load and subsequent days are a percentage of those volumes and intensities. Days three and four post-game are the best opportunities to achieve higher TL before tapering down to allow for recovery (see Figure 2 within the article).





For a given session, the target volume and daily weighted factor of each GPS metric (e.g. high-speed running distance) is merely a percentage of the in-game reference.

Coaches can use GPS metrics from training to understand how various volumes and intensities accumulate for a specific drill and what field dimensions to use (see Figure 3 within the article).

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Cody’s Comments “The valid and reliable feedback gained from GPS data is what bolsters proper management of athlete performance. More than just monitoring, GPS serves as an assessment tool, helping to create reference points that allow training and performance to be analysed. Allowing for guided prescription of the necessary volumes that are achieved in competition and need to be developed in training, as well as individualised capabilities of intensity as markers of performance potential.

With these metrics, coaches can sequentially map out the volume and intensity targets for the days, weeks, and months of training in an effort to optimise performance and reduce risk of injury due to not enough or too much training. Which can then be continuously monitored and adjusted based on what actually plays out on the field. During a competitive season in particular, linear design is not a reality and coaches should reference external GPS measures with other internal assessments (e.g. HRV or ratings of fatigue), constantly fine-tuning training volume and intensity.”

Technology & Monitoring

16

[Abstract]

Effective periodisation and training load management for team sport OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Reducing time-loss, non-contact injury is a primary factor in an athlete’s and team’s performance (see HERE). Non-contact injuries can occur when the load experienced exceeds an athlete’s given capacity. Employing a concept like acute: chronic workload ratio (ACWR) (see HERE) has the potential to monitor training demands and identify periods of time where an athlete’s risk of injury could be greater.

The authors compared commonly-used performance indicators of individual and team-sports, recognising the importance of physiological potential (i.e. VO2max, muscle power) for individual sport athletes, compared to the development of technical skills and tactical behaviours within team-sports, as being a primary training target for optimising success.

Further highlighting the difference in training and competition calendars, where a team-sports’ season is typically longer, with greater frequency of competition.

 For holistic athlete development,

The purpose of this opinion article was to outline strategies to best manage training load and reduce injury risk in team-sports.

 An individualised approach to prescribing various training elements and managing workload is most effective for monitoring, even in the team sports environment.

These aspects influence both periodisation  Training elements can be specifically and monitoring of training, but by targeted when sports coaches, managing each athlete individually and strength coaches, and medical staff identifying influential internal and external collaborate on an athlete’s specific training load factors, an effective strategy history, weaknesses, and identifying can be designed for each sports shared training goals for more environment. influential performance in competition.

Practical Takeaways 

As an S&C coach, you should individualise training based on an athlete’s given training and injury history, as well as weaknesses identified through assessments in order to optimise performance. Identify assessments that represent key performance indicators (e.g. jumping ability for a goalkeeper).



Collaborate as a staff early and often for optimal effectiveness. This begins with open communication regarding specific player development, plus shared monitoring and periodisation plans at the start of a macrocycle.



ACWR is most effective when monitoring a combination of individual internal and external factors.



periodisation should incorporate planning of multiple elements (e.g. gym-based training, recovery strategies, psychological coaching, nutrition education, and sport-specific skill development) throughout a macrocycle.



Quantify external training load volume for reference from either global position system data or a simple measurement of total training time.



Quantify internal training load based on specific measurments of heart rate variability or a simple subjective rating of athlete recovery.

Coaches must be careful to not overload the athlete with information and performance enhancement strategies all at once. The timing of when and how to implement education on nutrition, psychology, or recovery should be periodised in accordance with the macrocycle. 

Nutrition education should start simple (e.g. daily calorie intake and hydration), and progress in complexity as each athlete gains understanding.



Stress management and goal setting are great starters for psychological performance strategies prior to a competitive season.



For recovery, improving and encouraging sleep is the best intervention during non-competition periods, and specific modalities (e.g. massage, hydrotherapy, compression) are best to be implemented during periods of condensed competition (see HERE).

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Cody’s Comments “Team-sports can adopt training and monitoring techniques used in individual sports to reduce injury risk and enhance performance potential.

Measuring and managing the volume and intensity of workload (e.g. ACWR) is a start, as is individual athlete observation, communication, and collaboration from coaches and medical staff regarding the planning and implementation of training and monitoring strategies. Thomas Reid first said (see HERE), “A chain is only as strong as the weakest link” and for a team to be most successful, an individualised approach to monitoring training load and training intervention is necessary. Although more timeintensive, the return (e.g. performance enhancement and reduced injury risk) is well worth the investment.

Another noteworthy investment is planning and periodising athlete education across the macrocycle. Respecting the multifactorial development necessary to boost the effectiveness of training through improved recovery habits and athlete well-being. Creating a progressive curriculum to assist athletes in learning and application of information that does not interfere with but rather prepares athletes for the competitive season.”

Technology & Monitoring

17

[Abstract]

Creating consistency around the concept of autoregulation OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Autoregulation of training was first presented in the 1940s (see HERE) as a way to optimise and adapt training load based on an individual’s fluctuating response to stressors (e.g. fatigue, soreness, motivation). In the decades since creativity and technology have evolved this method into numerous variations (e.g. perception-based repetitions in reserve (RIR) or technological velocity-based training (VBT)). However, consistency in the application of this process is important, especially when implementing resistance training concurrently with sport-specific tactical or technical training. Coaches should be able to lean on collective research for the most effective autoregulation methods.

The authors first provided a summary of the concept of autoregulating training, highlighting its potential benefits, as well as the range of ways to adapt it as a high- or low-frequency method regarding performance measurement and programming adjustment.



Autoregulation is a way of aligning the intended stimulus and targeted progress with the actual dosing of load (e.g. volume or intensity) based on evaluation or athlete appraisal, where fluidity and adaptability create a more productive and enjoyable training environment.



Measuring performance as a representative

This review proposed a theoretical outline for using autoregulation methods within the training environment and offered practical application opportunities by combining methods from the past and present.

Utilising Banister’s fitness-fatigue model (see HERE), working definitions were provided for primary terms associated with athlete readiness and response to training. Then using contemporary concepts (i.e. RIR and VBT) application of autoregulation methods were outlined for both a single session, as well as across multiple sessions.

In addition to this, the authors then identified ways to measure performance, minimise error, and allow for flexible and productive training.

Practical Takeaways 

RIR (see HERE) is a subjective autoregulation method to better prescribe and manage exercise intensity. For best results, offer athletes a target range (e.g. 8-12 reps) to help guide their weight selection. This technique is great for athletes training at home with limited weight options (e.g. only a pair of 15 kg dumbbells or bodyweight exercises), allowing for adaptive increases in volume based on perceived effort level.



VBT (see HERE) in an objective autoregulation method to manage resistance training volume and intensity. Establishing an individualised load-velocity profile for a given exercise is preferred. Volume can be guided by velocity loss within a set, based on a percentage decrease (see HERE) or an absolute cut-off value (see HERE). Intensity can be guided by offering an average velocity range (e.g. 0.45-0.55 m.s-1) to best target either strength or power specificity.



When using pre-training performance measurements (e.g. countermovement vertical jump) to autoregulate training, establish a minimal individual difference (see HERE) by performing multiple trials across two days. With those metrics, calculate the standard deviation and use that range as the confidence interval to showcase performance potential. When testing performance pre-training, a result outside this range alerts coaches as to whether a change is significant, and modifications are needed. For best results, select a test that does not interrupt the time-efficiency of a session and one that is similar to the qualities being trained (e.g. jumping for speed- or power-related activities, or isometric strength measures for strength training).

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summation of fitness, fatigue, and readiness before or within a session can help provide feedback and guide adjustments to training prescription (e.g. intra-, inter-session, and across mesocycles) based on anticipated response.

⇒

Autoregulation allows training to be individualised based on preceding influences, current performance, and the targeted stimulus.

Cody’s Comments “This review does an excellent job outlining the fitness-fatigue model and using it as a foundation to clearly define what performance is. The authors highlight that training creates both a positive (i.e. fitness) and negative (i.e. fatigue) result, and that athlete readiness is influenced by training and non-training stressors. Further, appreciating the athlete as a fluctuating biological system is why we monitor because performance is a moving target, adaptability is unpredictable, and readiness is the difference between current ability and potential.

As coaches plan training, it is important to adapt to fluctuations in readiness to allow for long-term adaptations and avoid over- or under-training. Autoregulation is about creating conditional or ‘if-then’ statements that best manage an athlete’s training load.

These rules help to eliminate the guesswork around training prescription and create individualised, immediate, and actionable steps based on real-time performance or perceptual feedback. Actions that are protective, supportive, and encouraging to the athlete, improving training progress and adherence.”

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Fatigue & Recovery

18

Fatigue & Recovery This month’s top research on fatigue and recovery.

ASSESSING MENTAL FATIGUE IN

ATHLETES AND ITS IMPLICATIONS FOR PERFORMANCE Verschueren, J. et al. (2020) Medicine and Science in Sports and Exercise.

MAKING SENSE OF TRAINING LOAD MARKERS FOR IMPROVING AEROBIC FITNESS IN SOCCER Ellis, M. et al. (2020) Science and Medicine in Football.

SPEED ENDURANCE PRODUCTION VS. MAINTENANCE TRAINING IMPLICATIONS Ade, J. D. et al. (2020) Science and Medicine in Football.

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Fatigue & Recovery

19

[Abstract]

Assessing mental fatigue in athletes and its implications for performance OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

In sport, common functional performance tests (FPT) (e.g. maximal jumps, balance tests) are often used to determine the current recovery status of an athlete. Physical fatigue is known to negatively impact FPT, however, fatigue is a multidimensional phenomenon that may not just be impacted or caused by physical fatigue alone (see HERE and HERE), for example, mental fatigue may also lead to negative FPT performance.

Fourteen healthy adults (22 ± 2 yr) completed both an experimental and control trial which comprised of a Stroop Test (see video below) and a 90 min documentary (to avoid boredom and ensure mental engagement), respectively.

FPT

Prior to and after both trials, rating of perceived exertion (RPE) was recorded and a mental fatigue visual analogue scale (M-VAS) (see HERE) was completed alongside the following FPTs:



The authors of this study investigated the effect of mental fatigue on commonly used FPT and performance during neurocognitive FPT.

⇒

Countermovement jump (CMJ)

⇒

Single-leg hop (SLH)

⇒

Y-balance test (YBT)

⇒

Reactive balance test (RBT) (as a neurocognitive FPT)

Following the completion of each trial, the participants had to rate their perceived mental and physical exertion again and complete a subjective workload task (see HERE).

Practical Takeaways 

Mental fatigue assessments, such as the RBT test, should perhaps be considered alongside physical fatigue assessments in order to increase the understanding of fatigue with athletes. Considering RBT was influenced by mental fatigue, determining its magnitude using statistics like effect sizes (see HERE) may provide more context for any negative influence on performance and injury susceptibility in our athletes.



Considering mental fatigue seems to have no negative implications on power, balance or strength, practitioners may wish to plan different types of sessions during times of mental fatigue. For instance, if feasible, the prescription of gym-based over field-based exercise may be favoured during such times, due to the perceived lower decision-making, reactivity, balance, and multiple stimuli requirements of gym-based exercises.



The findings herein remind us that although commonly utilised markers of fatigue (i.e. CMJ) may indicate that our athletes have ‘recovered from fatiguing stimuli’, this may not necessarily be the case. FPT, such as those utilised in this study, are perhaps just not sensitive enough to represent all aspects of fatigue. Therefore, being cautious with our interpretation of when an athlete is ‘recovered’ is probably important and including more multidimensional assessments, such as the RBT, is perhaps warranted.

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⇒

Participants accuracy, but not reaction time, on the RBT was significantly lower after the experimental trial in comparison to the control trial.

No differences between the experimental and control groups were found for the remaining tests.

Markers of Mental Fatigue



Higher levels of mental fatigue based on the M-VAS score was observed after the experimental when compared to the control trial, as well as after the second set of FPT in comparison to the first set.

⇒

After the subjective workload task, mental and temporal demand, effort, and frustration were higher after the experimental trial than after the control trial, yet intrinsic motivation did not differ between the trials.



RPE did not differ between experimental and control trials.

Owen’s Comments “This was an interesting study that challenges our thinking of measuring neuromuscular fatigue markers and making conclusions on recovery status based only on physical performance. As with many athlete monitoring tools, it is important to understand what information a marker can and cannot give you, meaning the inclusion of mental fatigue markers may be justified.

Until now, it doesn’t seem that any prospective longitudinal studies are available that investigate the association between mental fatigue and physical performance or injury susceptibility over time. Such investigations may provide valuable information for practitioners in the field and open our eyes up to a new part of the puzzle within athlete development.”

Fatigue & Recovery

20

[Abstract]

Making sense of training load markers for improving aerobic fitness in soccer OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

The development of an effective training plan to improve the aerobic capabilities of soccer players is important, as they are frequently required to recover from the high-intensity actions that occur during competition periods (see HERE). In order to interpret their effectiveness, several variables can be collected and linked to changes in fitness levels. Internal load variables (e.g. heart rate) generally have the strongest relationship to increases in fitness, yet evidence of this in soccer is sparse.

Nine professional youth soccer players (17 ± 1 yr) from a category 2 English Premier League academy were monitored across a 6-week pre-season. An incremental lactate threshold test was completed at the start and end of pre-season to determine aerobic fitness changes by measuring:

The mean S2 changed from 9.87 km.h-1 to 11.9 km.h-1 and the mean S4 changed from 13.3 km.h-1 to 15.0 km.h-1. Mean MAS improved from 18.6 km.h-1 to 19.2 km.h-1.

Therefore, the purpose of the study was to determine the importance of different measures of load for improving aerobic fitness in soccer players.



Resting heart rate (HRrest) and maximum heart rate (HRmax)

⇒

Maximal aerobic speed

⇒

The relationship between blood lactate concentration

The internal load markers of iTRIMP and luTRIMP had strong relationships with changes of aerobic fitness at S2 and S4. Out of all the external load markers, PL displayed the strongest relationship with S2, yet this was deemed only moderate.

and exercise intensity (i.e. speed at 2 (S2) and 4 (S4) mmol.L-1, respectively) Throughout pre-season the following markers were collected: Internal Load



Banister’s (bTRIMP), Lucia (luTRIMP), Edwards (eTRIMP), and individual (iTRIMP) TRIMP



Training load as measured by session rating of perceived exertion (sRPE)

External Load



Total (TD), high-speed running (HSR, 14.4-19.8 km.h-1), very high-speed running (VHSR, 19.8-25.2 km.h-1), and maximal sprint (MS, >25.2 km.h-1) distance



Player Load (PL)

Practical Takeaways 

If practitioners are seeking to monitor or predict the efficacy of a training programme to improve aerobic fitness (specifically, treadmill-based lactate threshold capacity), utilising markers of internal load seem to be far superior to markers of external load.



In order to better estimate changes in aerobic fitness across the course of a training plan, individualising markers of training load seems to be an important consideration. Therefore, when deciding upon markers of internal load for the monitoring of training and subsequent training outcome, iTRIMP appears to be the most accurate in comparison to other variants of TRIMP, as well as sRPE. See the article below for information on how to determine iTRIMP.



If utilising systems to provide information on external load, PL accumulation across the duration of a training plan may be the most favourable selection to determine changes in aerobic fitness. However, it is important to note that iTRIMP, as a measure of internal load, was far superior to PL.



If utilising iTRIMP within your cohort of athletes, the thresholds presented in this study may provide some form of benchmark, where 571 or 643 AU (iTRIMP) was required for athletes to maintain S2 and S4 values, respectively. However, specific internal or external load values cannot necessarily be generalised to athletes at a different level, age group or training regime. As such, it would be advised for practitioners to recreate such investigations in their own cohorts.

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Owen’s Comments “Considering the importance of aerobic fitness in soccer, a means of determining aerobic fitness changes via internal and external load markers is vital. In addition, considering the vast number of load variables utilised in elite sport to monitor athletes, more research surrounding their sensitivity for specific purposes is warranted. For those with access to equipment that allows the quantification of individual lactate threshold scores, the utilisation of iTRIMP for determining optimal internal load exposure for maximising aerobic training effects is suggested, especially considering its superiority over the TRIMP variables that did not include lactate values (i.e. bTRIMP and eTRIMP).

The protocol used in the present study is a valid and reliable means of obtaining an individual’s lactate threshold. However, this measure of ‘aerobic fitness’ involved continuous and linear based running on a treadmill assessment, which perhaps doesn’t hold great specificity to the activity of soccer players. As such, it can be questioned whether this correctly identifies or represents aerobic fitness during a multidirectional and intermittent-based sport, especially considering the relationship between training load measures and training outcome will change dependent on the type of test (see HERE).”

Fatigue & Recovery

21

[Abstract]

Speed endurance production vs. maintenance training implications OBJECTIVE

WHAT THEY DID

The prominence of high-intensity actions, such as sprinting and changing direction during soccer matches is ever increasing. Therefore, methods for developing a player’s ability to perform these actions is of great importance. Speed endurance production (SEP) and speed endurance maintenance (SEM) are two methods that can elicit several favourable physiological improvements. Yet, a solid understanding of the individual benefits and acute fatigue inducement of each method in game-specific scenarios is absent.

Twenty male soccer players (10 elite, aged 18 ± 1 yr; 10 subelite, aged 23 ± 3 yr) performed a SEP and SEM drill specific to their position (centre back, full back, centre midfield, wide midfield, or forward) with different work to rest ratios. Each drill consisted of eight exercise bouts lasting approximately 30 sec which were interspersed by either 150 sec (SEP) or 60 sec (SEM) of passive recovery. The following markers were collected pre- and immediately post-session:

This study investigated the difference in physiological characteristics and acute fatigue of soccer players during position-specific SEP and SEM protocols.

Physiological and Perceptual ⇒

Heart rate (mean, peak, and time spent >85, 90% max)

⇒

Rating of perceived exertion (RPE)

⇒

Blood lactate concentration (pre- and post-drill)

Time-motion ⇒

WHAT THEY FOUND Neuromuscular Function Markers ⇒

Greater reductions in VCMJ immediately after SEP, but

⇒

HCMJ reduced immediately after SEP and SEM, as

after 24h for SEM. well as after 24h for SEM. ⇒

Time-motion Markers ⇒

High speed running (>14.4 km.h-1) and very-high speed running (19.7-25.2 km.h-1) and sprinting (>25.2 km.h-1)

⇒

Accelerations and decelerations (>3 m.s2)

⇒

49-218% more very high-speed and sprinting distance

⇒

7-10% greater mean peak and average speed in the

⇒

No difference in acceleration and deceleration demands

in the SEP vs. SEM drill.

SEP vs. SEM drill.

between both drills.

Neuromuscular Function (sub-elite players only) ⇒

Bilateral vertical countermovement jump (VCMJ)

⇒

Vertical drop jump (VDJ)

⇒

Horizontal countermovement jump (HCMJ)

Practical Takeaways 

For practitioners looking to elicit greater external load demands (e.g. more distance covered at high, very-high and sprint speeds, or higher peak or mean speed reached) during a speed endurance drill, the SEP seems to be the favoured selection. As such, in cases when players have missed out on high-speed exposure such as during a competitive match, utilising the SEP as a top-up for players may be a useful tool.



Alternatively, if practitioners are looking to expose their athletes to a greater internal load stimulus (e.g. higher heart rate response or subjective difficulty), the SEM drill may be more suitable. Having said this, the blood lactate values postSEP drill were higher than that of the SEM drill for this study, so careful consideration for the aims and objectives of the session are required.



As the speed endurance drills elicited significant reductions in subsequent post-drill power capacity, it may be important for practitioners to carefully plan where the implementation of these drills fit into a wider periodisation plan. This is because it is unknown as to what extent this fatigue-inducement may influence the subsequent ability to complete further tasks at a high-level whilst minimising injury risk, either in the same session or in subsequent sessions later on in the week.

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5-12% more total distance and high-speed distance in the SEP vs. SEM drill

Total distance

⇒

A small change but immediate change in VDJ reactive strength index was seen after SEP and SEM.

Physiological and Perceptual Markers ⇒

4-10% greater mean and peak HR in the SEM vs. SEP drill.

⇒

4% higher RPE in the SEM vs. SEP drill.

⇒

6% higher blood lactate in the SEP vs. SEM drill.

Owen’s Comments “This was a very applied study that provides several real-world applications to us as practitioners. One aspect of work that may benefit from such research is the requirement to maintain fitness levels of non-playing players. Depending on training and fixture schedules, squad size, and managerial styles, practitioners are often faced with the challenge of maintaining sufficient acute and chronic workloads for those that miss out on match stimuli. As such, having the capacity to implement speed endurance drills such as those presented in this study and understanding their influence on an athlete’s acute response is very useful.

As was correctly indicated in the study limitations, the small sample size of subelites that were tested for neuromuscular function makes it hard to infer data to elite cohorts and cannot be conclusive, considering only ten individuals were assessed, which means future studies are required.”

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Youth Development

22

Youth Development This month’s top research on youth development.

FINDING THE BALANCE: THE ROLE OF

ASYMMETRY IN PERFORMANCE AND INJURY PREVENTION Fort-Vanmeerhaeghe, A. et al (2020) The Journal of Strength and Conditioning Research.

INCORPORATING INJURY PREVENTION PROGRAMMES INTO A SCHOOL CURRICULUM Sommerfield, L. M. et al. (2020) International Journal of Sports Science and Coaching.

THE PHYSICAL COST OF ADIPOSITY IN YOUNG FEMALES Pacewicz, C. E. et al. (2020) Measurement in Physical Education and Exercise Science.

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Youth Development

23

[Abstract]

Finding the balance: the role of asymmetry in performance and injury prevention OBJECTIVE

WHAT THEY DID

In high performing youth athletes, injuries can be higher than the normal population due to a typically greater training volume and intensity. Despite this, few studies have investigated the association between injury-risk factors and actual injury incidence amongst youth athletes, which is important for participation.

Following a one-week familiarisation protocol, eighty-one team-sports athletes (14-18 yr) completed a warm-up consisting of light movement, dynamic stretches, and progressive acceleration and jump movements. Following this, all participants completed the following tests:

The aims of this study were to 1) investigate the association between inter-limb asymmetries and non-contact lower limb injuries, and 2) assess how these may influence performance parameters.



Countermovement jump (CMJ) (m)



Single-leg countermovement jump (SLCMJ) (m)



One-leg hop distance (OLHT) (m)



30m sprint (sec)



V-cut test (sec)



Repeated sprint ability (RSA) (sec)



30-15 intermittent fitness test (km.h-1)

Inter-limb asymmetries were calculated using the following formula: (Highest performing limb–Lowest performing limb/ Highest performing limb) × 100. All results were then analysed retrospectively against injury and performance measures collected for the 2017-2018 season.

Practical Takeaways 

The measurement of asymmetries in team-sports youth athletes is very important and the modern coach is always looking for time-efficient methods.

Therefore, I would recommend the SLCMJ test (3 trials on both limbs, separated by 30-sec recovery). Let’s say that the average force of the left limb was 679.69N and the right was 397.76N, then the percentage difference can be calculated using the following sum (which has also been explained in the video below): Percentage difference: 100/(max value)*(min value)*-1+100 SLCMJ

Example: 100/(679.69)*(397.76)*-1+100 = 41.48% between-limb asymmetry. 



When interpreting these results, it is important to recognise that asymmetry thresholds of 10-15% are relatively normal (see HERE). Additionally, the different movement demands of various sports further impact the imbalance thresholds of athletes (discussed by Chris Bishop below). However, if the imbalance is greater than 10-15%, coaches need to rectify this, and I would look to do this using the following exercises: 

High skipping with a half every 5 skips (2 x 5 per limb, 20-sec recovery)



Diagonal single-leg bounds (4 x 6 with a 30-sec recovery)



Medicine ball chest pass on one leg (4 x 8 with a 120-sec recovery)



Skater squat (3 x 5 with a 60-sec recovery).

The above programme reduces asymmetry by developing single-leg strength, control, and stability. In addition, single-leg exercises allow other supporting structures to absorb and produce force, leading to adaptation. In using these exercises, Sannicandro and colleagues (see HERE) reported that two, 30-min sessions over six-weeks reduced asymmetry from 9.0 to 3.7% in an OLHT, and 10.8 to 3.2% in the side-hop test. Coaches can use these thresholds as a target with their athletes.

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WHAT THEY FOUND



A total of 72 injuries were recorded, with 76.4% in the lower limb.



46 non-contact injuries were reported, with 4.2% occurring in handball, 30.9% in basketball, and 26.7% in volleyball players.



No differences were reported between males and females.





Athletes who sustained an injury presented larger asymmetries during bilateral CMJ and SLCMJ, SLCMJ, as well as an inability to reach higher vertical jump heights.

Non-injured athletes recorded an asymmetry of 9.7% in males and 7.7% in females. In contrast, injured athletes reported far greater limb asymmetries 17.1% and 12.8% (males and females, respectively).



Regarding performance, non-injured athletes produced significantly superior performances in CMJ and SLCMJ, however, no differences were reported in OLHT, 30m sprint, V-cut test, RSA, or the 30:15 fitness test.

Tom’s Comments “The current study provides a fantastic insight into the importance of having a qualified S&C coach. The findings indicate that players who present larger asymmetries and reduced performance in various jumping tests (i.e. vertical, CMJ, and SLCMJ) should be marked at a greater predisposition to injury. Therefore, our role as coaches should be to reduce this by ensuring that athletes are challenged in both single-limb (unilateral) and doublelimb (bilateral) strength.

Exercises such as single-leg Romanian deadlifts, reverse lunges, and pistol squats should develop unilateral performance, which in turn, should reduce asymmetry.

The attached article explains the mechanisms for this, suggesting that increased range of motion, joint stability, and individual-limb strength are likely contributors. The podcast below also acknowledges the role of bilateral strength as a factor in reducing asymmetry. To support bilateral strength, exercises such squats, deadlifts, and CMJ are important to drive neural strength adaptations, such as motor unit recruitment, rate of force production, and intramuscular coordination (see HERE).”

Youth Development

24

[Abstract]

Incorporating injury prevention programmes into a school curriculum OBJECTIVE

WHAT THEY DID

Physical activity possesses many positive benefits on the health and wellbeing of the youth population. Young people who participate in sport are more likely to continue doing so as adults but are also at an increased risk of injury. Increased injuries are thought to occur as a result of increased training and competitive loads, coupled with underdeveloped athletic competencies (e.g. the ability to jump and land properly).

Ninety-two female students (14 yr) from a girls’secondary school completed the following tests:

The aim of this study was to investigate the role of a school-integrated injury prevention programme on skill and performance in young females.

⇒

10- and 20m sprints (sec)

⇒

Countermovement jump (CMJ) (cm)

⇒

Isometric mid-thigh pull (IMPT) (N)

⇒

Y-Balance test (cm)

⇒

Back squat assessment (BSA)

⇒

Drop vertical jump (DVJ) (rated via scale)

⇒

Mirwald maturation test

⇒

Beep test

WHAT THEY FOUND



Movement skills and balance improved in the INT group over a 23-week period. In particular, Y-balance measures were greater in the INT group.



From baseline performance measures, the INT group significantly outperformed on the follow-up test when compared to the CON group, apart from in their right and left CMJ power.

BSA and DVJ were found to improve significantly compared to the CON group.



Although the INT group performed better than the CON group, improvements in IMTP, relative IMTP, 10m sprint, single- and double-leg CMJ power and height, and left-leg Y-balance scores were reported through normal physical education participation.



The INT group participated in significantly more physical activity per-week when compared to the CON group (4.15h vs. 2.19h).

Upon completion, forty-three students were used as the intervention group (INT), and forty-nine for the control group (CON) based on their physical ability. Ability was measured using the 10m sprint time and beep test data to ensure that the normal curriculum could resume around this study.

The CON group participated in their normal PE curriculum. However, the INT group performed a programme consisting of low-level plyometrics, agility, lower-body strength, core stability, and balance for 23-weeks. Pre- and post-intervention scores were then compared.

Practical Takeaways 

When working with large groups, it’s important that your injury prevention programmes are easy to teach, so that others with less of a ‘coaching eye’can still provide value. 2-3 sets of 8-10 reps on each exercise are a fantastic balance of speed (to avoid tedium) and duration (to ensure quality) as recommended by the Fifa 11+ protocol (see HERE). The warm-up provides a fantastic opportunity to explore these exercises in a step-by-step approach.



More specifically, I like my warm-ups to include a mobilising block (ankle = leaning lunges, hip = hip rolls, and thoracic spine = Spiderman stretch). Once these are complete, I move into some low -level landing drills (see HERE) and remedial plyometrics (see HERE).

These are fairly easy to teach to staff, and still follow a logistical RAMP warm-up process (see HERE) without being to labour intensive for staff and can develop student-leadership qualities.



Out of the 160 children that I work with, 62% are training and playing over 14 hours a week, therefore, it’s very important that we provide educational content for parents. The video below is a fantastic framework to follow, as both athletes and parents need to understand the relationship between load, recovery, and injury prevention. Where possible, getting athletes to fill out what their week looks like as ‘homework’and getting their parents to reflect on this with you is a great way to build a relationship.



By covering injury-prevention in the school day, Dr James Voos in the podcast below suggests that there is less extracurricular load.

Moreover, James covers a fantastic topic of coping with demanding parents. Education, rapport, and knowledge-transfer are thought to be the best ways to ensure long-term change.

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Tom’s Comments “These types of studies are fantastic as they present programmes and results that are immediately applicable. When combined with articles such as the FootyFirst Manual (see article below), teachers and coaches can build up an expansive list of exercises which can be delivered based on their ability. I’ve just designed my own injury-prevention programme at my school. I definitely over-estimated the students' ability, so would advise that all movements are broken down into simple movements. For example, a majority of our students couldn’t support their weight on their arms, so an activity like a bear crawl had to be regressed to a front-support hold.

Studies in schools can be really useful, as they often show high adherence, control (e.g. time and location), and real-world applicability. From this study, movement skills and balance improved in post-PHV females. In the future, studies should look at analysing the effects on those pre and circa PHV, as Mirwald results found that 95% of participants were post PHV. Future authors must look at the optimal doseresponse relationship, as 40 min in most schools will be a whole PE session.”

Youth Development

25

[Abstract]

The physical cost of adiposity in young females

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Amongst youths, high levels of adiposity (body fat) are unfortunately rising, showing a strong link with hypertension, cardiovascular disease, and diabetes.

From a coaching perspective, high levels of adiposity are not ideal, as children possess lower motor performance and proficiency. These children are then less likely to participate in sport, and struggle to regulate their weight.

All participants (n = 267) included in this study were aged between 8-16 yr, with data retrospectively analysed using a study over a 32-year period designed to measure motor performance (see HERE). Body adiposity was calculated from three sites (triceps, subscapular, and abdominal) using Harpenden skinfold callipers. Growth was analysed using a latent growth curve model, and maturation was calculated using the cubic spline method, using the following sum for females:

Individuals with higher levels of adiposity were found to have reduced jump and reach and 30 yd dash performance. Although the effect sizes were small, this would suggest that higher levels of adiposity were associated with reduced performance. Furthermore, adiposity measures continued to increase with age.

The aim of this study was to investigate if adiposity in children of a varied maturation status impacts their motor performance.

Maturity offset (years) = -7.709133 + (0.0042232 x (age x stature)).

To measure motor performance, participants performed a jump and reach test near a wall as an indicator of lower-body power and coordination, and a 30 yd dash between two cones measured to the nearest 0.1 sec.

Practical Takeaways 





To combat the rise in adiposity and reduced motor performance, bodyweight exercises are a fantastic place to start as these lend to movement quality and control. I would start with ½ bodyweight squats, wall RDLs, seated overhead band presses, kneeling pushups, reverse crunches, kneeling planks, and short duration boxing/ cycling work. For these exercises, I would look to do 2 x 8 reps for each, improving to 2 x 10 after two weeks, and 3 x 8 on week four.

To track intensity, the 6-20 RPE scale described in the video below is a great idea. Getting children to add their own emojis to this, as demonstrated is a great idea to develop their knowledge of intensity.

Whilst it is important that we develop motor performance from a young age, developing other factors that influence adiposity is important. In the attached article, Lynch and colleagues introduce a lesson template which can be used with children. This resource suggests the covering the plate method (see HERE), which is all about fruit and vegetables, screen time, physical activity, sugary drinks, sleep and breakfast, portion sizes, and snacks. According to Lynch and others, these are the most important factors for youth to control weight.

In the reviewed study, performance started to drop on average after the age of 14 yr. It’s important that we provide an appropriate challenge where everyone feels valued and that they play a part in sport. For example, in an agility game, providing targets with varying levels of ease and point systems ensures that everyone contributes and can compete from a psychologically safe place. In turn, these individuals are more likely to enjoy the experience and want to participate in the future.

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On average, at 8 yr old participants were jumping 29.17 cm, which increased to 37.94 cm by 16 yr of age. This was thought to occur naturally as a result of increased age, with small declines occurring after 14 yr of age. In addition to this, no significant interactions were found with maturation.

30 yd dash performance measures improved from 4.88 sec (8 yr) to 2.58 sec (16 yr), with a decrement in performance from 14.5 yr onwards.

Tom’s Comments “This study contributes to our understanding of the various factors, including adiposity, that contributes to poor motor performance. There are, however, some limitations of this study.

First, the data used from this study was collected in 1967 and as a result, may not adequately reflect the youth of today.

Secondly, the measures used in this study (time between two cones for the 30 yd dash and a wall-mounted measuring device for the vertical jump) have been replaced nowadays by timing gates and jump mats.

Changes in adiposity with age can be associated with peak weight velocity (see HERE), however, maturity was found to have no significant interactions with motor performance. During these times, youths are at a heightened risk of injury and require coaches to track and monitor any changes in technique or fatigue. In practice, I see this roughly around 14 yr.

Whilst I’m always excited by increased jump heights and running speeds, I ensure that I revisit fundamental movement and capacity issues (e.g. hinging, drop landings, single-leg stability, eccentric strength) which if not corrected, will increase their injury likelihood.”

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Nutrition

26

Nutrition This month’s top research on nutrition.

CAN CREATINE CREAM REALLY IMPROVE

MUSCLE FUNCTION AND POWER? Whinton, A. K. et al. (2020) The Journal of Strength & Conditioning Research.

THE BENEFITS OF PROBIOTIC SUPPLEMENTATION FOR ELITE RUGBY PLAYERS Harnett, J. E. et al. (2020) Journal of Science and Medicine in Sport.

ARE HYDROGELS ANY BETTER THAN NORMAL CARBOHYDRATE GELS FOR ENDURANCE PERFORMANCES? King, A. J. et al. (2020) International Journal of Sport Nutrition and Exercise Metabolism.

© Copyright - Science for Sport Ltd 2016-2020. All Rights Reserved.

Nutrition

27

[Abstract]

Can creatine cream really improve muscle function and power?

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

It is well accepted that consuming exogenous creatine supplementation for 4-5 days can increase muscle creatine content by ~20% and improve muscle power and strength measurements when performing highintensity exercise (see article below). However, a novel topical creatine cream may offer a new approach to delivering creatine to the muscle via skin absorption through a local area of interest (e.g. the upper thigh), although the efficacy of such a method is yet to be studied.

Using a double-blind, placebo-controlled study, 245 participants (both male and female), during the first phase of the study, had either an acute low-dose (3.5 ml) or high-dose (7 ml) creatine, or placebo cream applied to both the quadriceps 30 min and 15 min before a leg extension exercise protocol, respectively.

Following one-off acute application, no differences were seen with low- and high-dose applications of the creatine cream for peak power, average power, or fatigue index.

Therefore, the aims of this study were to: 1.

Test the ability of the cream to improve exercise performance.

2.

Examine the effectiveness of 7-day loading period on muscle power and fatigue.

3.

See if there is an additive effect when combining the cream with oral creatine.

4.

Observe sex-specific responses to acute- or short-term loading periods.

During the second phase of the study, muscular performance was assessed before and after a 7-day application period with the creatine cream as well as the consumption of an oral creatine supplement.

Subjects consumed 21g of creatine or placebo per day, split into 3 doses of 7g, with the cream applied at the same time of day as the second oral creatine consumption.

The exercise protocol completed by each participant consisted of 5 sets of 15 maximal isokinetic concentric leg extensions per leg separated by 60 sec of rest with 10 min break between legs.

Practical Takeaways 

Interestingly forty-nine participants reported at least one mild reaction to the topical cream, which was related to skin irritation or perceptions of skin temperature change. I would recommend players utilise evidence-based oral creatine protocols (5g daily for maintenance dose) which should not result in adverse skin reactions.



Increasing creatine stores via oral supplementation is greatly supported by strong evidence-based literature and is discussed in depth in the podcast below. For athletes, a quick and easy way to consume oral creatine is to mix within a home-made smoothie or shake and follow either a loading (20g per day for 7 days) or maintenance (5g per day) dosing strategy.

⇒

For weight sensitive male athletes or those with a heightened risk of GI stress applying creatine cream may be an alternative strategy, although this though cannot be translated into female populations at present.

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Improvements in peak (creatine: before application 264 and after application 281 W vs. placebo: before 286 and after 271 W) and average (creatine: before 203 and after 220 W vs. placebo before 224 and after 214 W) power were observed in the leg receiving creatine cream in men following the repeated application, whilst no differences were seen in female subjects.

Although the acute application of creatine cream did not elicit any improvements in peak or average power, it appears that repeatedly applying creatine cream on male subjects will improve peak and average power production of the lower-body.

James’ Comments “Although the idea of rubbing in a creatine cream appears innovative, I am sceptical on the ability for this method to result in favourable outcomes for elite-level athletes.

Unfortunately, nowhere in this manuscript does it provide information on the background training status or age of the participants, and as such, I do not think the prolonged cream application can be translated into athletes yet. This research now needs to be performed with subelite level athletes and then elitelevel athletes to see if it really has any translational potential.

My advice to practitioners reading this would be to focus on consuming oral creatine by way of tablets or powder and follow a solid maintenance or loading protocol as outline in the infographic link.”

Nutrition

28

[Abstract]

The benefits of probiotic supplementation for elite rugby players OBJECTIVE

WHAT THEY DID

High performing athletes strive for nutritional strategies that will aid the recovery process following both training and competition. One nutritional aid used often by these athletes is probiotics, especially due to their ability to regulate increases in melatonin (important for the promotion of sleep) and acetylcholine (important in modifying the perception of pain).

Nineteen elite male rugby union players ingested either a probiotic (n = 9) or placebo (n = 10) for 17 weeks which included eight domestic and nine international weeks of competition.

The authors of this study assessed the efficacy of 17 weeks of a commercially available probiotics supplementation amongst international rugby players during a domestic and international competition season on their sleep, motivation, and muscle soreness.

Two probiotics were used: Ultrabiotic 60TM and SBFloractivTM, whilst a placebo pill was also used and was identical in size, weight, and packaging to the probiotics. All players consumed the tablets twice daily with food.

Using an app designed specifically and exclusively for this study, the players provided subjective ratings for sleep quantity (self-reported hours) and quality, motivation, muscle soreness (rated 1-5 Likert scale), and leg heaviness (rated 1-10 Likert scale) twice per week.

Within 30 min after waking, a passive drool saliva sample (~1 ml) was collected twice per week, stored and later analysed for melatonin and C-reactive protein (CRP).

Practical Takeaways 





Considering probiotic use is associated with an antiinflammatory effect and also improved immunity (see article and infographic below), practitioners who currently do not provide probiotics to their athletes may consider its use (e.g. one high strength tested probiotic per day).

The association between disrupted sleep and chronic pain is well established with a classic two-way interaction – disturbed sleep with increasing pain, and chronic pain disturbing sleep. With this in mind, there was a moderate positive association between improved sleep quality and higher motivation scores for those who take probiotic supplementation (which was a new finding). Therefore, a long-term supplement strategy of probiotic supplementation in elite-level athletes may yield favourable effects on both self-reported muscle soreness and sleep quality, and should be considered by practitioners with their athletes.

Alternative options to supplementation include increasing high-biotic foods like Greek yoghurt, kefir, pickles, kimchi and some cheeses.

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WHAT THEY FOUND



Although there were no significant effects or interactions for melatonin or CRP, self-reported muscle soreness was ~0.5 units lower in the probiotic group (3.5 units) compared to the placebo group (3.1 units). This was also reflected in both the domestic (3.5 v. 3.1 units) and international (3.4 v 3.0 units) stage of data collection, respectively.



Increased self-reported muscle soreness was correlated with an increase in CRP concentration in the probiotic group across both the domestic and international periods.

Further, muscle soreness increased when motivation, sleep quantity, and quality declined, whilst leg heaviness increased.



During the international competition, approximately 30% of the variation in sleep quality was attributed to sleep quantity and muscle soreness in the probiotic group.

James’ Comments “This study holds very strong ecological validity considering the homogenous study cohort of international level athletes which only strengthens the results shown and the authors should be credited for conducting this research during both domestic and international rugby union competition.

If practitioners do not have the budget to implement a probiotic supplement regime with their athletes, then food first approaches for increasing probiotics can be used, which is also discussed in the podcast below. Further, purchasing of high strength probiotics supplements could be saved for use during intensified fixture periods of international travel blocks.”

Nutrition

29

[Abstract]

Are hydrogels any better than normal carbohydrate gels for endurance performances?

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

A sliding scale of carbohydrate (CHO) consumption is suggested based on the event fuel needs (e.g. 6 g.kg-1 body mass on match day for team sport athletes or 2-6 g.kg-1 body mass for training) particularly when considering both intensity and the duration of the exercise. High CHO intake should be consumed in training prior to competition to ‘train’ the gut and maximise CHO nutrient uptake from the stomach and into the muscles.

An electronic database search was performed for studies published up to May 14, 2020, with an eligibility criterion of:

Exercise performance was similar between maltodextrin and fructose (MD+F) hydrogels and isocaloric MD+F fluids or noncaloric hydrogels. Overall non-significant relative performance changes between 1-4% were reported across the available studies.

Recently, specialised sports gels, using “hydrogel technology” (see video below) have become commercially available and are cited to be the “world’s fastest sports fuel”.

However, to date, this claim has been made in the absence of scientific validation.

With this in mind, the authors wanted to review the literature to determine if such claims are true.

⇒

CHO hydrogel compound

⇒

Control condition

⇒

Prolonged exercise (>1 hr)

⇒

Well-trained + trained + recreational athletes

⇒

Commercially available gel

The outcome variables included exercise performance, CHO oxidation, Exogenous CHO oxidation, whole-body substrate oxidation, blood glucose, VO2, exercise economy and GI comfort/distress. The exclusion criteria for this search included:

⇒

Less than 1h in duration

⇒

CHO mouth rinse

⇒

Review articles and case studies

Relative reported contributions to total fuel use differ between the studies when using MD+F hydrogels, however, when cycling at 50%Wmax and during low-intensity cycling, no difference was seen in performance compared to normal CHO gel consumption.

Although some studies showed a trend for greater comfort of GI following hydrogel consumption compared to normal CHO gel consumption, none of these results were considered significant. So far, data does not support the claimed benefits of enhanced CHO delivery to the muscle, reduced GI distress, and better performance when compared to traditional CHO solutions.

Following the above criteria’s, the search resulted in six studies.

Practical Takeaways 

Overall, studies fail to show any additional benefits of consuming MD+F hydrogels over normal gels in terms of muscle oxidation of exogenous CHO, GI comfort, or performance. This being the case, practitioners should consider purchasing normal CHO gels over normal hydrogels for their athletes.



Irrespective of hydrogel use or not, the literature agrees that muscle glycogen response to CHO ingestion is dose-dependent, therefore, the more CHO consumed the more fuel that will be available for exercise performance. CHO intake should follow a sliding scale of 3-8 g.kg-1 body mass per day depending on sport and training/competition demands.



Increased CHO exposure causes a ‘gut training’ effect (see article below) which will help with enhanced GI tolerance of ingested CHO during exercise. Therefore, practice this process during training before any competition.



CHO consumption timing can influence improved CHO oxidation, with better outcomes associated with consuming CHO sources every 20 min compared with 5 min intervals.

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James’ Comments “This is a very timely review article considering the media attention that hydrogels have recently received in athletic and research circles. On the whole, it appears that the scientific research supporting these products is limited and equivocal at present.

The authors do highlight that only six articles were reviewed during this paper and so more research is definitely needed to assess the efficacy of hydrogel technology moving forward.

However, one thing we can be confident on is the efficacy of CHO to fuel performance (see podcast below with Professor James Morton), and with this in mind, I would encourage practitioners to focus on fuelling strategies that will allow athletes to consume the recommended 60-90g of CHO per hour of exercise. A simple example could be a bottle of Lucozade, one medium-sized ripe banana, and one CHO gel.”

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Injury Prevention & Rehab

30

Injury Prevention & Rehab This month’s top research on injury prevention and rehabilitation.

CAN INTERNAL LOAD MARKERS PREDICT NON-

CONTACT INJURIES IN PROFESSIONAL BASKETBALL? Ferioli, D. et al. (2020) Research in Sports Medicine.

WHAT ARE THE EFFECTS OF STATIC STRETCHING ON MUSCULOTENDINOUS PROPERTIES IN HAMSTRING MUSCULATURE? Riccetti, M. et al. (2020) Sports.

WHAT ARE THE MAJOR INJURY PATTERNS SEEN IN PROFESSIONAL FOOTBALL? Klein, C. et al. (2020) British Journal of Sports Medicine.

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Injury Prevention & Rehab

31

[Abstract]

Can internal load markers predict non-contact injuries in professional basketball?

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Monitoring load is important in the athletic population, as both overload and underload can potentially result in injury. For example, a rapid and excessive spike in training load during a competitive season often yields negative effects like neuromuscular fatigue which could lead to injury. The acute to chronic workload ratio (ACWR), as well as a rating of perceived exertion (RPE), are measures that are used to monitor overall training load and can be useful to track an athlete over time to ensure they aren’t being predisposed to injury.

Thirty-five basketball players from three different Italian teams were monitored during two competitive seasons from 2015-2017. Each season was split into three periods: preparation period, championship tournament period, and play-off period. Athlete internal load was assessed by session-RPE 30 min following each training session and match.



A total of 95 time-loss non-contact injuries were sustained over the two seasons with 16 occurring in the preparation period, 74 during the championship tournament period, and 5 during the play-off tournament period.



Non-contact injury incidence was 4.7/1000h

The purpose of this study was to determine the association between load markers and the occurrence of non-contact injuries in basketball.

The mean weekly RPE was calculated and used as an indicator of the week’s intensity, as well as the total exposure. The absolute week-to-week change and cumulative loads were calculated for two, three, and four weeks. Non-contact injuries sustained throughout the two seasons were collected and injury incidence was calculated per 1000h of basketball.

for the preparation period, 4.8/1000h for the championship tournament period, and 5.8/1000 h for the play-off tournament period.



each period were as follows: preparation period = 4331, championship tournament period = 3464, play-off tournament period = 3385.



Practical Takeaways 

Monitoring load is important when working with athletes, however, the nature of non-contact injuries is multifactorial so additional measures including previous injury history, strength, flexibility, and neuromuscular control should be assessed.

Additionally, it is important to not overlook the basics making sure athletes are getting at least 8h of sleep per night and drinking at least half of their body weight in ounces of water per day.



Session-RPE is a simple and effective tool to monitor internal load in basketball 30 min after a training session or game. This will provide information about the session's internal loads.



S&C coaches should consider what seasonal phase an athlete is in when sustaining a non-contact injury to further be able to address and modify training programmes and loads. Making sure an athlete’s resistance training frequency is 4-5 times a week in the preparatory period and 1-2 times a week in the competitive period is a good place to start.

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The average weekly load sustained during

There was no association between any load marker and non-contact injuries, as accordingly, load markers showed no injury predictive ability.

Jordan’s Comments “We simply cannot predict or prevent injuries from happening. As a physical therapist and S&C coach, my goal is to try and replicate the demands of each athlete’s sport as best as possible towards the late stages of rehabilitation or focus on measures to address common injuries seen in specific sports.

Athletes' volume of training is normally increased during a preparatory period compared to a competitive period, so monitoring load during these phases is important to help decrease the risk of injury.

Previous injury history wasn’t considered in this study though, which is crucial when assessing an athlete, as this could have potentially skewed the results.”

Injury Prevention & Rehab

32

[Abstract]

What are the effects of static stretching on musculotendinous properties in hamstring musculature?

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Static stretching is a common exercise performed to help improve flexibility. Research though has shown there are potential negative effects due to static stretching including decreases in performance (see HERE). The acute effects of static stretching are dependent on many factors, such as intrinsic stiffness of the musculotendinous system, which is influenced by the muscle-tendon length.

Twelve track and field and team-sports athletes underwent a stretching procedure which included five sets of 30-sec stretching with a 30-sec rest to the biceps femoris and semitendinosus hamstring muscles. Additional testing which included a single passive stretch to evaluate musculotendinous junction (MTJ) displacement, passive torque, followed by two maximal voluntary isometric contractions of the hamstring muscles (5-sec with 15-sec rest) in a neutral position (90° flexion) were conducted 2 min before and immediately after the stretching procedure.



After 2 min rest, a single passive stretch was performed using a dynamometer in a passive mode so there was no active contraction of the hamstring musculature. This was performed over the determined passive range of motion (PROM) to evaluate passive torque and MTJ displacements.

During this period, peak maximal voluntary isometric torque (MVIT), as well as passive torque, were measured.



Passive torque decreased after stretching.



MTJ displacement was greater for semitendinosus

The aim of this study was to investigate the acute effects of static stretching on the semitendinosus and biceps femoris hamstring muscles.

Values for MVIT were 17.6% for biceps femoris and 18.6% for semitendinosus.



Values for passive torque changes were 34.1% for biceps femoris and 27.9% for semitendinosus.



Values for MTJ displacement were 19.3% for both biceps femoris and semitendinosus MVIT decreased immediately after stretching.

muscle than biceps femoris muscle prior to the testing procedures.



No difference was observed between muscles after the stretching procedure, however, changes between before and after the testing period were significantly different, where greater changes in MVIT, passive torque and MTJ displacement were observed for biceps femoris muscle than semitendinosus muscle.

Practical Takeaways 





The semitendinosus has a longer fascicle length and tendon than the long head of the bicep femoris which is important to consider for practitioners, as the longer the tendinous tissue, the greater lengthening it can undergo which impacts MTJ displacement the greatest after a single stretch.

The long head of the biceps femoris is often predisposed to injury due to its very short fascicles compared to the semitendinosus. Therefore, exercises like the Nordic hamstring exercise performed as 3 sets of 6-8 reps once per week in both the rehabilitation and S&C setting can be helpful for reducing injury risk.

Force losses that occur after static stretching are dose-dependent, so S&C coaches should be cautious when prescribing static stretching in order to optimise the balance between flexibility improvements to avoid force loses. Longer rest periods should be implemented when prescribing static stretching immediately preceding a power development exercise like a vertical jump.

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Jordan’s Comments “Static stretching does improve flexibility; however, it is important to consider each muscles anatomy as additional factors impact the positive effects seen after static stretching. We know that the increases seen in flexibility are most likely due to neurophysiological mechanisms and improvement in the tolerance to stretch over time.

Static stretching is often included in the rehabilitation setting and in my clinical practice, I include static stretching however I put more of an emphasis on active rather than passive approaches. Since this study only included a very small sample size, future studies should look at the effects of static stretching on a larger population across multiple sports.”

Injury Prevention & Rehab

33

[Abstract]

What are the major injury patterns seen in professional football?

OBJECTIVE

WHAT THEY DID

WHAT THEY FOUND

Injury occurrence via video analysis can provide a detailed presentation of biomechanical changes that occur leading up to an injury. This can be beneficial in developing rehabilitation and injury risk reduction programming to target specific joints and muscles.

Male football players from two professional German clubs were monitored for injuries via video analysis during three consecutive seasons (2014-2017). Injury mechanisms were differentiated into three main categories 1) contact injuries, 2) indirect contact injuries, and 3) non-contact injuries. During this time, data for each injury was collected which included the general match and player information, location of the injury, game situation, player/ opponent behaviour, injury mechanism, and injured body location.

The top five typical injury patterns that led to moderate and severe injuries:

The purpose of this study was to analyse the most common injuries seen in professional football and determine the mechanism of injury using video analysis.

After each of the three seasons, the lead researcher reviewed the match injuries which were deemed moderate and severe in severity. Each video sequence contained approximately 10-15 sec before and approximately 5-10 sec after the injury event.

Typical injury patterns seen were described for all body locations.

1.

The head-to-head injury (e.g. concussion, fracture).

2.

The collision-and-fall shoulder injury (e.g. dislocation of glenohumeral/acromioclavicular joint).

3.

The sprinters thigh injury (e.g. muscle tear of anterior thigh, posterior or adductor muscle).

4.

The perturbation-and-strain thigh injury (e.g. muscle tear of anterior thigh, posterior or adductor muscle).

5.

The collision-and-twist ankle injury (e.g. sprains, partial or full tear of medial or lateral ligaments).

Most of the identified injuries affected the knee (24.3%), thigh (23.5%), or ankle (19.1%) followed by the shoulder (8.4%), and head (7.8%).

Of the injured players, 4.3% were goal-keepers, 39.7% were defenders, 41.4% were midfielders and 14.5% were forwards.

Almost half of the analysed injuries were contact injuries (49.3%), whereas 23.2% were classified as non-contact injuries, and the remaining 27.5% were indirect-contact injuries.

Practical Takeaways 

Physical therapists should implement rehabilitation scenarios that mimic match situations to the best of their ability, as almost half of all injuries were contact injuries. This can be done by using physio balls to mimic contact scenarios as wellperforming exercises in an open environment. This could include performing sports specific exercises on a playing field with other athletes and noise present.

⇒ Physical therapists and S&C coaches should develop and implement programming to include high-speed running and sprinting as well as balance training which can be beneficial for injury risk reduction as the knee, thigh and ankle are often affected in both contact and non-contact injuries 

Having video footage of typical injury patterns is beneficial for practitioners to assist with identifying non-contact injuries in order to teach athletes proper positioning of the hip, knee, and ankle when completing match-specific movements.

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Jordan’s Comments “Due to the complexity of injuries and their occurrence, it is important to know the main body parts and injuries sustained in a given sport, as this can provide valuable information for injury risk reduction. When athletes come in for treatment after sustaining an injury during a game, I always ask to see if the injury was captured on video. This can provide me with information pertaining to the exact mechanism of the injury which is helpful to know prior to the physical assessment.

One main limitation of this study was if the injury wasn’t immediately game-ending, athletes continued to play. This could have skewed the overall data if an initial injury was worsened as a result, or it could have pre-disposed an athlete to another injury to another body part.”

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Ask the other coaches in the group If you don’t challenge yourself cognitively and emotionally, you want to grow and achieve your coaching goals, you’ll just stay as you are. #growthmindset

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