The Latest Research

The latest edition of the IAAF’s New Studies in Athletics technical journal has been released. Among many excellent studies included in this edition is an article written by South Australian coach, Dylan Hicks. The article explores the effectiveness of resisted sprint training and assisted sprint training and we are delighted to include a summary of his research.

Resisted and Assisted Sprint Training: Determining the Transfer to Maximal Sprinting

Abstract

Resisted sprint training (RST) and assisted sprint training (AST) are methods used to overload the neuromuscular and physiological systems with the aim of causing adaptations that transfer to ‘free’ maximal sprinting (MS). This review of more than 50 publications summarises teh effects of RST and AST with the aim of assisting coaches to understand their application.

RST has been shown to promote kinematic changes that emphasise propulsive force application in MS. RST using pulled sled loads of 10-30% bdoy mass also appears to be effective in improving acceleration abilities while loads greater than 30% of body mass appear to disrupt acceleration mechanics.

AST using a horizontal towing mechanism over distances between 20-60m enhances acute maximal horizontal velocity. Across most reviewed studies, AST with towing or downhill running increases stride length while ground contact time decreases. Stride frequency, however, decreases or remains unchanged. This suggests that AST may not provide any greater transfer than a standard maximal sprinting protocol, but due to the inconsistencies in the research it should be left to the practioner to determine whether AST is suitable.

Full article available for New Studies in Athletics subscribers.

“Resisted and assisted sprint training interventions appear to have the greatest transfer to maximal sprinting when performed bi-weekly across one or more training cycles of four to eight weeks”

“Assisted sprint training is a training method that should be restricted to advanced athletes who have the requisite strength to cope with higher than voluntary velocities”

Contrast Training

Hicks also suggests that the use of a combination of RST, AST and MS within the same session may be an effective strategy for enhancing motor patterrns and improving maximal speed. There is some evidence to suggest that the most effective composition of contrast training is to conduct the RST and AST first, followed by free sprinting (Wagganer, Williams & Barnes, 2014).

“This might be a reminder that static stretching isn’t the devil it’s been made out to be”

No Effect of Muscle Stretching within a Full Dynamic Warm-up on Athletic Performance

Tony Blazevich from Edith Cowan University, whose research on the aerobic capacity of children was featured in Athletics Coach - 2 / 2018, has now teamed up with a range of international sports researchers to investigate the effects of static and dynamic stretching routines on flexibility, sprinting and jumping performance.

Their findings have recently been published by the American College of SportsMedicine and he has very kindly shared a summary of the key findings with AccreditedAthletics Coaches.

Abstract

Purpose: This study aimed to examine the effects of static and dynamic stretching routines performed as part of a comprehensive warm-up on flexibility and sprint running, jumping, and change of direction tests in team sport athletes.

Methods: A randomized, controlled, crossover study design with experimenter blinding was conducted. On separate days, 20 male team sport athletes completed a comprehensive warm-up routine. After a low-intensity warm-up, a 5-s static stretch (5S), a 30-s static stretch (30S; 3 10-s stretches), a 5-repetition (per muscle group) dynamic stretch (DYN), or a no-stretch (NS) protocol was completed; stretches were done on seven lower body and two upper body regions. This was followed by test-specific practice progressing to maximum intensity. A comprehensive test battery assessing intervention effect expectations as well as flexibility, vertical jump, sprint running, and change of direction outcomes was then completed in a random order.

Results: There were no effects of stretch condition on test performances. Before the study, 18/20 participants nominated DYN as the most likely to improve performance and 15/20 nominated NS as least likely. Immediately before testing, NS was rated less ‘‘effective’’ (4.0 T 2.2 on a 10-point scale) than 5S, 30S, and DYN (5.3–6.4). Nonetheless, these ratings were not related to test performances. Conclusion: Participants felt they were more likely to perform well when stretching was performed as part of the warm-up, irrespective of stretch type. However, no effect of muscle stretching was observed on flexibility and physical function compared with no stretching. On the basis of the current evidence, the inclusion of short durations of either static or dynamic stretching is unlikely to affect sprint running, jumping, or change of direction performance when performed as part of a comprehensive physical preparation routine.

Purchase the full study online.

Training Volume, Not Frequency, Indicative of Maximal Strength Adaptations to Resistance Training

“The primary finding was that 6 weeks of resistance training led to significant increases in maximal strength and fat-free mass. In addition, it seems that increased training frequency does not lead to additional strength improvements when volume and intensity are equated. High-frequency (6× per week) resistance training does not seem to offer additional strength and hypertrophy benefits over lower frequency (3× per week) when volume and intensity are equated. Coaches and practitioners can therefore expect similar increases in strength and lean body mass with both 3 and 6 weekly sessions.”

In Athletics Coach - 2 / 2018, we shared a weekly training program used by sprints coach Glen Mills, which resulted in some coaches expressing surprise at the infrequency of his gym sessions. A recent study published in the Journal of Strength and Conditioning Research may offer an explanation of his rationale, with higherfrequency training resulting in no signficant improvements in stregnth or hypertrophy benefits comapred with lower frequency training when intensity is equated.

Read the full study for free online

“The manipulation of training volume and intensity must be systematic, stimulating continued physical adaptions through progressive overload whilst guarding against maladaptive training outcomes such as non-functional overreaching and overuse injury through the integration of sufficient recovery”

Understanding the Relationship Between Coach and Athlete Perceptions of Training Intensity in Youth Sport

A recent study published in the Journal of Strength and Conditioning Research has highlighted the prevelance of mismatches between the coach’s intended training session intensity and the perceived intensity by the athlete. Of the coaches and athletes studied by Scantlebury et al. (2018), coaches tended to overestimate the intensity of sessions designed to be ‘high intensity’ whereas they tended to underestimate the intensity of sessions intended to be ‘low intensity’.

This mismatch between the intended intensity and actual intensity results in coaches prescribing ‘high intensity’ sessions that do not provide a sufficient training stimulus to achieve the desired adaptation and ‘low intensity’ sessions which resulted in excessive load on the athlete, hampering their recovery and predisposing the athlete to over-use injuries.

The authors of the study suggest that coaches implement ongoing athlete surveys,asking the athletes to grade a sessions intensity between 1 and 5 to ensure that thecoach’s intended training intensity is aligning with reality.

Purchase the full study online.

A Comparison of the Effects of Short-Term Plyometric and Resistance Training on Lower- Body Muscular Performance

The evidence examining the effectiveness of plyometric training for athletics coaches continues to build, and this latest study by Whitehead et al. (2018) helps coaches to understand the most effective training methods for a given performance parameter.

The study tested 30 male athletes who were distributed to either a plyometric training program, a resistance training program or a control group who did not participate in any training. Training was twice per week over an eight week period. Pre- and post-intervention tests were performed on the participant’s 20m sprint time, standing long jump, vertical jump, 1RM back squat and agility test.

After the training intervention, athletes in the plyometric training group significantly improved their vertical jump and 1RM back squat, with a “likely improvement” in their standing long jump performance. However, neither the plyometric training group nor the resistance training group improved their 20 metre sprint time, conflicting with previous studies that have shown both training interventions may improve an athlete’s speed. This may be explained by the frequency / intensity of training being inadequate or by the focus on ‘vertical plyometric’ activities, rather than activities that focus more on a horizontal generation of force.

The authors conclude that “Plyometric training programs similar in duration and intensity to the one used in the current study should result in an improvement in body composition and vertical jump. Both plyometric and resistance training appear to result in improvements in lower-body muscular performance in untrained men. More specifically, there are equal increases in standing long jumping ability and maximal strength. What this means is that decisions can be effectively made regarding time spent in an individual training mode based on the individual needs of the athlete, equipment, and facility limitations.”

“Like any other training component, plyometrics need to be considered within the context of the overall program.”

Read the full study for free online.