Track This: The Overlooked Piece of Training

Effects of Track This: The Sleep Tracking Overlooked Piece forof Athletes Training AN ANALYSIS OF HOW TECHNOLOGY IS IMPROVING THE WAY ATHLETES RECOVER

MELANIE ABBOTT

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If you’re an athlete looking for ways to improve your performance it may not be more training that is going to help you. This book will outline how getting more sleep may be the best way to reach the next level. I acknowledge that your life is busy and simply “getting more sleep” is not a realistic solution to your tiredness. This book goes beyond focusing on quantity of sleep and instead why you should be intentional with the time you have in bed and place an emphasis on recovery. This book will delve into what sleep metrics matter and the most accurate way to track your sleep based on research and expert sources. The devices and brands analyzed were chosen because of their popularity and prevalence among elite and amuetur athletes and are examined as objectively as possible with expert opinions and athlete testimonials to back them up. I am not affiliated with any fitness company and I am not a sleep doctor trying to promote my practice. I am a college triathlete who knows all too well effects of sleep deprivation, poor recovery, and fatigue-caused overuse injuries. My experience is not uncommon; I am the story of highschool and college athletes across the United States who practice multiples times a day, everyday, who wake up early for practice and stay up late to finish school work, who show up to every practice no matter how fatigued, who make training their highest priority but no take little regard for recovery. The mentality in athletics needs to shift from quantity to quality. My goal is to stress to you, fellow athletes, the importance of recovery and provide you with the tools to practice healthy sleeping habits.

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INTRO TRACKING DATA TESTIMONIALS PERFORM CONCLUSION

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Photo by Pexels

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IMPORTANT This chart breaks down sleep jargon that will help you navigate the studies, findings and data included in this book.

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INTRODUCTION

Don’t Sleep On This

Imagine doing the same thing every single day since the day you were born and contribute nearly one third of your day to it, yet take no care to learn about how to optimize your performance at it. People spend countless hours researching, practicing, learning and mastering skills for their profession, education, sports and hobbies but overlook the activity that they not only spend the most time doing, but the one that allows them to function and perform daily tasks.

The activity described is sleep. It is not revolutionary information that it is important to get a good night’s rest. Countless research has also proved sleeping allows the body to reset and recover both physiologically and psychologically for the next day. This is especially applicable to athletes since they are pushing the physical bounds of their bodies everyday.

Countless research reaching similar conclusions, shows that sleep is important to athletes’ performance so they recover well enough to peak when it matters most. This is because the hormone attributed to growth and repair is released by the pituitary gland in the endocrine system which can only be released when the non-rapid eye movement (NREM) sleep stage is reached.2

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However, the lifestyles that many athletes balance with school, work, multiple early morning and late night practices, and long compitions can make this rather challenging. These obstacles along with other societal factors is why according to a 2012 Gallup Sleep Poll, Americans are sleeping an average of one hour and 6 minutes less than they were 50 years ago.8 Consequently, this is why tracking sleep has become more relevant in today’s society more than ever.

Athletes are told to get “good sleep,� but what does this mean? The quantity of sleep is one way to determine this, but the quality of sleep is a more precise way to analyze it. According to a review from British Open Sport and Exercise Medicene, good sleep quality is achieved when a person is sleeping 85% of the time they spend in bed, they fall asleep within 30 minutes or less once lying down for bed, waking up no more than one time in the night, and being awake 20 minutes or less after initially asleep.1 Sleep quality is just one of the many metrics necessary to assess how to reach optimal sleep efficiency and recovery. These metrics as well as the ways these metrics are monitored and logged will be examined and explained in detail in the following pages.

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Importance of Sleep Not getting enough sleep is more detrimental than simply feeling tired.

Getting adequate sleep requires consistent practice and can not be saved up in a “sleep bank” or caught up after you have had a night of 3 poor sleep.

Sleep can cause irreversible damage to a person’s body, and it is not always obvious to detect. The human body tries to compensate for a lack of sleep by working in overdrive so someone does not feel the effects.3 This is why sleep should not be solely based on feel and self analysis because the body lies to the mind.

Sleep affects the brain psychologically by blurring the central processing system and hindering the mind’s decision making and focusing capabilities. According to the Journal of Science and Medicene in Sport, “the concept of sleep-dependent brain plasticity reinforces the importances of sleep in elite athletes by its effects on the consolidation of

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motor skills learning.”3 If the brain is fogged from making clear decisions to function in daily life, the brain will not be decisive enough to make sport specific judgements. This is called neurological maladaptation.

1 Since sleep is the only time the body can grow and repair, missing out on this time results in physiological maladaptations. Research shows a lack of sleep leads to decreased speed and anaerobic power and increases an athletes’ risk of illness and injury.1

The first step to creating healthy sleeping habits is by coaches and sport staff initiating recovery centered conversations. By starting the conversation, athletes will begin to adjust their mindset about recovery.

“To ameliorate these sleep concerns, behavioral sleep education and sleep hygiene strategies have been shown to be beneficial.” 6 The specific effects sleep has on sport performance will be examined in further detail throughout the book, but this is to establish an understanding for the need of optimized sleep.

Marisa Fraizer Missouri State Exercise Science Graduate

Marisa Fraizer has years of personal and educational experience with sleep research.

An athlete herself, Marisa ran Cross Country and track for two years at St. Louis University before transferring to swim and study exercise science at Missouri State University. She now coaches the Drury Women’s Triathlon Team.

Everytimes something stressful happens, it releases cortisol which is an important hormone for getting your body to respond to a threat or exert energy. But sleep deprivation does the same thing. It tells your body that you’re in a state of stress and you release more cortisol than your body can handle. This constant stress hormone means your body never fully recovers.

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This is an image from a research sleep lab where PSG tests are conducted.

Journaling is one of the methods to record sleep data.

Photo from Pexels

Photo from Pexels

This athlete is using a Garmin watch to track her training and sleep.

Photo from Pexels

How Is Sleep Data Tracked?

Researchers have been collecting data from sleep for more than 50 years, but with new technological advancements it can be challenging to determine which method is the most accurate, practical, cost effective and beneficial.

Not only are Americans sleeping less than ever before, athletics are becoming more demanding and serious at the youth level. Due to the rise in NCAA sports and youth performance teams, athletes are facing the pressures and arduous training regimines at younger ages. Tracking

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sleep and recovery used to be targeted towards professional and Olympic athletes, and most research uses elite adult athletes as the focus group.

However, the sport culture in today’s society warrants sleep tracking, a necessary action for athletes at all levels in order to train in a healthy and sustainable way. This is why wearable tracking devices on the market have mainstreamed sleep tracking for everyone. Is the data these devices produce trustworthy?

Historically, sleep polls are used to collect data from large groups. Large data sets do not yield more accurate results. “The most commonly used method are subjective sleep questionnaires; however, these have been shown to have a poor relationship with objective measures of sleep, therefore questioning their efficacy.”4 There is no way to delineate in the data from people who are completely honest and those who are not. Also, the best analytics to track cannot be determined from self-reflection, they can only be cultivated with the use of technology.

Methods athletes use to track sleep falls into three categories: manually tracking via journal, polysomnography and actigraphy.

Photo from Pexels.com

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Manual Sleep Tracking Hot or not?

While bullet journals are all the rage, your sleep is not worth sacrificing for aestetics. If journaling is a trend you want to take up, make it an addition to ways your manage your sleep. Avoid relying on it as the sole way to track it.

Research Says...

Manual sleep tracking refers to logging sleep data without the aid of any devices. This is considered the old school method. The way users of the method record data is through a written log that must be updated daily before bed and after waking. Aside from the commitment it takes to religiously log data multiple times a day, the metrics that are able to be recorded is limited.

Manual analytics includes bedtime and wake time, time in bed, and time awake and perceived recovery. Sleep latency and time asleep are two of biggest metrics that cannot be recorded from this method as well any form of recovery score.

In order to manually record recovery, a person must take their resting heart rate each morning after waking consistently in order to establish a norm and then any increase in the rate denotes a lack of full recovery.

Research supports that sleep logs are not a reliable or an objective source because in order to fully hit proper circadian rhythms 24 hour monitoring is required to find accurate sleep-wake cycles.2

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The

PSG

The method of cultivating data sleep analysts have coined as the golden standard is polysomnography (PSG).

According to Journal of Sport Sciences, this is the best way to assess sleep because it is in touch with the neurons in a person’s brain.2 PSG is an expensive test using electrodes in a sleep lab and collects epochs non-stop.

Golden

Standard

Disadvantages of Polysomnography PSG is not a practical way for people to get a realistic understanding of their sleep because of the number of variables that come with the sleep study being performed in a lab. Research shows that when athletes travel and sleep in a hotel or change their normal sleep habits, sleep is disrupted 3 and will be abnormal.

Therefore any research from PSG may not be an accurate depiction of that person’s typical sleep patterns. In addition, circadian rhythms can take weeks to be detected and perfected, so one, or even a few, nights at a sleep lab will not elicit these results.2 PSG is also not accessible enough to become the mainstream method society is seeking. “PSG is expensive, it can be invasive for participants, 3 is to collect data simultaneously with multiple and it is impractical if the aim participants over consecutive nights. Activity monitors have emerged as a potential alternative to PSG for monitoring sleep for athletes.”3 While PSG is not practical for prescribing weaknesses in sleep, it is very useful for research. This is because it is proven to produce accurate data points, so PSG can be used as a control against testing wearable tracking devices.

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ACTIGRAPHY A 14

Cleveland Cavaliers NBA Player Mathew Dellavedova wears the WHOOP monitor during a game. He wore it for 15 games before the NBA banned the monitor during games and fined Dellavedova.

Photo by Wearable.com

This is the most common way athletes track sleep.

Actigraphy is the scientific way to define wearable sleep devices. Actigraphy is the most accessible and cost effective way to track sleep.5 “Wristwatch actigrapy is a non-intrusive, cost-effective tool used to estimate sleep quantity and quality which has been compared to PSG, showing an accuracy of up to 80 percent in sleep disordered patients for total sleep time and sleep efficiency.” 3 That study was conducted using the Philips Actiwatch in 2012 and since then the accuracy to PSG has been refined to be even more exact.

In a 2016 study, research showed that activity monitors’ sleep detection is within 91-96 percent of PSG.5 However, the metric that is the most inaccurate and fluctuates across actigraphy wearable brands is the ability to detect wake time. In the 2012 study, it was especially low and only within 38-54 percent of PSG. This is seen in watches that have many fitness capabilities and sleep is just one of its many uses. However, sleep specific watches use several different actigraphy sensors which makes it within the 95 percentile in similarity.7 The reason why this technology is on par with PSG is because epoches are collected every minute. While

comparing actigraphy to PSG shows confidence in the technologies’ capabilities, that still does not confirm its effectiveness for athletes.

Testimonials of user experience confirm this, but research has not fully proved this. “No normative data exists for athletes, making comparisons with untrained populations problematic due to the largely unknown effect of exercise training on sleep.”3

This is an example of the data from a Garmin Forerunner 720XT watch after a night’s rest. This was provided by Nic Lauxman, a triathlete for the University of Missouri.

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Accuracy of Actigraphy This research study was conducted at the Australian Institute of Sport by the Human Research Ethics Committee and consists of 16 endurance elite cyclists with an average age of 19. The cyclists participated in the study during a six week training camp during their season. They used PSG and activity monitors simultaneously. The activity monitor used was the Philips Respironics Nano.5

Polysomnography

Sleep Duration

Wake After Sleep Onset

Actigraphy

Sleep Effciency

Sleep Latency

41 8.5

18.3

80 7.5

89.6

89%

51%

95%

Hours

Minutes

Percentage

85.2

95%

17.3

Minutes

This data shows the accuracy of the wearable device since it ranks in the between the 89 and 95 percent accurate to the PSG data. Even though wake after sleep onset is only in the 51 percentile, that is because at the time of this study, 2012, the actigraphy technology had not yet developed enough to properly detect wake and movement during sleep. This is because it had a difficult time distinguishing between sleep onset and when the device wearer was laying in bed awake. Since then, the technology has developed so it is also now in the 90 percentile of accuracy. 9

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Importance of Coach Fac This study consists of 35 coaches and 51 support staff personnel. It was conducted by the Australian Institute of Sport. The coaches and staff represent 12 team sports at either the professional or international level. Coaches and personnel completed the sleep beliefs scale for a three month period.3

Coaches reported that their athletes are primarily recording sleep data through a diary. After looking at this data, one hypothesis formed for the 75 percent of athletes self logging rather than using wearable devices (21 percent) would be the expenses affiliated with the devices. However, considering that all of the athletes are at the elite level, it is less likely that is a leading factor. It is also not probable that the lack of actigraphy use is due to availability of the technology since this study was published in December,

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cilitated Sleep Education 2018 and many devices would have already been on the market. This makes the most plausible reason for the lack of technology use due to the education athletes received from personnel about sleep.

This graph shows that the questions personnel polled their athletes on are all sleep habits that athletes can control. None of the questions require technology to answer the questionaire. While it is beneficial to the athletes’ sleep and performance for coaches to encourage them to practice sleep sleep habits, the questionnaire is not able to accurately assess the athletes’ sleep quality or recovery score. It is also important to note that while this data shows the percentage of coaches who monitor these habits, it does not portray how well athletes are able to follow these habits.

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Periodization Effec Sports that are endurance or aerobic based such as swimming or running implement periodization in their training to create varying intensity cycles. This allows periods of rest with in the season around competitions in order to reach a state of maximum performance. This study was conducted on seven female national level swimmers with a mean age of 19 throughout an entire season (March-August) to study the effects of their training load and sleep quality. This study was conducted in a lab with PSG and each swimmer spent three nights in the lab during each training phase. Sleep epochs were collected every 20 seconds and the athletes followed their normal sleep and wake times. During the entire training season, the swimmers kept a log indicating waking heart rate, training volume, and sleep habits.â ś

Quality of Sleep During Training Cycles Onset

Time in Bed

Total Sleep TIme

Peak

Sleep Onset Latency

Sleep Metric

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Taper

REM Onset Latency

Wake After Sleep Onset

cts on Sleep Quality While athletes may strive to get the same amount of sleep no matter what stage of training they are in, this study shows training load affects duration of sleep and quality. It is logical that sleep duration was higher in the onset and peak training periods because more stress to the body warranted more sleep time. However, the lowest number of movements were recorded during the taper season. There was also a significant increase in stages one and two of REM sleep, which is deep sleep compared to the heavy training periods. This shows how a high training load disrupts the body getting from optimal sleep. For sports that rely on periodization, this shows that too much time spent in onset or peak training cycles could lead to overtraining syndrome.

Photo from Pexels.com

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Athletes

Sleep Diffe Non-Athletes

These graphs illustrate that even though athletes are spending more time in bed than their non athlete control, they are waking up more and experiencing more disturbances. The speed skaters, which is the most cardiovascular and aerobic sport examined had the least efficient sleep. This shows that it is plausible that strenous excercise inhibits sleep.

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*This study is was conducted by the French Institute of Sport in their research titled The Variability of Sleep Amoung Elite Athletes.

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erentiation

This graph illustrates the percentage of sleep where movement was detected. This metric can not be self tracked since the movement was detected during sleep. The athletes experienced restlessness and movement far more than the control. While the athletes have a higher ratio of movement, their numbers are still far lower than a person who is diagnosed with a sleep disorder.

This shows that excercise disturbs sleep quality. Since high intinsity training disrupts sleep, athletes can minimize movement by avioding excercise two hours before bedtime and cooling down after training sessions.

This shows that it took athletes more than three times as long to fall asleep compared to the control group. Habits that decrease sleep latency include eating sleep promoting foods such as bananas or chamomile, creating a bedtime routine, and abstaining from screen use one hour before bed.

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Which Company Was First?

2012

Philips Nano

2013

Fitbit Flex

2015

WHOOP 1.0 device

2016

Oura Ring first edition

2018

Garmin Advanced Sleep Metrics *previously only made sleep reccomendations

2019

Huawei Honor Band 5 A 24

*not available in many countries

based off of heart rate

What’s the Big WHOOP? Their first monitor debuted in 2015, their latest version WHOOP 3.0 was released May 2019

NEW!

WHOOP is a subscription service with a 6 month minimum startup, costing $30 each month. The device is included in this fee.

WHOOP is within one breath per minute of PSG

WHOOP is within one beat per minute of an EKG

Worn by every player in the NFL, NBA teams, MLB players, Olympians, Professional Crossfitters, NCAA athletes

What does it do?

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Sleep Quality: Time spent in light, REM, deep, awake

Efficiency: Number of disturbances per night Consitancy: Recomends sleep & wake times

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Recovery 3 zones: red, yellow, green Combination of heart rate and sleep performance

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Did you know?

Strain

WHOOP users have been able to detect symptoms of COVID-19 earlier than non users because of the respitory rate metric. They can tell symptoms from the rate variability sonner than physical symptoms are present. *Information via WHOOP.com

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Photo from Pexels.com

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TESTIMONIALS

ATHLETE

KIMI REED

Kimi Reed an olympic trials marathon runner in Springfield, Missouri who graduated to longer distances after earning All-American ranks at the division one level for cross country and track. She is ranked in the top 10 percent of marathon runners in the U.S. Within the past two years, I started using this app called training peaks.

It kicks out those numbers about fitness, fatigue and form. I kinda know where my fatigue should be and it tells you if you are at risk for injury. I don’t go by that 100 percent. I basically go off of that and how I feel in general. I try to make sure I get at least eight and a half to nine hours of sleep every night. Honestly, if I can remember my dreams I know I didn’t get into a very restful sleep. Garmins weren’t really a thing until I got into college.

All through highschool it was just training with a wristwatch and trusted the coach when he said ‘this route is four miles go run this route.’ I think I started going based on feel and I really liked that but I still am a numbers person. I think part of why I don’t use more technology is because it just wasn’t there. I’ve just always gone on feel and trusted what my college or highschool coaches have told me to do for recovery. If I am dreading going out there, then I know I am probobly not recovered enough from my last marathon. I would advise someone to take their recovery days easy and that’s okay. Part of my issue is that once I got my Garmin I would realize ‘oh well i ran this route in this time and pace last time.’ Most athletes have a pretty competitive nature and I found myself just being too competitive with the Garmin, so I found myself just having to physically not let myself run faster than certain places on easy days.

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SETH BAILEY Seth Bailey is a sophomore swimmer for the University of Tennessee and is an SEC finalist and Olympic Trials qualifier. He started using WHOOP once he started attending the university in 2018.

The WHOOP takes into consideration a lot of things that we aren’t able to notice like the feature that tells you how many disturbances you have while sleeping. Some nights it will tell me that I had 16 disturbances and I feel like I didn’t have one disturbance. It’s very interesting to see what WHOOP says compared to how you experience it.

Swimming is a sport that relies heavily on your recovery to determine how well you can perform the next day. There are alot of sports where they have one game and then the next one is the next week or two days later. Swimming is where our championship meets are legit like a week long back to back days so recovery is really important between those sessions. Being able to be on top of your recovery is a big advantage in the swimming world.

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KATE McCARVILLE Kate McCarville swims for Sprinfield Aquatics Swim Team in Springfield, Missouri. She is currently a junior in high school and plans to swim for the University of Tennesee.

She has three Olympic Trials qualifying times

WHOOP is so brutally honest with you. Overall, it’s made me be alot more reflective on what I’m doing with my sleep and alot more honest with myself too. I can improve my sleep because the more you have, the better your performance is going to be.

The recovery score can either be red, yellow or green. If I have multiple days in the red [my coach] Thomas will ask what’s going on and make me take a morning off. I don’t want to push it to the point where the practices are hurting me, so it’s more beneficial to take a morning off rather than getting worse.

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Youth Sports in the U.S.

$15

Billion

Industry in 2017 according to TIME Magazine

Sleep Performance The reason why vaguely trying to “get a good night’s rest” is not effective, and athletes are turning to technological solutions is because of the effects sleep has on athletic performance. As the research studies have shown, a long nights sleep does not always equal a good night of sleep.

On top of athletes putting their bodies through strenuous training, there are a lot of other factors that make it challenging for athletes to get quality sleep. Some of these reasons include late night practice and competitions, traveling long distances for competition, sleeping in a different bed or location due to travel, and looking at screens before bed.

1 Since these factors are inevitable in athletics, having better sleeping habits is not an option. Circumstances like these is why sleep technology 1 is utilized.

Athletes under the age of 18 need more sleep than adults. This contradicts the schedule that school start times create. “Adolescents have greater variability in sleep between weekdays compared to the weekend facilitating accumulative week day sleep debt. This training and education induced sleep deficit, coupled with social jetlag is concerning from an 9 athletic and academic performance development perspective.”

Research also shows that the nature of the sport affects the quality of sleep athletes are able to get. “Differences between the characteristics

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from individual and team sports can influence the sleep quantity, efficiency, and latency of the athlete.” 1 It is not just the lack of sleep that can disrupt the body from repairing, it is the fact that the sleep wake cycle is being disrupted. The most problematic factor that results from sleep inadequate sleep is the lack of recovery. Intense exercise coupled with improper recovery for extended periods of time can cause overtraining syndrome. Overtraining syndrome is when the stress on the body no longer yields athletic improvements and the athletes skills and performance declines. This is because the body is overhauled by stress but has no way to grow or repair the muscles for the continual training. The body is put in such a compromised state that it is 2 more susceptible to injuries and illnesses.

While overtraining syndrome results in a mostly physical weakened state, sleep deprivation primarily attacks the brain’s function. “Sleep deprivation is linked to reduced immune function via reductions in natural killer cells and decreased sub-maximal sustained exercise performance.” 3

Photo from Coachmeplus.com

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One Final Note

Photo from pexels.com

While this book is centered around sleep and recovery, that is not the primary focus of many athletes’ training priorites. The research of the effects of sleep mentally and physically support why sleep and recovery is now becoming the new normal in an athlete’s preperation regimine in today’s society. When coaches or support staff are involved in these recovery centered conversations, it encourages the athlete to manage their sleep health.

The sleep deficit not just athletes, but Americans, are facing is based on new societal factors. It is not a dilema manifested by the wearable technology industry in order to increase their sales. Research shows that sleep is declining every year, and companies are being innovative to fufill this need.

The actigraphy monitors currently on the market, while mainsteam, still cost from 60 to 1200 dollars. No matter if an athlete will purchase one of these devices or not, being intentional about sleep and creating healthy recovery habits should become the standard in all athletes routines.

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About The Author

Melanie Abbott in transition during an NCAA triathlon race in South Dakota on September 21, 2019. Photo by Hadley Jason

My name is Melanie Abbott, and I am a sophomore multimedia production journalism, graphic design and Spanish triple major at Drury University.

I was recruited to attend Drury and compete in the inaugural year of their triathlon team. Triathlon is new at the NCAA level, and it’s unique compared to other sports offered at the college level because it requires more training time than other sports.

The student-athlete balance in this new sport is far from being perfected, and athletes (including myself) get swallowed trying to maintain the typical 30 plus hours a week training and stay afloat in college classes.

The demands of the student athlete lifestyle left me facing many sleepless nights cramming to finish projects into every hour of the night and then hitting the pool at five in the morning.

I was running on empty for a dangerously long time. I was so focused on showing up to every practice and completing every assignment that I was blind to my subpar performance at both of these tasks. My performance was decreasing, and I was becoming injured.

This motivated me to not just tell my experiences as a cautionary tale but to provide athletes with the science of sleep .

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Works 1. Claudino, J., J Gabbett, T., de Sá Souza, H., Simim, M., Fowler, P., de Alcantara Borba, D., Melo, M., Bottino, A., Loturco, I., D’Almeida, V., Carlos Amadio, A., Cerca Serrão, J. and P Nassis, G., 2019. Which parameters to use for sleep quality monitoring in team sport athletes?

A systematic review and meta-analysis. BMJ Open Sport & Exercise Medicine, 5(1), pp.bmjsem-2018-000475.

2. Leeder, J., Glaister, M., Pizzoferro, K., Dawson, J. and Pedlar, C., 2012. Sleep duration and quality in elite athletes measured using wristwatch actigraphy. Journal of Sports Sciences, 30(6), pp.541-545.

3. Miles, K., Clark, B., Fowler, P., Miller, J. and Pumpa, K., 2019. Sleep practices implemented by team sport coaches and sports science support staff: A potential avenue to improve athlete sleep?. Journal of Science and Medicine in Sport, 22(7), pp.748-752.

4. Nedelec, M., Aloulou, A., Duforez, F., Meyer, T. and Dupont, G., 2018. The Variability of Sleep Among Elite Athletes. Sports Medicine Open, 4(1).

5. Sargent, C., Lastella, M., Halson, S. and Roach, G., 2016. The validity of activity monitors for measuring sleep in elite athletes. Journal of Science and Medicine in Sport, 19(10), pp.848-853.

6. Taylor, S., Rogers, G. and Drivers, H., 1997. Effects of training volume on sleep, psychological, and selected physiological profiles of elite female swimmers. Medicine &amp Science in Sports &amp Exercise, 29(5), pp.688-693.

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Cited 7. "WHOOP - The World's Most Powerful Fitness Membership.".

WHOOP, 2020. Online. Internet. 21 Apr. 2020. . Available: https:// whoop.com.

8. Gallup, Inc. "In U.S., 40% Get Less Than Recommended Amount of Sleep". Gallup.com, 2020. Online. Internet. 18 Apr. 2020. . Available: https://news.gallup.com/poll/166553/less-recommended-amount-sleep. aspx.

9. Gregory, Sean. "September 4Th, 2017 | Vol. 190, No. 9 | U.S.".

TIME.Com, 2017, https://time.com/magazine/us/4913681/september4th-2017-vol-190-no-9-u-s/. Accessed 13 May 2020.

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MELANIE ABBOTT 2020