This is part 4 of a series about the importance of sleep to athletes. Part 1 was “Improve Athletic Performance By Taking A Nap.” Part 2 was “Reduced Quality Of Sleep In Athletes.” Part 3 was “The Effect Of Sleep Deprivation On Athletic Performance.” Please subscribe to this blog for future installments and other interesting content.
My wife, Jessica, is an Ultramarathoner (you run an ultra, you get a capital “U”). I have always been amazed at her powers of recovery. She ran a couple marathons last year as training exercises for a 50 mile race. She can run for hours on one day, then wake up the next day and do it again. What is her secret? Aside from being naturally gifted and very determined, she gets a lot of sleep; much more than me. Is she on to something? There is some research, in fact, that does demonstrate that extended sleep enhances athletic performance.
All of the most current research on this subject is from one institution, Stanford. There are some limitations to the study designs and to the accessibility of the data, which will be discussed later. One study has been published as a full peer-reviewed manuscript and will be the focus of most of this article. In this study, 11 members of Stanford’s varsity men’s basketball team maintained their usual sleep-wake schedules for 2-4 weeks, then extended their sleep for 5-7 weeks. During the period of sleep extension, the participants were to obtain as much nocturnal sleep as possible with a minimum goal of 10 hours in bed each night. Per journal entries, the participants’ sleep increased from a baseline average of 470.0 minutes per night to 624.2 minutes per night during the study period. Per actigraphy measures, baseline and study measures were 400.7 minutes and 507.6 minutes, respectively. To translate this information into hours, during the study period the participants were in bed for 10.4 hours and actually slept 8.46 hours. Incidentally, at baseline the participants were sleeping less than 7 hours a night, which is not atypical, but less than national recommendations for sleep (7-9 hours per night). Variables measured included timed sprints (the participants ran a back-and-forth shuttle across the basketball court), shooting accuracy, reaction time, levels of daytime sleepiness, and mood. At the end of the period of sleep extension, compared with baseline, participants demonstrated a faster sprint time (15.5 seconds vs 16.2 seconds), an increase in free throw shooting accuracy of 9%, an increase in 3-point field goal shooting accuracy by 9.2%, faster reaction time, decreased sleepiness sales, and improved mood, including, during practices and games, improved overall ratings of physical and mental well-being. Incidentally, this improved speed, shooting, and mood did not lead to a better record for the men’s basketball team. Their record in the 2005-2006 season was 16-14, while it was 18-13 in the previous and subsequent seasons. There are hundreds of variables that go into the performance of a basketball team over a season, so these results are merely interesting, not instructive.
These Stanford researchers also did very similar studies in varsity swimmers, football players, and tennis players. The results have only been reported so far in abstract form, and, so, are not available for a great deal of scrutiny. These studies appeared to show similar results to the basketball players. For example, swimmers decreased their 15 meter sprint swim times from 6.98 to 6.47 seconds, decreased their reaction times from 0.88 to 0.73 seconds, decreased their turn times from 1.10 seconds to 1.00 seconds, and increased their kick strokes from 26.2 to 31.2, after the period of sleep extension. The football players decreased their 40 yard dash times from 4.71 seconds to 4.61 seconds, after the period of sleep extension.
There are important limitations to these research findings, however. The most obvious limitation is the lack of a control group in these studies. It is reasonable to expect that well-coached collegiate athletes will improve their performances over 5-7 weeks and it is unknown if these athletes would have improved, to some degree, regardless of their sleep schedules. My impression, however, is that shooting accuracy and reaction times are unlikely to change so significantly just from coaching and training over 5-7 weeks. Indeed, the concern for many athletes is fatigue over the course of an athletic season. These athletes did not appear to experience this fatigue. Another limitation is the fact that the researchers have not published three of their abstracts, dated 2008, 2009, and 2010, as full manuscripts. This suggests that their data may have other weaknesses that have led to rejections by medical journals over the past seven years. For busy athletes, however, the most important weakness is the difficulty of applying these results to real life. Not many people have the flexibility and freedom to be in bed for 10.4 hours every night for an athletic season.
In spite of the limitations of the research presented, it does appear that extended periods of increased sleep do lead to important enhancements in athletic performance. This effect appears to be applicable to both skills and endurance and to both team and individual sports.
Just like eating right, practicing skills, and training endurance, maximizing sleep can let an athlete reach his or her full potential.
Published March 24, 2015
Mah CD, Mah KE, Dement WC. Extended sleep and the effects on mood and athletic performance in collegiate swimmers. Journal of Sleep and Sleep Disorders Research. 2008;31(Suppl.):0384.
Mah CD, Mah KE, Dement WC. Athletic performance improvements and sleep extension in collegiate tennis players. Journal of Sleep and Sleep Disorders Research. 2009;32(Suppl.):0469.
Mah CD, Mah KE, Dement WC. Sleep extension and athletic performance in collegiate football. Journal of Sleep and Sleep Disorders Research. 2010;33(Suppl.):0304.
Mah CD, Mah KE, Kezirian EJ, et al. The effects of sleep extension on the athletic performance of collegiate basketball players. Sleep. 2011;34:943-950.