If athletes force themselves to sleep two hours longer every day, their reaction speed increases and they get faster. Sleep researchers at Stanford University in the US discovered this when they performed experiments with basketball players.
Too little sleep leads to increased body fat, reduced testosterone levels, and decreased oxygen uptake, and animal studies have shown that it leads to muscle decay as well. On top of this, your immune system works better if you get enough sleep, and there are indications that good-quality sleep can extend your life expectancy.
So it’s logical that athletes perform better if they make sure they don’t miss out on sleep. But can athletes improve their performance by going a step further? By making sure they get lots of extra sleep? In 2011 Cheri Mah of Stanford University published in Sleep the results of a human study that showed this could be the case.
Mah used 11 students from the basketball team for her experiment. She got them to increase the amount of sleep they got to 10 hours a day over a period of 5-7 weeks. Before they started on the ‘sleep extension’ the subjects all slept just under eight hours a day. They thought that this was enough sleep.
Although the textbooks say that eight hours’ sleep is enough, Mah observed that increasing the amount of sleep had a positive effect on the players. She used the Psychomotor Vigilance Task test to measure the players’ reaction times, and discovered that these became faster as a result of more sleep.
In the Psychomotor Vigilance Task the subjects look at a black screen. When a point of light appears they have to press a button as fast as possible.
Before starting to sleep longer the athletes had an average of 16.2 seconds for an 86-m sprint. Extending their sleep reduced this to 15.5 seconds.
The subjects also found that they felt better for more sleep: less angry, depressed, stressed, tired and confused, and they had more energy. In addition their aim became better and more accurate.
“This study reveals an athlete’s inability to accurately assess how much sleep one actually obtains each night, thus leading to a misperception regarding the duration of sleep that constitutes adequate nightly sleep time”, the researchers conclude.
The effects of sleep extension on the athletic performance of collegiate basketball players.
To investigate the effects of sleep extension over multiple weeks on specific measures of athletic performance as well as reaction time, mood, and daytime sleepiness.
Stanford Sleep Disorders Clinic and Research Laboratory and Maples Pavilion, Stanford University, Stanford, CA.
Eleven healthy students on the Stanford University men’s varsity basketball team (mean age 19.4 ± 1.4 years).
Subjects maintained their habitual sleep-wake schedule for a 2-4 week baseline followed by a 5-7 week sleep extension period. Subjects obtained as much nocturnal sleep as possible during sleep extension with a minimum goal of 10 h in bed each night. Measures of athletic performance specific to basketball were recorded after every practice including a timed sprint and shooting accuracy. Reaction time, levels of daytime sleepiness, and mood were monitored via the Psychomotor Vigilance Task (PVT), Epworth Sleepiness Scale (ESS), and Profile of Mood States (POMS), respectively.
Total objective nightly sleep time increased during sleep extension compared to baseline by 110.9 ± 79.7 min (P < 0.001). Subjects demonstrated a faster timed sprint following sleep extension (16.2 ± 0.61 sec at baseline vs. 15.5 ± 0.54 sec at end of sleep extension, P < 0.001). Shooting accuracy improved, with free throw percentage increasing by 9% and 3-point field goal percentage increasing by 9.2% (P < 0.001). Mean PVT reaction time and Epworth Sleepiness Scale scores decreased following sleep extension (P < 0.01). POMS scores improved with increased vigor and decreased fatigue subscales (P < 0.001). Subjects also reported improved overall ratings of physical and mental well-being during practices and games.
Improvements in specific measures of basketball performance after sleep extension indicate that optimal sleep is likely beneficial in reaching peak athletic performance.
PMID: 21731144 [PubMed – indexed for MEDLINE] PMCID: PMC3119836