Do athletes need more sleep than the average person? Peta Bee sifts through the findings
Two recent studies have cast doubt on the idea that the average person needs a solid eight hours of sleep every night. It’s a myth, the sleep scientists suggested, and most people can get away with six or seven hours without ill effect. But will the same hold true for athletes or does missing out on nightly recuperation impact your ability to train and perform?
A few years ago, a study involving 27 members of the England Sevens rugby union squad monitored sleep patterns to find out if they might be adversely affecting performance. Over a five-week period, the team’s physiotherapist, Remi Mobed, asked the players to wear actigraphy wristwatches that use movement detectors to measure the duration and quality of sleep. By recording the cycle and rate of movement during the night, actigraphy devices assess phases of sleep and exactly when the wearer is in deep sleep (rather than tossing and turning).
Links to injury
Results were surprising. Players not only inaccurately estimated how long they had slept each night, but most were getting 70 minutes less sleep – roughly a full cycle – than they thought. They reported the duration of sleep based on when they went to bed, but the devices showed that it took longer than they thought to fall asleep, and that they spent less time in deep sleep.
Undoubtedly, said Mobed, this kind of sleep deficit will take its toll. “Sleep is absolutely the most important aspect of recovery from exercise,” he said. “Our findings suggested that players thought they were sleeping well but the results don’t tally. And their poor sleep could be implicated in a wide range of fitness-related problems from injury and illness due to overtraining to lack of strength and power.”
At Stanford University’s sleep disorders clinic, Dr Cheri Mah analysed the sleep-wake patterns of five female athletes over three weeks and asked them to perform a series of athletic tests that included sprinting, tennis serves and other drills. On average, the women were getting six to eight hours’ sleep a night, which, considering their activity levels, was deemed too little. When the same subjects were asked to extend their sleeping hours to 10 per night, their performance in the drills improved significantly and they were able to run faster, hit tennis balls more accurately and exhibit greater arm strength. This suggests that people who are more active may benefit from nine to ten hours’ sleep, more than the average eight hours a night.
A lack of sleep also has physiological implications that can hamper fitness. Men who slept less than five hours a night for just one week were shown to have lower levels of testosterone than when fully rested. In the University of Chicago study of athletic 24-year-old males, it was found that sleep deprivation caused a 10-15% drop in testosterone, a hormone essential for building muscle mass and bone density.
Dr Jonathan Leeder, an exercise physiologist at the English Institute of Sport in Manchester, has researched the effects of sleep loss and says both strength and endurance “can take a knock” as a result. During deeper sleep, human growth hormone (HGH) produced by the pituitary gland is released into the blood. It is HGH that enables essential recovery processes such as repairing muscles and converting fat to fuel. Consequently, too little sleep means the body produces less HGH and more of the stress hormone cortisol that Leeder says “definitely won’t help with muscle recovery and building”.
Sleep on it
If missed sleep is affecting your training, what steps should you take? Mobed recommends investing in an actigraphy watch to monitor your sleep patterns. “Apps that monitor sleep are available but generally not very accurate,” he says. Most people who are active need at least eight hours, or five full cycles. “I advise people to work out a convenient wake time and stick to that as much as possible,” says Nick Littlehales, a sports sleep coach who has worked with Manchester United and British Cycling.