- Most athletes need at least eight hours of sleep, and many perform better with nine or more. Most get less than that.
- Cheri Mah and colleagues (Sleep, 2011) found Stanford basketball players who extended their sleep ran faster sprints and shot about 9 percent more accurately.
- Matthew Milewski and colleagues (Journal of Pediatric Orthopaedics, 2014) found adolescent athletes sleeping less than eight hours were about 1.7 times more likely to be injured.
- Athletes often sleep worse than non-athletes, because of early training, late competition, travel and pre-competition nerves.
- Sleep is the recovery tool most athletes cut first, while spending money on recovery tools with a fraction of its evidence.
In This Article
Most athletes need at least eight hours of sleep a night, and many perform measurably better with nine or ten. Most of them get less. The gap shows up in sprint times, shooting accuracy, reaction speed, mood and injury rates, and it is one of the cheapest performance problems in sport to fix.
It is also the one most athletes are least willing to fix, because sleep does not feel like training.
How much sleep do athletes need?
The general guidance is a starting point. The National Sleep Foundation's recommendations, published by Max Hirshkowitz and colleagues in Sleep Health in 2015, are seven to nine hours for adults and eight to ten for teenagers.
Athletes in heavy training sit at the top of those ranges, because training creates a recovery demand that ordinary life does not. Deep sleep is when growth hormone release peaks, when damaged tissue does much of its repair, and when the nervous system does most of its restoration. Sleep is also when the brain consolidates the motor learning from practice, the thousands of small adjustments that turn drills into skill.
The most useful answer is not a single number. It is: enough that you wake without an alarm most days, stay alert through the afternoon, and are not relying on caffeine to train. For most athletes that means eight to ten hours in bed.
What more sleep did for Stanford's basketball team
The study that changed how many coaches think about sleep came from Stanford.
Cheri Mah and colleagues, including the sleep medicine pioneer William Dement, worked with eleven players from the Stanford men's basketball team. After a baseline period on their normal schedules, the players were asked to aim for ten hours in bed each night for five to seven weeks. The results, published in Sleep in 2011, were striking. Sprint times improved. Free-throw accuracy rose by about 9 percent, and three-point accuracy by a similar margin. The players reported better mood and less daytime sleepiness.
The sample was small and the players knew what was being studied, so the exact figures should be held loosely. But the direction was unambiguous, and it has been echoed in other sports since. These were already elite athletes. The only thing that changed was sleep.
Does sleep loss increase injury risk?
The injury evidence is the part that should concern student-athletes and their coaches most.
Matthew Milewski and colleagues surveyed middle and high school athletes and matched their answers to injury records, publishing the results in the Journal of Pediatric Orthopaedics in 2014. Athletes who slept less than eight hours a night were about 1.7 times more likely to have had an injury than those who slept eight hours or more. Alongside school grade, hours of sleep was one of the strongest predictors of injury in their analysis.
The mechanism is not mysterious. Sleep loss slows reaction time, degrades coordination and balance, impairs judgment about risk, and reduces the body's capacity to repair the small amounts of tissue damage that training always causes. Each of those raises the odds of the landing that goes wrong.
Short sleep also leaves athletes more exposed to illness. Aric Prather and colleagues found in Sleep in 2015 that adults sleeping less than six hours were about four times more likely to develop a cold after being exposed to the virus. For an athlete, a missed week to illness is a missed week of training.
Why do athletes sleep so badly?
You might expect people who train hard to sleep well. Often they do not.
Jonathan Leeder and colleagues measured sleep in elite British athletes using wristwatch actigraphy, publishing the results in the Journal of Sports Sciences in 2012. Compared with non-athlete controls, the athletes spent a similar amount of time in bed but slept less efficiently, taking longer to fall asleep and spending more of the night awake.
The reasons are built into the sport:
- Early training. Morning sessions cut the end of the night short, especially for teenagers, whose body clocks naturally run late.
- Late competition. Evening games leave athletes wired with adrenaline and caffeine at the hour they should be winding down.
- Travel. Time zones, buses and unfamiliar beds.
- Nerves. Nicole Juliff, Shona Halson and Jeremiah Peiffer found in the Journal of Science and Medicine in Sport in 2015 that 64 percent of Australian athletes reported sleeping worse than usual before an important competition at least once, mostly because of thoughts about the event.
Student-athletes carry all of that plus a full academic workload, which usually means the late-night study session lands on the same night as the early training alarm. The all-nighter before an exam and the 6 a.m. practice are drawing on the same account.
The recovery paradox
Here is the part that makes this an optimization problem rather than a knowledge one.
Walk into most training environments and you will find athletes investing in recovery: compression boots, ice baths, massage guns, supplements, wearables that score their readiness each morning. Some of those tools have modest evidence. None comes close to the evidence for sleep.
And yet sleep is the recovery tool athletes cut first. It is the flexible variable, the thing that gives when training, study, travel and social life all want the evening. The result is an athlete spending money on recovery at the margins while running a deficit in the one recovery input that matters most.
Shona Halson's work at the Australian Institute of Sport, which we discussed in What World Cup Players Know About Recovery, has consistently put sleep at the top of the recovery hierarchy. The gadgets are not useless. They are just being asked to make up for something they cannot.
There is also a trap in the tracking itself. Wearables that score sleep can make some athletes anxious enough about their numbers to sleep worse, a pattern researchers have called orthosomnia. The aim is more sleep, not a better score.
What this means for student-athletes and coaches
The group with the most to gain is also the group with the least control over its schedule.
Teenagers' body clocks shift later during adolescence, which is why the American Academy of Pediatrics recommended in 2014 that middle and high schools start no earlier than 8:30 a.m. A 6 a.m. practice asks a teenage athlete to be awake and coordinated at a point in their circadian cycle that is closer to the middle of their night. Add evening homework and a late game, and eight hours becomes arithmetically impossible several nights a week.
That is a scheduling problem, not a discipline problem, and it has scheduling solutions. Coaches who move the hardest sessions later in the day, protect a no-practice morning after late games, and treat reported sleep as seriously as reported soreness are not being soft. On Milewski's numbers, they are running an injury prevention programme that costs nothing.
How athletes can get more sleep
The advice is simple. Following it is the hard part.
- Set a fixed wake time and count back. If practice means waking at 6, lights out needs to be around 9:30 to 10 to get eight hours in bed.
- Bank sleep before big events. Because one bad night before competition is common, the nights leading into it matter more. Several well-slept nights make a single poor one far less costly.
- Nap strategically. A 20 to 30 minute nap in the early afternoon helps athletes who cannot extend their nights, as long as it does not push bedtime later.
- Cut caffeine by early afternoon. Its effects last far longer than they feel.
- Build a wind-down after late games. Dim light, no screens for the last half hour, and something calm. Adrenaline takes time to clear.
- Treat sleep as part of the programme. Write it into the training plan. Sleep that is scheduled is sleep that happens.
The reframe
Most athletes would never skip a training session because they were busy. Most skip sleep for exactly that reason, several nights a week, without thinking of it as missing anything.
Sleep is not the reward for finishing the work. For an athlete, it is where the work turns into adaptation. If you keep cutting it, you are training hard and recovering at a discount, and your body is keeping count even if you are not.
We wrote about the psychology that makes rest feel so hard for athletes in Why You Keep Overtraining.
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Frequently Asked Questions
How much sleep do athletes need?
Most athletes need at least eight hours, and many perform measurably better with more. The National Sleep Foundation's recommendations are seven to nine hours for adults and eight to ten for teenagers, and athletes in heavy training sit at the upper end because of the added physical load. In Cheri Mah's 2011 Stanford study, basketball players who aimed for ten hours in bed for several weeks improved sprint times and shooting accuracy. The practical answer for most athletes is to aim for eight to ten hours and judge by performance and daytime alertness rather than by a fixed number.
Why do athletes sleep so much?
Because training creates a large recovery demand, and sleep is when most of that recovery happens. Deep sleep is when growth hormone release peaks and when the nervous system does much of its restoration, and sleep also consolidates the motor learning from practice. Athletes who sleep a lot are usually not lazy. They are paying back the physical cost of their training, and Cheri Mah's Stanford study suggests many of them would benefit from even more.
Does sleep affect athletic performance?
Yes, strongly. Cheri Mah and colleagues found in Sleep in 2011 that when Stanford basketball players extended their sleep, their sprint times improved and their free-throw and three-point accuracy each rose by about 9 percent. Sleep loss also impairs reaction time, decision-making, mood and motivation. Some effects of a single bad night are small, but repeated short sleep accumulates, and athletes rarely notice how much it is costing them.
Does lack of sleep increase injury risk in athletes?
The evidence points that way. Matthew Milewski and colleagues published a study in the Journal of Pediatric Orthopaedics in 2014 finding that adolescent athletes who slept less than eight hours a night were about 1.7 times more likely to have an injury than those who slept eight hours or more. Sleep loss slows reaction time, impairs coordination and reduces the body's ability to repair tissue, all of which plausibly raise injury risk.
Why can't athletes sleep the night before a competition?
Pre-competition nerves raise arousal at exactly the time the body needs to wind down. Nicole Juliff, Shona Halson and Jeremiah Peiffer found in the Journal of Science and Medicine in Sport in 2015 that 64 percent of Australian athletes reported sleeping worse than usual at least once before an important competition, mostly because of thoughts about the event and nervousness. The useful response is to protect sleep in the nights before, because one poor night before competition matters less when the week leading into it was well-slept.