How does sleep deprivation affect athletes?
Even a night or two of poor sleep, or a small but steady sleep debt building up over time, say, one less hour a night affects reaction time, attention, focus and physical recovery. The body does its repair work during sleep, which makes it essential for recovering from intense training. A well-rested athlete isn’t burning any energy just trying to stay awake or focused, which frees up both body and mind to concentrate purely on performance.
Poor sleep reduces reaction time. Mild sleep deprivation doesn’t seem to affect aerobic capacity much, but it does hit reaction time hard. Even small amounts of fatigue can meaningfully slow reaction times and degrade performance. A 2000 study found that pulling an all-nighter affects reaction time in a similar way to a blood alcohol level of 0.05%, cutting reaction times by roughly half in either case.
That slower reaction time isn’t just about performance either, it raises injury risk too. A 2014 study in the Clinical Journal of Sports Medicine found that adolescents playing a game after fewer than 8 hours’ sleep the night before were nearly twice as likely to get injured.
Lack of sleep lengthens recovery. Poor sleep extends an athlete’s immediate recovery time, and the long-term effects can be serious — left unaddressed, sleep issues have the power to shorten a career. A 2013 study published by the American Academy of Sleep Medicine followed 80 Major League Baseball players across three seasons. Their sleep habits were recorded before the 2010 season and ranked using the Epworth sleepiness scale. Players who scored high for sleepiness were less than 40% likely to still be playing three seasons later, compared with 72% of players who scored low.
Sleep, stress and mental focus
Sleep deprivation’s effects aren’t purely physical, it hits mental focus, mood and stress levels too.
Anyone involved in endurance sport knows the value of a positive mindset. High-performance athletes and Olympians regularly credit part of their success to strong visualisation practice and a positive outlook. Sleep deprivation has a real impact on mood, and the irritability it causes can get in the way of an athlete’s ability to stay positive and keep their head in the game.
Research also links sleep deprivation to raised cortisol, the stress hormone. Athletic performance already carries plenty of stress without adding more. Competitive athletes often struggle to fall asleep before a big event, simply from nerves.
In Major League Baseball, “strike-zone judgement” — a player’s tendency to swing at pitches outside the strike zone, might be expected to improve over a season as players rack up more practice and game time. One study of 30 teams found the opposite: judgement actually worsened toward the end of the season, driven by mental fatigue from a long season full of travel.
Less sleep, lower energy for endurance athletes
Sleep deprivation has also been shown to inhibit the production of glycogen and carbohydrates, a critical energy source during sustained activity like high-intensity weight training or endurance events such as marathons. Deplete those stores, and athletes end up with less natural energy to draw on, sometimes leaning more heavily on supplements that can carry their own unwanted side effects.
Do athletes need more sleep?
Research consistently shows performance improves with sufficient sleep and rested athletes are faster, more accurate, and quicker to react.
Stanford University’s Sleep Disorders Clinic and Research Laboratory has studied athletes across basketball, track and field, tennis, golf and cross country. The evidence, usually drawn from fairly small sample sizes, points the same way: more sleep tends to mean better physical performance.
Swimming. In 2007, researchers had a group of swimmers sleep 10 hours a night for six to seven weeks and found notable gains — faster swim times, quicker reaction and turn times in the water, and an increased kick stroke count.
Football (American). A similar 10-hours-a-night regime during heavy training produced comparable results for football players — 20-yard and 40-yard sprint times both improved by 0.1 seconds, alongside better reported mood.
Tennis. Women’s tennis players who increased their nightly sleep to 10 hours saw sprint times improve by 1.5 seconds and serve accuracy improve by 23.8%.
Basketball. A 2011 study found that basketball players who got two extra hours of sleep a night saw speed improve by 5% and shooting accuracy, for both free throws and three-pointers, improve by 9%.
Across every one of these studies, pushing athletes in heavy training to sleep longer than the average person led to genuinely significant performance gains.
How much sleep should athletes get?
Trainers widely recognise the benefit of longer sleep for athletes in heavy training. The general recommendation for an adult is 7–9 hours a night. Adult athletes should aim closer to 10 hours in the weeks around training blocks and competitions, to support both performance and efficient recovery. Adolescent athletes should aim for at least 9 hours.
If a full night isn’t possible, naps can help make up some of the shortfall, though they’re far from ideal as a regular solution. Keep naps to 30 minutes or less, and avoid them right before practice or competition, since waking from a longer nap can leave you groggier than before.
Why sleep matters so much for athletes
Sleep matters for everyone, but especially for athletes. It’s when the body recovers from the physical stress of the day, and when the brain processes and commits new information to memory.
Does sleep deprivation affect male and female athletes differently?
Women are statistically more prone to sports-related injury than men. Most commonly ankle sprains, rotator cuff injuries, tendonitis, ACL tears, stress fractures in the foot or shinbone, and plantar fasciitis. That’s not down to fitness levels. Harvard Medical School researchers point instead to basic physiological differences between the sexes. Higher oestrogen levels, looser ligaments, narrower knees and a wider pelvis all affect how women move. Female athletes can work against this with targeted strength work (particularly the hamstrings, given their link to ACL injury), practising landing from jumps with knees further apart, and using shoe inserts to help prevent foot injuries.
Women are also more prone to sleep disorders like insomnia, which can get in the way of good-quality sleep though on the plus side, research shows women tend to recover from sleep debt faster than men do.
What about sleep in the teenage years?
This can be a genuine challenge once your child becomes a teenage athlete, as their sleep patterns can shift dramatically. They still need quality sleep, but it may happen at different times of day than you’d expect. Hormonal changes make teenagers naturally more inclined to stay up later and sleep in, rather than manage an early night.
Plenty of teenagers are sleep-deprived, which can genuinely hurt performance. Where you can, letting them lie in, or accepting that their sleep may fall at different points across the day, is absolutely fine. It can look like laziness from the outside, but it’s largely outside their control.
How does sleep affect growth hormone production in athletes?
Researchers believe long, heavy sleep supports performance partly because growth hormone is released during deep sleep, and extra sleep encourages more of it. HGH released during deep sleep supports tissue repair and recovery in the body and muscles — important for sustaining performance across an athlete’s career. Both exercise and sleep naturally support HGH production. Some elite athletes look for a competitive edge by taking HGH supplements, though this carries its own separate risks and considerations.
Sleep tips for athletes
Practise good sleep hygiene. Keep a regular sleep schedule, even at weekends. Reserve the bedroom for sleep, not other activities. Build a consistent bedtime routine, doing the same things each night to help train the body to wind down.
The ideal bedroom temperature for sleep sits around 18°C. Athletes may benefit from it being a touch cooler still, given how much more they sweat and how warm they tend to run after a day of activity.
Avoid caffeine and alcohol, particularly in the days before an event, and steer clear of sleep aids or medication unless prescribed by a doctor, since they can interfere with performance.
Avoid exercising late at night. Sleep is triggered and sustained by a drop in body temperature, so avoid raising it right before bed. Save training and high-intensity sessions for the morning or afternoon instead, ideally outdoors and paired with natural daylight, which helps keep the body’s circadian rhythm on track.
Reduce the effects of jet lag. Travel and jet lag are a real factor for athletes trying to sleep well. Jet lag tends to hit harder travelling east than west, so athletes travelling less, or heading west, may have a genuine edge over opponents simply from being better acclimatised to the time zone — sleep researcher Dr Christopher Winter has described this as a “circadian advantage,” giving new meaning to home advantage. Where possible, aim to arrive a few days early to help the body adjust to a new time zone before competing.
Thank you to Tuck Sleep for contributing this article to our site. They are a non-commercial community devoted to improving sleep hygiene, health and wellness through comprehensive, unbiased, free web-based resources.
