Sleep and Athletic Performance
We all intuitively know that sleep is important for us as athletes, but just how important is it? There are decades and decades of sleep-related research within the general, non-athletic population documenting the deleterious effects of sleep deprivation on overall psychological and physiological well-being. Sleep deprivation, or insufficient sleep, has been shown to be related to impaired cognitive function, obesity, diabetes, greater cravings for unhealthy foods, impaired glucose sensitivity, impaired protein synthesis, and altered growth hormone and cortisol secretion levels (1). Sleep deprivation also leads to a greater increase in inflammation in the body and ultimately impaired immune function (1). This could all conceivably have a negative effect on athletic performance and recovery.
In athletes specifically, there has been quite a bit less research, but there is still a moderate body of evidence to show that sleep deprivation of as little as a few hours over a few days can lead to reduced performance across a range of different sports, including endurance performance (1). Not only does sleep deprivation lead to poorer physical and cognitive performance, it impairs recovery as well, although there is less research specifically examining sleep deprivation and metrics of recovery. Remember, sleep deprivation can impair muscle protein synthesis and increase the inflammatory state of the body, both of which would affect recovery. On the opposite end of the spectrum, sleep extension studies in which sleep quantity has been bolstered by a few hours has been shown to improve/restore performance across a range of sports and types of performances.
How Much Sleep is Enough?
So, we know that sleep is important when it comes to performance and recovery, but how much do athletes need? Non-athlete adults are recommended to achieve 7-9 hours of sleep each night; however, athletes are known to report getting less sleep than the average non-athlete adult (1). This could be due to the demands to get up early for training, technology acting as a distraction keeping athlete up at night, and demanding travel schedules for some athletes. Nonetheless, whatever the demands are, athletes likely need around 8-9 hours of sleep each night for optimal performance due to the high demands placed upon their body to perform and recover (1).
There is some emerging evidence suggesting that naps taken on days where an athlete might not have slept optimally can be of benefit, but this research is still emerging (1). A practical approach is to aim for 8-9 hours of good quality, uninterrupted sleep each night. On the nights where this is not achieved, a 30-60-minute nap is recommended in the late morning or early afternoon as needed.
How to Achieve Optimal Sleep?
Achieving good quality and quantity sleep is not necessarily difficult, it just takes some discipline. Establishing good “sleep hygiene” habits is the best thing an athlete can do to ensure good sleep patterns. The following strategies are recommended as part of a healthy sleep hygiene routine to promote good sleep (1):
Don’t go to bed until sleepy. If not sleepy, get out of bed and do something else until becoming sleepy.
Regular bedtime routines/rituals help to relax and prepare the body for bed (reading, warm bath, etc.).
Try to get up at the same time every morning (including weekends and holidays).
Try to get a full night’s sleep every night, and avoid naps during the day if possible (if a nap is a must, limit to one hour and avoid nap after 3:00 pm).
Use the bed for sleep and intimacy only, not for any other activities such as TV, computer, or phone use.
Avoid caffeine if possible (if must use caffeine, avoid after lunch).
Avoid alcohol if possible ( if must use alcohol, avoid right before bed).
Do not smoke cigarettes or use nicotine, ever.
Consider avoiding high-intensity exercise right before bed (extremely intense exercise may raise cortisol, which impairs sleep).
What About Travel and Sleep?
Travel is a concern that many athletes have because of its impact on sleep. Jet lag is a very real phenomenon when travelling across different time zones, especially when travelling from west to east. Research shows that travelling across time zones can have a negative effect on athletic performance, particularly within the first 72 hours after landing (1). As a rough guide, jet lag symptoms may last for about one day for each time zone when travelling eastward, and a half-day for each time zone when travelling westward (1). This period of time it takes to adjust from jet lag should be taken into account when travelling for races, in particular, as an athlete would want to allow themselves adequate time to adjust and recover from jet lag before expecting any sort of optimal performance.
Jet lag when travelling northward or southward is not as well understood, but the primary impact on sleep may come from circadian rhythm disruptions due to changes in hours of sunlight (1). Athletes travelling northward or southward should try to spend as much time outside when travelling in these directions and to a new location with different daylight hours. This period of adjustment may also take a few days and should be accounted for when travelling for racing.
Conclusions
Sleep is arguably the most important factor in recovery. Exercise and nutrition are often thought of as the most important factors in determining performance, but sleep should be lumped in there as the third most important factor. The best training and nutrition strategies in the world will be rendered sub-par if an athlete does not sleep well or is chronically sleep deprived. Sleep should be a priority for every single athlete alongside optimizing training and nutrition strategies. Athletes should aim for 8-9 hours of high quality, uninterrupted sleep each night and establish consistent sleep hygiene patterns in order to achieve this goal.
References:
1. Vitale KC, Owens R, Hopkins SR, Malhotra A. Sleep hygiene for optimizing recovery in athletes: review and recommendations. International journal of sports medicine. 2019 Aug;40(8):535.
Happy training and racing!
-Ryan Eckert, MS, CSCS
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