How Sleep Deprivation Affects Athletic Performance

New research looked the impact of sleep deprivation on the performance of judo players in competition. Less sleep meant less power and worse cardio.

Being sleep deprived for competition is probably the average state for most of us. Last minute travel, jet lag, unfavorable sleeping conditions, and anxiety are amongst the common reasons why we might have a tough time getting a good night’s rest when competing. Often the anxiety or excitement of competition seems to outweigh the fatigue and sleepiness of missing out the night before, but it’s important to understand the real effects of being sleep deprived on performance.

The more we know about how exactly sleep deprivation impacts performance, the better we will be able to adjust and prepare. Even better, if we see the effects of sleep deprivation on the actual sport rather than only lab tests we may get even more of that information that we need. To that end, in a study this month in the Journal of Strength and Conditioning, researchers examined sleep deprivation on the performance of judo players, or judoka.

Like many combat sports and martial arts, judo imposes a broad variety of physical demands on a person, including power, flexibility, endurance, and quick reaction times. Because of the breadth of physical needs to perform well in judo, if sleep deprivation impacted any of them, it would show through in the performance.

The researchers used a few tests including hand grip, an isometric curling test, and a cardio test for testing power output. They also checked on perceived exertion, or how hard the athletes felt like they were working. The tests were done before and after a judo match at two different times of day – 9:00 in the morning and 4:00 in the afternoon. The researchers did the tests at two different times of day to see if the effect on sleep varied depending on the time of competition.

It wasn’t just the competition time that varied. When the sleep deprivation occurred actually varied as well. The judoka each participated in one of three conditions, one in which they received normal sleep (7.5 hours), one in which they got four hours of sleep at the start of the night, and finally, one where they received four hours of sleep at the end of the night. The only difference between the last two groups was when they slept in the night rather than the amount the slept, which is called “partial sleep deprivation,” when you do get some sleep, but not enough.

The results were fascinating. First, without deprivation, the athletes were stronger and had greater cardio power at 4:00PM than 9:00AM. Second, this difference went out the window with sleep deprivation, just as it did after the judo match. That means sleep deprivation had a similar effect as actually exhausting yourself during a performance. Not only that, but the judoka who slept in the beginning of the night and were awoken very early suffered further, with more weakness at the 4:00PM session. The morning session for both sleep deprived groups was the same.

While sleep deprivation clearly affects performance, it seems to get worse the longer your competition is from what little sleep you received. Combating jet lag and other sleep problems before competition with melatonin or similar supplement, and treating anxiety with sport psychology could both go a long way to helping athletes perform better for competition. After all, that’s the name of the game.


1. N Souissi, et. al., “Effects of Time-of-Day and Partial Sleep Deprivation on Short-Term Maximal Performances of Judo Competitors,” Journal of Strength and Conditioning Research, 27(9), 2013.

Photo courtesy of Shutterstock.

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