Sleep Deprivation May Make You Doubt Your Physical Fitness

It may not be solid training or the perfect breakfast that makes you feel prepared for a big sporting event. It could be something as simple as how much you sleep, according to a new study.

Dutch researchers had 11 men perform a 20-minute cycling test in various conditions, including once after a night of sleep deprivation and once without robbing them of their shut-eye. After each test, the cyclists were asked to estimate the distance they believed they had covered over the 20 minutes. In both trials, the men cycled for an average of 7.6 to 7.7 kilometers, around five miles, Runner's World reported. What varied was how far they thought they biked. After a good night's sleep, the men estimated they had ridden 7.26 kilometers. Without any sleep, that guess fell to just 6.51.

"We conclude that subjective estimates of performance are not in line with actual performance for endurance exercise after sleep deprivation," the authors wrote. "In other words," Runner's World reported, "lack of sleep might make you a wimp."

That's good news for anyone whose sleep suffers at the hand of game day jitters: Even if you're feeling less than your best, you won't necessary run a slower race or tank your tennis match.

Still, no need to stay up late on purpose. Regularly getting even just one extra hour of sleep a night has been shown to improve athletic performance, even if more sleep means less time to train.

Sleep Deprivation Can...