You're Not Sleeping Enough and It's Costing You Performance

Updated April 2026. Originally published October 29, 2015 By Adam Weaver 

What do elite athletes like Usain Bolt, LeBron James, and Roger Federer have in common? They all sleep 10–12 hours a night. Not just the night before a big race, game, or match—every night.

"So what?" you might say. "They're professionals with nothing else to do." Fair point. But bear with us, because the science behind what those extra hours are actually doing is genuinely worth understanding, and some of it applies directly to you, no matter what level you're training at.

 

Why Sleep Deprivation Hits Athletes Hard

Sleep scientists call it "sleep debt," and most athletes are carrying more of it than they realize. Whether it’s from jet lag, early training sessions, or pre-competition anxiety, the effects of not getting enough rest go deeper than just feeling groggy.

When you're sleep deprived, your muscles will contain less glycogen (the stored carbohydrate energy that fuels endurance and high-intensity efforts). That means even if your nutrition is dialed in, poor sleep can leave your muscles under-fuelled before you even start. Your reaction time slows, decision-making suffers, and motor coordination weakens. 

It’s the kind of subtle degradation that's easy to miss in training but shows up when it matters. Frustration and irritability can creep in too, and in our experience, that's often when athletes start picking up injuries they otherwise wouldn't.

The injury link isn't just anecdotal. Athletes sleeping fewer than 8 hours per night are 1.7 times more likely to sustain a musculoskeletal injury than those who sleep more. Even a reduction of just 1–2 hours per night can measurably impair speed, explosive power, and accuracy in skill-based sports, and those deficits compound over days and weeks of chronic shortfall.

What Happens When You Sleep More

So, what if you go the other way and actively try to sleep more? What happens when we do a “LeBron”? The research here is compelling.

A pioneer in this area is Stanford's Cheri Mah, who has spent years working with elite and collegiate athletes, tinkering with their sleeping patterns. In her landmark study with the Stanford basketball team, she found athletes who extended their sleep to 10 hours per night improved sprint times, free throw accuracy (up 9%), 3-point accuracy (up 9.2%), reaction time, and mood. She found similar results with swimmers, who clocked 0.5 seconds faster over 15 metres with 0.15-second faster reaction times after sleep extension. She went on to replicate the findings in tennis, football, and more.

What’s happening here? Is sleeping in something you should add to your supplement stack?

The Deep Sleep and Recovery Connection

Hard training changes how you sleep. After a tough session, you usually fall asleep faster and spend more time in deep sleep. This is your biology doing exactly what it should and shifting into recovery mode. The real question is whether you’re giving it enough time in bed to finish the job. 

When we enter deep sleep, our bodies dump growth hormone into our bloodstream (about 50% of our daily dose in just a few hours). Growth hormone is the fountain of youth—it repairs muscles, builds bones and even burns fat. Just what the body ordered to recover from the day’s training load and get ready for more.

Cut your sleep short, and that growth hormone pulse is blunted. Your body moves away from repair and toward breakdown. Which might help explain why LeBron, Usain, and Roger take sleep so seriously. They're not just resting, they're optimizing.