Research · 3 min read · 2026-10-12
Sleep and running
Athletes who slept almost two hours more per night got faster and felt less tired. What sleep loss costs and what to do about it.
Most runners know that sleep matters, but few plan for it the way they plan their training. What happens when athletes sleep more, and what does too little sleep cost?
What the researchers did
In a study at Stanford University, 11 basketball players kept their normal sleep for two to four weeks. For the next five to seven weeks, they tried to spend at least ten hours in bed each night. The researchers measured their sleep, timed a sprint and recorded their shooting after every practice.
A review from 2015 went through the research on sleep loss and exercise performance.
What they found
The players slept almost two hours more per night. Their sprint time improved from 16.2 to 15.5 seconds, and their free-throw and three-point shooting both improved by about 9 percent. They reported less fatigue and felt better during practice.
The review found more mixed results for sleep loss. Some maximal efforts held up after a poor night, but the few studies of athletes found that sport-specific performance got worse. Thinking was slower and less accurate. Poor sleep over time could also give symptoms that resemble overtraining.
What it means for you
Sleep is part of your training. If you are building up to a race or have a hard block of training, more sleep is one of the simplest things you can add.
One bad night before a race is common and rarely ruins the result. Several weeks of too little sleep are a different matter. Then it is better to make the training a bit easier than to push through.
What the studies can't tell you
The sleep extension study had 11 young male basketball players and no control group. Sprint and shooting are not the same as endurance running. The review describes the results as uncertain and calls for more research.
How we use it
PX7 Training asks how you feel before a session. If you have slept badly for several nights, say so, and the next session adjusts.
Sources
- Mah et al. (2011), The effects of sleep extension on the athletic performance of collegiate basketball players. Sleep.
- Fullagar et al. (2015), Sleep and athletic performance: the effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise. Sports Medicine.
Written by Jørgen Larsen for PX7 Training.