While this equation may not be a surprise to conscientious fitness professionals, it can be helpful in encouraging athletes—professional or otherwise—to get more shuteye. A study in the July issue of SLEEP (doi: 10.5665/sleep.1132) draws a strong correlation between sleep extension and athletic performance.

Researchers from Stanford University wanted to see whether extending sleep time in the weeks prior to competition would improve game-day performance. They recruited 11 men’s varsity basketball players and asked them to sleep fewer than 7 hours per night for 2–4 weeks during playing season. The players were then asked to be in bed for at least 10 hours per night for 5–7 weeks. Various basketball-oriented measures of performance, such as sprinting and free-throw accuracy, were tested during each sleep protocol. When the researchers analyzed the data, they discovered improved performance on all measures during the sleep extension period. The athletes also expressed higher ratings of physical and mental well-being during practices and games in that period.

The study authors suggested that “improvements in specific measures of basketball performance after sleep extension indicate that optimal sleep is likely beneficial in reaching peak athletic performance.”