If you’re riddled with guilt every time you hit the snooze button, a new study from Stanford should make you feel better. Varsity basketball players who tried to get 10 hours of sleep per night for five to seven weeks could sprint faster, react faster, and sink more free throws and three-pointers.

In the study, published this month in the journal Sleep, Cheri Mah, a researcher at the Stanford Sleep Disorders Clinic asked 11 players from Stanford’s varsity basketball team to try to boost their nighttime slumber by an hour or two. According to a story in the SF Gate;

The players didn’t quite make it to 10 hours, but they did add more than 90 minutes of sleep time, and the results were noticeable. Collectively, they took almost a full second off of their times in 282-foot sprints on a basketball court - that’s equivalent to the length of a court three times - and they improved the accuracy of both their free-throw and three-point shooting by 9 percent.

“What these findings suggest is that these athletes were operating at a sub-optimal level. They’d accumulated a sleep debt,” said Mah. “It’s not that they couldn’t function - they were doing fine - but that they might not have been at their full potential.”

The athletes wore devices on their wrists that measured time asleep, which showed that most of them overestimated their sleep time. In the first four weeks of the study, when players were asked to maintain their normal sleep schedule, they estimated they slept eight hours but averaged about 6 hours and 45 minutes. While trying to sleep 10 hours during the second part of the study, they actually achieved about 8 1/2 hours.

Given the small size of the study, it’s not yet clear whether the findings will hold true for other athletes, or the general population. But Mah told the SF Gate that the fact that every one of the 11 players saw improvements is strong evidence that extra sleep can elevate athletic performance. The study is one of the number of Mah’s efforts to measure the potential benefits of sleep on athletic performance, as noted in a press release from Stanford;

Over the last several years she has investigated sleep extension in other Stanford sports teams including football, tennis, and swimming. She has presented abstracts with preliminary findings on these sports that suggest a similar trend: More sleep led to better performance.

Earlier this year, Mah helped Zeo, a start-up that makes an at-home sleep monitoring device, create an infographic illustrating the benefits of sleep on athletic performance. It suggests that many pro athletes get more than the average amount of sleep. Roger Federer and Lebron James leed the pack with 11 to 12 hours of sleep. (Tiger Woods is an athletic anomaly, reporting only four to five hours of sleep.)