Can I still build muscle on five hours of sleep a night?

Yes, most likely! The study is, of course, not the be-all-end-all answer to the question (no study ever is), but it gives strong evidence pointing toward five hours a night being probably fine. You can read the full text of the 2024 study here. The participants were men who did not usually do any strength training, and they were excluded from the study if they had any diagnosed sleep disorders. The 36 men were divided into three groups: a group that averaged seven hours of sleep per night, a group that averaged five-ish hours a night, and a control group that averaged more than seven hours a night.

The control group did not exercise in the study. The seven-hour and five-hour groups did. (Perhaps we can think of the control group as the “what if I slept in instead of hitting the gym? ” group. ) The results?

For some muscle groups, the seven-hour group got slightly better gains than the five-hour group, but for others. they were roughly even. Both groups gained more muscle than the non-exercising control group. The authors write: “The results of the present study suggest that the value of 7 hours as a minimum night sleeping time can be relaxed when it comes to a recuperative state related to muscle strength performance. ” The study has its limitations, including the fact that it was all men, that they used resistance bands instead of barbells or dumbbells, and that the subjects were untrained to start with (making it easier for them to grow muscle).

But the results match up with what pretty much any trainer or fitness enthusiast could tell you: A full night’s sleep is great to have, but not essential to making progress in the gym.