How much sleep do you need for muscle growth?

Sleep needed for muscle growth: what the sources say

That answers the common searches, with a caveat. For optimal, best, minimum or needed sleep, the one figure from an official source is 7 to 9 hours for adults. No study we found measured muscle size across weeks of lifting while varying sleep, so no source can name a minimum for growth. The 2024 trial compared 5 hours in bed with 7 or more, and that is the closest the evidence comes to a line.^1,3

What short sleep does to muscle in the studies

The 2021 trial put 13 healthy adults through a night of total sleep deprivation and a normal night in random order. After the sleepless night their muscle made about 18% less new protein, and levels of the stress hormone cortisol were 21% higher. The authors describe this as a state that resists muscle building, and note that the markers of protein breakdown did not change.²

The 2018 review looked at performance rather than size. Staying awake all night had little effect on strength, while several nights of shortened sleep could cut force in multi-joint lifts such as squats and presses. Hormone results were mixed. The 2024 trial, in young trained women, found nine nights at 5 hours altered which muscle genes switched on after lifting, and the authors say training on short sleep may not give the same adaptive response.^3,4

These are short-term measurements in small groups, not months of growth. They suggest that sleeping less can alter how muscle responds to training, without telling us how much growth is lost. MedlinePlus adds a general statement that sleep releases growth hormone, which assists in muscle repair.¹

Rest for muscle growth between sets and between workouts

Rest has other meanings in training. Between sets, reviews found 60 to 120 seconds looked enough for beginners and more than 2 minutes appeared to give trained lifters the largest strength gains, which our rest between sets guide covers. Between workouts, MedlinePlus calls rest an important part of training that lets the body recover for the next session, and advises a full day off every week and at least 6 hours between periods of exercise.^6,7

Habits MedlinePlus lists for sleeping better

• Go to bed and wake up at the same time every day.¹
• Avoid caffeine in the afternoon and evening, and avoid alcohol before bed.¹
• Exercise regularly but not too close to bedtime, and avoid large meals and drinks late at night.¹
• Keep the bedroom cool, dark and quiet, and put away screens before bed. MedlinePlus also suggests a gap of at least 2 hours between a heavy meal and sleep.^1,8

Eating before bed: what the protein studies say

In studies of people who lift weights, a bedtime drink of 27.5 to 40 g of casein, a slowly digested milk protein, raised muscle protein building overnight.^9,10

A meta-analysis of randomized trials found that protein taken within an hour before or after exercise did not significantly add strength or muscle size; total daily protein was the strongest predictor of muscle gain.^9,11

Our protein timing page goes through the evidence, and the calculator turns your body weight into a daily range. MedlinePlus advises against heavy meals in the last 2 hours before sleep, so a bedtime drink is a different thing from a late dinner.⁸

Stop and ask a doctor if

• You have continued trouble sleeping. MedlinePlus says to see a provider, because you may have a sleep disorder such as insomnia or sleep apnea.¹
• Pain or discomfort is keeping you awake, you feel sad or depressed, or you have been taking medicines for sleep without talking to your provider first. MedlinePlus lists each as a reason to make contact.⁸
• You take any medicine, diet pill, herb or supplement and are not sure how it affects your sleep. MedlinePlus advises asking your provider.⁸

Questions people ask

Sources

1. MedlinePlus. Healthy Sleep. Last updated December 9, 2025. National Library of Medicine. Opened 2026-10-11.
2. Lamon S, et al. The effect of acute sleep deprivation on skeletal muscle protein synthesis and the hormonal environment (randomized crossover trial of 13 adults). Physiol Rep. 2021;9(1):e14660. Opened 2026-10-11.
3. Knowles OE, et al. The interactive effect of sustained sleep restriction and resistance exercise on skeletal muscle transcriptomics in young females (randomized crossover trial of 10 women). Physiol Genomics. 2024;56(7):506-518. Opened 2026-10-11.
4. Knowles OE, Drinkwater EJ, Urwin CS, Lamon S, Aisbett B. Inadequate sleep and muscle strength: Implications for resistance training (systematic review of 17 studies). J Sci Med Sport. 2018;21(9):959-968. Opened 2026-10-11.
5. Walsh NP, et al. Sleep and the athlete: narrative review and 2021 expert consensus recommendations. Br J Sports Med. 2021;55(7):356-368 (expert consensus). Opened 2026-10-11.
6. Grgic J, Schoenfeld BJ, Skrepnik M, Davies TB, Mikulic P. Effects of Rest Interval Duration in Resistance Training on Measures of Muscular Strength: A Systematic Review. Sports Med. 2018;48(1):137-151. Opened 2026-10-11.
7. MedlinePlus Medical Encyclopedia. Are you getting too much exercise? Review date September 4, 2024. National Library of Medicine. Opened 2026-10-11.
8. MedlinePlus Medical Encyclopedia. Changing your sleep habits. Review date April 10, 2026. National Library of Medicine. Opened 2026-10-11.
9. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals. Updated April 1, 2024. Opened 2026-10-07.
10. Jäger R, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. Opened 2026-10-01.
11. Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013;10(1):53. Opened 2026-10-07.