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5 Reasons Why You Need Sleep for Muscle Growth


calendar-iconDecember 27, 2018

Foundational Sleep Series


In this day and age, the importance of sleep is often overlooked. As a result, millions of people are consistently sleep deprived. This can cause adverse effects on one's health. Sleep deprivation has become so common that the United States National Institute of Health has described it as a global epidemic.

Neglecting quality sleep is harmful to various areas of your life and it can also hamper your ability to achieve muscle growth and fat loss. This article aims to illustrate 5 ways that sleep can positively contribute to your fitness goals and the repercussions of not getting enough sleep.

1. Sleep prevents muscle breakdown

We hypothesized that sleep debt decreases the activity of protein synthesis pathways and increases the activity of degradation pathways, favoring the loss of muscle mass and thus hindering muscle recovery after damage induced by exercise, injuries and certain conditions associated with muscle atrophy, such as sarcopenia and cachexia.

Medical Hypotheses Journal

Folks that do not get enough sleep end up losing muscle. Sleep deprivation has been shown to increase the activity of biological pathways such as cortisol ("the stress hormone") that lead to muscle breakdown.1  

In other words, by sleeping more, your muscles maintain their strength.

2. Your muscles grow during sleep

Among the hormonal changes, there is an increase in cortisol (humans) and corticosterone (rats) secretion, and a reduction in testosterone and Insulin-like Growth Factor 1, favoring the establishment of a highly proteolytic environment.

Medial Hypotheses Journal

Certain stages of sleep promote the release of hormones, such as growth hormone; these are responsible for building muscle.1  If you don't get a good night's sleep, your body does not hit every sleep cycle, and when that happens, then your muscles miss the opportunity for optimal growth.

3. Sleep helps your body perform better for longer periods

Examination of the various hormonal and metabolic parameters which have been measured in the studies reviewed reveals that the major metabolic perturbations accompanying sleep deprivation in humans are an increase in insulin resistance and a decrease in glucose tolerance. This may explain the reduction in observed time to exhaustion in sleep-deprived subjects.

VanHelder & Radomski

Sleep is critical for having enough energy to crush your workout. On the flip side, not getting enough sleep means that your body is not as efficient at converting food into energy, therefore you will get tired sooner. Sleep deprivation in athletes reduces glucose metabolism (the conversion of sugars into fuel for muscles) by as much as 40%, causing exhaustion 20% sooner! 2-3

4. More sleep helps workouts feel easier

Ratings of perceived exertion always increased during exercise in sleep-deprived (30 to 60 hours) subjects compared with normal sleep,

VanHelder & Radomski

Every workout involves not only overcoming physical limits but mental limits as well. Believe it or not, sleep plays a big factor in your perception of how tired you are, or your rate of perceived exertion. In other words, not getting enough sleep will make you think your body is more tired than it actually is, and your workouts will pay the price!2-3

5. Your muscles are stronger after a good night's rest

Trend analysis indicated decreased performance in submaximal lifts for all the 4 tasks: the deterioration was significant after the second night of sleep loss

Reilly & Piercy

Sleeping a full night not only helps your muscles get stronger and grow bigger, but it also helps them be stronger during the day.4-5 If you were to go lift weights 3 different days, one day after sleeping poorly, another day after getting a mediocre night of sleep, and lastly on a day after a very restful night, you will find that you can lift the most weight the day that you slept the most.

Why is that? Because getting enough sleep allows your muscles to activate beyond their normal abilities. On the flip side, sleep deprivation actually prevents your muscles from operating at their full potential.4-5

The Takeaway

Sleeping is critical when it comes to supporting muscle growth. A good night's sleep can push you further towards your goals. But don't fret, if you don't sleep well one night, it doesn't automatically erase the gains from your training program, but it is important to prioritize getting a regular sleep schedule with enough hours of sleep.

The next post in this series will cover how sleep can also affect your fat loss goals.


  1. Dattilo M, Antunes HK, Medeiros A, et al. Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis. Med Hypotheses. 2011;77(2):220-2. Link
  2. Vanhelder T, Radomski MW. Sleep deprivation and the effect on exercise performance. Sports Med. 1989;7(4):235-47. Link
  3. Myles WS. Sleep deprivation, physical fatigue, and the perception of exercise intensity. Med Sci Sports Exerc. 1985;17(5):580-4. Link
  4. Chen Y, Cui Y, Chen S, Wu Z. Relationship between sleep and muscle strength among Chinese university students: a cross-sectional study. J Musculoskelet Neuronal Interact. 2017;17(4):327-333. Link
  5. Reilly T, Piercy M. The effect of partial sleep deprivation on weight-lifting performance. Ergonomics. 1994;37(1):107-15 Link
Date Created: December 27, 2018

Last Updated: April 2, 2020

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