Should You Really Be Worried About Sleep If You’re Trying To Build Muscle?

If you’re on the fitness side of the internet, you’ve likely heard someone discuss the importance of sleep for muscle growth. Whatever influencer you hear it from probably talks about how it’s the longest and most important period of recovery, but is it really that important? 

A study from January 2021 titled, “The effect of acute sleep deprivation on skeletal muscle protein synthesis and the hormonal environment,” answers this question perfectly. The researchers were aware of the fitness industry's debate, and they designed a study that was meant to test how short term sleep deprivation affects rates of muscle protein synthesis and the levels of catabolic hormones, or hormones that promote the breakdown of tissue. The study used thirteen participants, and recorded one night of poor sleep, as well as one night of bad sleep for each participant. On average, each participant’s rate of muscle protein synthesis on the poor night of sleep was eighteen percent lower than the sufficient night of sleep. They also saw a twenty one percent increase in cortisol–a catabolic hormone that you absolutely do not want more of– and a twenty four percent decrease in testosterone, the anabolic hormone that you most definitely want in abundance. 

So yeah, sleep is important when it comes to muscle growth, because if you’re not getting enough, you simply won’t be turning as much protein into lean tissue as you could if you were getting more sleep. 

But I know what you’re thinking. The study was done to assess acute, or short term, sleep deprivation, not its effects over the long term, so what would happen if you were chronically sleep deprived? The study also answered that question, concluding with this statement, “A single night of total sleep deprivation is sufficient to induce anabolic resistance and a pro catabolic environment. These acute changes may represent mechanistic precursors driving the metabolic dysfunction and body composition changes associated with chronic sleep deprivation.” In other words, the detrimental effects of short term sleep deprivation carry over to long term sleep deprivation. 

Hopefully after hearing this you’ll turn the TV off and fall asleep a little sooner, maybe even before this video’s over if it’s already past your bedtime. We recommend seven hours of sleep at the very least, but eight to nine is most likely the target for getting the biggest response to the stimulus you produce by lifting weights.