How many hours would you say you sleep in an average night? If you answered 7-9, the National Sleep Foundation says you’re doing pretty well.
Around 40 percent of us get less than 7 hours though.
If building lean muscle mass is important to you, your lack of shut-eye may be a bigger problem than you think. Let’s dig a bit deeper into what the science says about the effect of sleep on muscle growth.
Not getting enough sleep inhibits your ability to grow muscle
Research shows that being sleep-deprived can actually encourage loss of muscle mass and hinder muscle recovery after a tough workout. Sleep deprivation can have major effects on athletic performance too, especially for endurance athletes.
Lack of sleep affects your ability to grow and repair muscle regardless of your age.
One study showed that a week of sleep deprivation in otherwise healthy young men resulted in decreased testosterone levels and increased spikes of cortisol, a stress hormone. Furthermore, cortisol levels may stay elevated until the following evening when you don’t get enough sleep.
Another study found that from ages 30 to 40, the total amount of growth hormone secreted during a 24-hour span decreases by two-to-three times. So for all you thirty-somethings, you already have biology working against you … don’t compound it by thinking you can get by on 4-6 hours per night (a common range among my more ambitious friends).
Finally, there’s a connection between shorter periods of sleep and weight gain leading to obesity. So even if you’re healthy now, as you age, not getting enough sleep can catch up with you.
There’s a silver lining in all this though …
Getting ample sleep encourages muscle growth
While it’s clear that being under that 7-9 hour threshold may negatively impact your muscle gains, getting some extra rest is a proven way to encourage more muscle growth.
In one sleep extension study, a group of researchers instructed six basketball players to get as much extra sleep as possible following two weeks of “normal sleep”. The researchers found that these athletes exhibited faster sprint times and increased free-throw accuracy at the end of the sleep extension period (as well as decreased fatigue and improved mood).
The same group of researchers conducted another study in which swimmers increased their sleep time to 10 hours per night for 6–7 weeks. These athletes showed improvements in 15 m sprint time, reaction time, turn time, and overall mood.
But you don’t need to sleep for 10 hours a night to see improvements. Getting in that 7-9 hour range is what’s most important.
During those weeks where 7+ hours just isn’t going to happen because of other circumstances going on in your life, there are a couple things you can do, according to science:
- Take a nap. Athletes suffering from some degree of sleep loss may benefit from a brief nap, which can decrease your likelihood of muscle loss.
- Eat some protein (or drink a protein shake) before bed. Eating protein before bed may help your body recover from a workout faster.
Here’s the bottom line about the effect of sleep on muscle growth: if you focus on getting 7-9 hours of sleep every night, you will build more lean muscle and decrease muscle deterioration after age 30.