The Optimized Gentleman

Does Lack of Sleep Affect Muscle Growth In Men?


Muscle growth is a very nuanced topic – it’s not just about what you do at the gym, and what goes into your body. In other words, many lifestyle changes contribute to muscle gain or loss. But today’s question is whether proper sleep is one of those factors or not. If you’re working towards perfectly toned abs, plenty of lean muscle mass and a six pack, you’re going to want to know! So, follow along as we answer all your questions about it here…

The Short Answer to Sleep & Muscle Growth:

In short, YES, lack of sleep negatively affects muscle growth. It can undermine your diet and exercise efforts to build muscle mass. As for exercise, sleep time is a chance for your body to restore itself. It leaves you energized, to have a killer workout the following day. But it’s more than that!


Aside from refueling your energy, it’s also when several muscle-building hormones get to work…

To elaborate, glucose is the only sugar type your body breaks down, to provide you with energy. It stores blood glucose in your muscles as muscle glycogen. As you might’ve already guessed, this process happens during sleep.

So, poor sleep translates to your body not maximally replenishing muscle glycogen.

As for dieting, the human growth hormone (HGH) floods your bloodstream during sleep too. This hormone is essential for muscle growth and recovery – it allows your body to use the amino acids in the proteins you consume.

Having optimal levels of testosterone and HGH is essential for male development, strength, virility, mood, sleep, and so much more.

But there’s more to unpack here…

For example, you may wonder how much sleep is enough, how sleeping late, and how interrupted sleep all affect your muscle growth. So, read on, and we’ll address all of the above!

What’s Considered A ‘Lack of Sleep’?

Before we dive deeper into this topic, we need to establish how much sleep is NOT enough. Some men sleep 5 or 6 hours a day, so would getting their usual sleep be enough for actual gains?

No, 5 or 6 hours of sleep are only enough for a small percentage of the population. Anyone else will be prone to muscle loss, despite their efforts to eat healthy and push some serious weight.

Instead, you need to sleep 7 to 9 hours a night for maximum muscle growth and optimal health. Of course, if you train excessively, you’ll need more sleep than usual. That could be an hour or two, but it varies from one guy to the next.

Also, 7 to 9 hours of sleep is what most athletes need, but elite athletes should try to reach for 9 hours (and sometimes more!). Bodybuilders require the same amount of sleep as other athletes. And if you’re on an aggressive diet that might cause you to lose muscles, sleep can be a lifesaver, making up for the muscle mass you’re losing.

When cutting, you want to try and hold on to every ounce of lean muscle mass, and thereby maintain your strength. Nevertheless, it’s worth noting that genetic variations are at play here too. So, some people may need more or less sleep than average.

How Lack of Sleep Affects Muscle Growth:

When you don’t get enough sleep, your muscles aren’t allowed sufficient time to grow, due to the lack of muscle-building hormones we’ve detailed above. This means you won’t get the adequate energy needed to build muscle. But more than that, your muscle mass can decrease (even in caloric maintenance) if you don’t sleep enough.

To demonstrate, a 2011 study examined the relationship between sleep deprivation and muscle gain. It observed people who followed strict sleep schedules for 72 hours. They all adhered to a calorie-regulated diet. The only difference was that one group was allowed to sleep for 5.5 hours per day; the other had 8.5 hours of sleep per day.

Researchers found that the group who slept less had 60% less muscle mass, whereas the other group had 40% more muscle mass. So, these results are exactly how much sleep affects muscle growth!

Beyond this, when you sleep less, you’re more likely to eat more.

This is because your body reduces the amount of the hormone leptin, which makes you feel full. Instead, it increases secretion of the appetite-inducing hormone ghrelin, urging you to eat more. Needless to say, this will only make it more difficult for you to maintain a healthy diet, and consequently build muscle.

How Sleeping Late Affects Muscle Growth:


Your late nights may or may not affect your muscle building – and here’s how…

For one, if you sleep late and wake up early, you obviously aren’t getting enough hours of sleep. And we’ve detailed exactly how that can hinder your muscle growth.

Secondly, if you’re sleeping late at different hours each night, your irregular sleep schedule will be a problem. To illustrate, when you don’t have a regular sleep schedule, it disrupts your natural circadian rhythm, commonly known as the biological clock.

Since it monitors most bodily processes, your biological clock’s disruption can cause many complications, including ones relating to muscle gain and your overall workout/gym performance.

These second and third-order effects are the dangerous domino effect of sleeping late, not sleeping enough, or waking up several times in the night. And they will certainly affect your muscle growth and recovery.

But if you’re actually getting enough sleep and sleeping at a fixed time each night, you’ll fare better. There’s not much evidence to support the idea that your late sleeping hours alone will affect your muscle growth.

How Interrupted Sleep Affects Muscle Growth:

Of course, uninterrupted sleep is preferable…

But what if you wake up several times at night? Ultimately, what counts is whether you’ve woken up after a complete sleep cycle or not. So, if you wake up right after, your body won’t miss out on the benefits of good sleep and will recharge well.

Otherwise, if you wake up mid-cycle or when you’re in your deep sleep stage, you’ll probably feel exhausted in the morning. And you’ll see that reflected in your gym performance.

How One Night of Bad Sleep Affects Gains:

Believe it or not, one night of bad sleep can make all the difference. And the consequences go beyond feeling sluggish or out of it the next day.

In fact, a study published in the Journal Science Advance demonstrates that not getting your usual hours of sleep, promotes changes to your fat and muscle tissues. This causes the worst combination: muscle loss and weight gain. Accordingly, your body stores more fat, and your muscle tissue breaks down more muscles for energy.

And one bad night of sleep may or may not make a significant difference. Our writeup on fixing your sleep schedule tackles whether or not you should pull an ‘all-nighter’ to fix your sleep schedule.

If that one bad night of sleep follows a heavy workout, you’ll probably build less muscle, as we’ve mentioned earlier. But if it precedes your workout, your performance might take the hit instead.

Nevertheless, you can recover from a bad night’s sleep easily! Studies have shown that strategic napping can increase protein synthesis if done right.

For instance, you can take a nap the following day, or make it up the next night. But make sure that one night doesn’t turn into a week. Because that’s the negative compounding loop kicks in, and your muscle growth, energy levels, and even mood head downhill quick.

Final Words On Sleep Quality, Length & Muscle Growth

Ultimately, lack of sleep impacts your muscle gain and gym performance. So, if you don’t get 6 to 8 hours of sleep a night, you won’t reap the full benefits of your workouts.

In other words, your body won’t have sufficient time to break down glucose as an energy source. And your appetite hormones get negatively influenced. That is primarily what’s at stake here.

This leads to you not being energized before your workouts, swims, runs, or gym sessions. Also, the muscle-building hormone (HGH) is supposed to be at work when you’re asleep, enhancing your muscle recovery and growth. So, you’ll miss out on a lot if you don’t get a good night’s sleep.

Bottom line – get to bed on time or early, get enough hours, stay asleep for your full cycles, and STAY OPTIMIZED, Gent!


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