A Comprehensive Guide to Sleep for Fat Loss and Muscle Growth

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Sleep is that golden chain that ties health and our bodies together.
––Thomas Dekker

​I’m sure this will come as a shock, but, when you don’t sleep well, life sucks.
 
What you may not know and what’s worse by far (let’s get our priorities straight here), is that your gains will suffer.
 
You could have the best training program and diet in the world, but, if your sleep is inadequate, you’re going to struggle with:
 

• Losing fat
• Gaining muscle
• Improving training performance

 
Yes, that’s basically everything.
 
Fortunately, improving sleep is easy, cheap, and more anabolic than expensive supplements, pre-workout formulas, and other less useful yet “sexier” fitness tools.
 
So don’t sleep on this low-hanging fruit. (See what I did there?)
 
Keep reading for a comprehensive guide on:
 

• The benefits of sleep on your gains
• The negative effects of inadequate sleep
• What “good sleep” is
• Practical tips to improve sleep
• Sleep supplements

 
Let’s delve into it.

The benefits of sleep on your gains
 
The most direct benefit is the fact that the bulk of your recovery from exercise takes place when you’re asleep.
 
Whilst training provides your muscles with a hypertrophic stimulus – the stimulus to increase in size – the recovery process enables muscle growth to happen.
 
If you’re not recovering, you’re not growing.
 
The second direct benefit of sleep is that it makes it easier to adhere to a fat loss diet.
 
For example, this study on women with overweight and obesity showed that 7 hours of sleep per night or more and the subjective feeling of having slept well (called “subjective sleep quality” by the authors of the paper), increased the subjects’ weight loss success rate by 33%.
 
The researchers defined “weight loss success” as losing 10% of bodyweight or more. That’s a whopping 20 lbs for a 200 lb person!
 
Not only that: in the same study, the same sleep duration and sleep quality were also associated with a greater chance of maintaining weight loss 12 and 18 months after achieving it.
 
Finally, sleep can contribute to your gains in a number of indirect ways, too.
 
First of all, it’s necessary for optimal physical health, which in turn is essential for optimal physical performance.
 
For instance, as you progress through the various stages of sleep, your heart rate and breathing undergo changes that can promote cardiovascular health.
 
Adequate sleep can also help prevent or recover from illness.
 
Lastly, sleep enhances cognitive processing and function, mood, and mental health.
 
If you’re in the right headspace for it, it’s much easier to find the motivation and drive to stick to a training plan and nutrition program.
 
The negative effects of inadequate sleep
 
Now, onto the bad news. Unfortunately, there’s a lot of it.
 
According to research, insufficient sleep makes it harder to:

• Lose body fat
• Not lose muscle whilst dieting
• Not overeat and regain fat after losing it
• Build more muscle

 
How can inadequate sleep impact fat loss?
 
Inadequate sleep is the enemy of anyone who’s trying to lose fat and keep it off, but don’t get confused: sleep can’t change the laws of thermodynamics.
 
In other words, if you’re in a caloric deficit (when you’re burning more calories than you eat, which results in fat loss over time), you’re going to lose weight.
 
However, inadequate sleep can affect your hormones, your brain, and your metabolism. These disruptions can have a knock-on effect, making it much more challenging for you to maintain the discipline and healthy habits needed to lose fat and build muscle.
 
A chronic lack of sleep can have the following consequences:

1. It can increase ghrelin, which is a hunger hormone, and lower leptin, which is a satiety hormone (click).
 
As a result, not only will you feel hungrier than usual; you’ll also struggle to feel full eating what would normally be a satisfying amount of food. Talk about a double whammy.

2. It seems to activate certain regions of the brain that make you more likely to overeat.
 
For example, this study recruited 30 men and women, with a BMI score within the “normal weight” range, to undergo two different experimental phases. 
 
In one phase, the subjects spent 4 hours in bed for 6 days; in the other phase, they spent 9 hours in bed for 6 days.
 
When the researchers compared the differences between the two phases, they found that, when spending only 4 hours in bed, the subjects became more sensitive to food stimuli and got a greater sense of reward from eating.
 
Add these two outcomes to increased ghrelin and lower leptin, and you’ve got yourself a recipe for potential over-eating.

3. It can affect your food preferences… for the worse.
 
Sorry to break it to you, but sleep deprivation doesn’t make you want to eat more protein and vegetables. In fact, it seems to increase your desire to eat high-calorie foods that tend to contain a lot of carbs and fats. Not exactly recommended diet staples when you’re trying to lose fat…
 
Moreover, if you aren’t sleeping enough, you also have more time on your hands to give into these heightened cravings.

4. It can disrupt your circadian rhythms and metabolism.
 
There are different natural rhythms that contribute to the smooth running of every organism, including the human body.
 
Circadian rhythms repeat themselves roughly every twenty-four hours, carrying out important processes. An example of a circadian rhythm is the sleep–wake cycle.
 
Your metabolism is the process by which your body converts food into energy and expends that energy on essential physiological functions like breathing, exercise, and non-exercise activity.
 
Disrupting your circadian rhythms – for example by not having a consistent sleep pattern – can in turn affect your metabolism and thus your ability to manage your weight and body fat levels.

5. It can make you feel more tired, so you’re less likely to exercise.
 
Energy balance, which regulates your bodyweight, has two components:

• Energy intake, or the food that you eat
• Energy output, or the calories you burn with physical activity

 
The combination of eating more and moving less creates a state of positive energy balance (in which you’re eating more calories than you burn), which results in fat gain over time.
 
How can inadequate sleep impact muscle gain?
 
First, how difficult is it to gain or maintain muscle when you’re in a caloric deficit? Well, it’s actually easier to lose muscle than to gain it.
 
As an example, this study compared two interventions.
 
In one intervention, the participants were assigned a personalised diet, designed to induce a moderate caloric deficit, and spent 8.5 hours in bed every night for 14 days. In the other intervention, over the same 14-day period, they had the same diet, but only spent 5.5 hours in bed every night.
 
Both interventions caused a similar amount of weight loss… but, when spending only 5.5 hours in bed, 60% of that loss came from fat-free mass, which includes muscle mass! On the other hand, only a quarter of the weight loss in this intervention came from fat mass.
 
On the other hand, how hard is it to build muscle when you’re eating at maintenance or in a small caloric surplus?
 
Even if you weren’t in a caloric deficit, inadequate sleep could still thwart your muscle-building efforts in two major ways: it can reduce muscle protein synthesis and change your hormonal environment by increasing cortisol (the stress hormone) and lowering testosterone (an anabolic, or muscle-building, hormone).
 
If you’re a cis man or a gender-non-conforming person taking exogenous testosterone for medical reasons, you may not need to worry about testosterone, but you can still experience a drop in muscle protein synthesis and feel the deleterious effects of heightened cortisol levels.
 
These changes can promote a physiological state known as catabolic, in which your body is more likely to lose muscle rather than build it.
 
Moreover, when you’re always tired, your training performance is going to suffer.
 
As I mentioned, training is the most potent driver of muscle growth. Therefore, if your sessions suck, so will your gains.
 
Don’t panic!
 
I understand you’ve just read 1000 words of doom, but I don’t want you to start worrying about losing muscle if you get a night of bad sleep once in a blue moon.
 
You don’t need perfect sleep all the time.
 
You need pretty good sleep most of the time.
 
The point of this article isn’t to scare you.
 
It’s to encourage you not to underestimate the benefits that the sleep-improving strategies I’m going to suggest can have on your physique and training performance.
 
How much sleep is “enough”
 
In general, according to the Sleep Foundation, most adults need 7 to 9 hours of good quality sleep per night.
 
However, these guidelines are based on averages, so think of them as a starting point, not as a set of hard and fast rules. To define your optimal sleep duration, consider how many hours of good sleep you need to feel rested and ready for the day when you wake up.
 
As a rule of thumb, the more active you are, the more recovery you’re going to need, so you may find that 8 to 10 hours is your sweet spot to accomplish all of the above.
 
On the other hand, if you’re more sedentary, you may be able to feel your best with only 6 to 7 hours of good sleep.
 
Practical tips to improve sleep

1. Develop a consistent sleep schedule, going to bed and waking up at relatively similar times every day, including weekends.

2. Ensure your room is a comfortable temperature (not too cold and not too hot), dark, and quiet.

3. Create a stress-relieving pre-bed routine: writing your to-do list for the next day, journaling, reading, stretching, or meditating are all examples of activities that can help you wind down.

4. Stop looking at screens 30 to 60 minutes before bed to reduce the negative impact of artificial light (blue light) on the release of melatonin, the hormone that helps you fall asleep.

5. Avoid eating less than an hour before bedtime.

6. Avoid stimulants in the afternoon and evening. For example, the half-life of caffeine seems to be around five hours (click), which means that you still have half of that caffeine dose in your system five hours after taking it!

7. You could consider wearing blue light-blocking glasses, although the evidence on their effectiveness is mixed.

As a personal anecdote, I’ve been wearing them at night for so long that my brain now associates them with my bedtime. So, whether they’re effective to block blue light or not, I start getting sleepy when I put them on. The placebo effect can be powerful!

8. If you’re missing out on sleep at night, short naps of less than 30 minutes can improve alertness, concentration, and your ability to perform.

​You may not want to nap for longer than 30 minutes to avoid “sleep inertia”, or feeling groggy when you wake up, which can happen when you get into the deeper stages of sleep by napping for too long.
 
Sleep supplements
 
Before you consider a supplement, do your best to implement lifestyle changes first. They’re free and generally more effective.
 
However, sometimes life is so hectic that lifestyle changes aren’t possible, and supplements can be a useful short-term solution to help you sleep better.
 
The following is a list of supplements with the best evidence base that I’m aware of.
 
I encourage you to check the available scientific literature and the best dosage for each one by looking them up on the website Examine.com, so you can make an informed decision before you start taking any.
 
These substances can help with three distinct problems:

1. Struggling to fall asleep
2. Struggling to feel well-rested after sleeping
3. Struggling with excess stress and a restless mind

 
Supplements to consider if you struggle to fall asleep

• Melatonin

 
Supplements to consider if you struggle to feel well-rested the next day

• Glycine
• Rhodiola rosea

 
Supplements to consider if you struggle with excess stress and a restless mind

• Ashwagandha KSM-66
• L-Theanine
• Valerian

 
Practical takeaways

1. Adequate sleep is necessary to build muscle and recover from training. It’s also proven to improve fat loss results. On the other hand, insufficient sleep makes it harder to lose fat, gain muscle, and maintain muscle mass during a diet.
2. What “enough” sleep is, varies between people. As a rule of thumb, try to get 7 to 9 hours of good sleep per night.
3. To improve your sleep, go to bed and wake up at similar times most days; sleep in a dark, quiet, cool environment; develop a stress-relieving pre-bed routine; stop looking at screens 30 to 60 minutes before bed; avoid eating and taking stimulants like caffeine too close to bedtime; consider wearing blue light-blocking glasses; and take naps of less than 30 minutes to make up for lost sleep.

 
Thanks for reading. May you make the best gains.
 
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References:
 
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