How To Sleep For Muscle Growth & Fat Loss


Sleep is possibly one of the least sexy topics within health and fitness.

Everyone wants to focus on what to eat, when to eat, how to train, and what program to do...that’s the fun stuff! 

But here's the problem most people encounter... sleep is such an important part of health and fitness, you'll struggle to make any progress if you neglect it.

In today's blog, you'll learn how to maximize your sleep to build more muscle, burn more fat, and improve your health.


Poor sleep is associated with an increase in metabolic syndrome.  

Mayo Clinic defines metabolic syndrome as... 

“A cluster of conditions that increase the risk of heart disease, stroke, and diabetes."

Metabolic syndrome includes high blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol levels. The syndrome increases a person's risk for heart attack and stroke.


There are two types of sleep: 

1. REM

2. Non-REM

You cycle through these throughout the night, but start the night in non-REM sleep, which itself has four stages: 

STAGE 1: Between awake and falling asleep.

STAGE 2: Light sleep. Heart rate and breathing regulate and body temperature drops. 

STAGE 3 & 4: Deep sleep. 

From here, you move into REM sleep (rapid eye movement sleep) where you become temporarily "paralyzed", start dreaming, etc.

You will cycle through these stages 3-4 times in a night of sleep. 

During sleep, your body does a lot of amazing things: 

→ Your brain processes and stores into memory the events of the day. 

→ Your pituitary gland releases growth hormone that helps your body and muscles grow and repair (more on this later.) 

→ You go into a parasympathetic nervous system state. That means cortisol is lowered until it’s time to wake up, and blood pressure goes down. 

→ You release cytokines, small proteins that lower inflammation.  This is part of why sleep is so important to fight off infection, illness, or injury. 

While sleep is massively important for health, it’s also a really important factor in your physique development. There is a lot of evidence that suggests more sleep (to a point) = more gains and less body fat, because...

→ Glycogen is replenished during sleep

Glycogen is the storage form of carbohydrates.  When you eat carbohydrates, your blood glucose levels rise, then are stored within the muscles or body fat cells.  The more of that carbohydrate that gets stored as glucose in the muscle, the harder you are able to train. 

→ Strength is improved after getting good sleep.  

Increased IGF-1 is associated with improved sleep quality, and is rapidly reduced during periods of poor sleep.  IGF-1 is an anabolic hormone that plays a role in protein synthesis. 

→ Cortisol is higher when you don’t get adequate sleep.  

Cortisol is a stress hormone and is catabolic, meaning it breaks down muscle tissue.  Having chronically high cortisol for long enough can cause high blood glucose, suppressed immune system, and high blood pressure.  Getting plenty of sleep will help keep cortisol levels down. 

→ Growth hormone is released during sleep.  

Growth hormone will help you grow, repair and preserve muscle mass, as well as repair tissue in the brain and other organs. 

→ Lack of sleep causes an increase in the release of the hunger hormone grehlin.  

If you aren’t getting adequate sleep, you will find yourself getting more hungry over the course of the day, and have an increase in cravings.  Poor sleep also lowers leptin, which is the “fullness hormone” and plays a role in fat burning. 

A study done in 2018 divided almost 17,000 participants into groups of people who slept <5, 6, 7, 8, and >9 hours per night, with 7 hours/night being the control group.   

The participants’ body composition was measured with DEXA scans, and while we know DEXA and other body fat scans are highly inaccurate, over this many participants we can assume it would give at least a relatively accurate picture of the different trends of body fat levels between groups.  

The researchers concluded... 

“The results of our study suggest that short sleep hours might be associated with an increase of fat mass, general obesity and abdominal obesity, whereas long sleep hours [>9] might be related to a decrease of lean mass in Korean adults aged between 18 and 70 years. Adequate sleep hours may be necessary for the prevention of obesity and maintaining a balanced body composition.” 

But my favorite study on this topic is titled...

Insufficient sleep undermines dietary efforts to reduce adiposity

This study was done in 2010 over a 2-week period. Participants were placed in two groups:

GROUP 1:  8.5 hour sleep group

GROUP 2: 5.5 hour sleep group 

The goal?

Determine whether sleep restriction slows the effect of a reduced-calorie diet on excess body fat.  

The researchers measured loss of fat and lean tissue. They also measured changes in substrate utilization (the use of fat and carbohydrate by the body for energy), energy expenditure (calorie burn), hunger, and 24-hour metabolic hormone concentrations.

The result: 

“Sleep curtailment decreased the proportion of weight lost as fat by 55% (1.4 vs. 0.6 kg with 8.5 vs. 5.5 hours of sleep opportunity, respectively; P = 0.043) and increased the loss of fat-free body mass by 60% (1.5 vs. 2.4 kg; P = 0.002). This was accompanied by markers of enhanced neuroendocrine adaptation to caloric restriction, increased hunger, and a shift in relative substrate utilization toward oxidation of less fat.” 

TRANSLATION - The people who only slept 5.5 hours per night lost about 2 pounds less fat in 2 weeks, but lost 2 pounds more lean mass (not the type of weight you want to be losing!) They also started adapting hormonally to calorie restriction (down-regulating calorie output to adapt to the restriction), were hungrier, and burned less fat for fuel.

When dieting we’re generally doing everything we can to burn the highest amount of body fat and preserve the most muscle mass possible, so these are the exact opposite results of what you’d hope for on a fat loss diet. 

Another similar study in 2018 had overweight and obese participants divided into two groups for 8 weeks:

GROUP 1: Just restricted calories

GROUP 2: Restricted calories and sleep.  

Both groups ate 95% of their measured resting metabolic rate, and the sleep restricted groups were instructed to reduce sleep 5 nights a week, and slept as much as they wanted the other two nights.  

The sleep restricted group lost the same amount of weight as the calorie restriction only group, but the sleep restricted group lost a larger proportion of their weight from lean mass.  The sleep restricted group also saw greater decreases of leptin. 

This study seems to show that getting poor sleep increases loss of lean tissue, and causes you to experience more hunger and less fullness. 

Now, aside from the effect directly on hormones, there are more basic implications from not getting great sleep.  

We know non-exercise activity thermogenesis (NEAT) is the biggest proportion of total daily energy expenditure (TDEE), aside from BMR, which isn’t under our control. 

When you aren’t getting enough sleep, you are more tired during the day (duh, right?).  

Well, if you are more tired you are much less likely to move around as much.  You might fidget less, not go check the mail that day, sit instead of stand, and so on. All of this "non-exercise movement" makes up the N.E.A.T. or non-exercise activity thermogenesis component of metabolism shown above.

According to Mayo Clinic researcher Dr. James Levine, N.E.A.T. can cause a variance in TDEE by up to 2000 calories per day in different people of equal body size.  

That’s a massive difference.  You probably won’t have a swing of 2000 calories in your N.E.A.T. from getting a bad night’s sleep, but it can definitely put a damper on your movement and cause a decrease in your calories burned for just that reason alone. 

Other downstream effects of lethargy from poor sleep could be snacking just to feel a boost even in the absence of excess hunger, missing training, or overall feeling unmotivated.


There are a lot of actions you can take to improve your sleep duration and quality, and it can start the minute you wake up.  

Our bodies work on a body clock called your circadian rhythm.  A lot of your body’s systems work on a 24-hour clock, including your sleep hormones, cortisol, blood pressure, blood sugar, and many others. 

SLEEP KEY #1: Getting Sunlight Early

Starting your day by getting into the sun can help “set” your circadian rhythm to be awake with the sun and asleep when the sun goes down.

Melatonin is the hormone that tells your body it’s time to sleep, and it works on a cycle of low in the daytime and high in the evening/throughout the night.  

Getting sunlight helps lower melatonin when it should be low, which in turn helps your body elevate melatonin when it should be elevated, which helps you fall asleep.

SLEEP KEY #2: Turning Screens Off 

The flip side of getting early sunlight is turning screens off at night, ideally about an hour before bed-time.  

The blue light emitted from screens on your TV, computer, or phone can mimic sunlight and suppress melatonin which makes it harder to fall asleep, and get good quality sleep once you do fall asleep. 

SLEEP KEY #3: Journaling 

Journaling, specifically a brain-dump journal can help you clear your head so you can fall asleep easier.  

This is especially helpful if you are someone who lays awake with racing thoughts or to-do lists in your head.  

Brain-dump journaling helps you get all those thoughts out onto paper so you aren’t stewing over those things or worried you’ll forget something by morning.  

To do a brain dump journal you will use a blank sheet of paper (No structured journal prompts needed) and literally just write out everything that comes to mind.  Get all your thoughts out (dump your brain) onto the paper so that you can fall asleep. 

SLEEP KEY #4: Meditation/Deep Breathing 

Your autonomic nervous system has two branches: sympathetic and parasympathetic.  

The sympathetic branch is also known as “fight, flight, or freeze” and is the amped-up, more stressed state.  

Cortisol is higher in this state.  Cortisol works opposite to melatonin.  When cortisol is up melatonin is suppressed, and vice-versa.  Parasympathetic is your “rest and digest” state.  

You are more calm, and heart rate and blood pressure lower in this state.  In order to get to sleep you need to be in the parasympathetic nervous state.  Meditation and deep breathing are tools to take you from sympathetic to parasympathetic.   

Meditation can be intimidating for some people who haven’t tried it before, so we recommend a guided meditation app that will take you through a session.  

Some great options: 


→ Headspace 


Deep breathing is another tool to switch you into a parasympathetic state.  

I recommend 4/4/8 breathing: 

1. Inhale for 4 seconds

2. Hold for 4 seconds

3. Exhale for 8 seconds.  

4. Repeat the above 8-10x.  

Inhaling increases your heart rate, and exhaling slows down your heart rate, so taking longer exhales than inhales will slow down your heart rate and help you get into a restful state to fall asleep. 

SLEEP KEY #5: Stay Out Of Bed, Until You're Ready For Bed

If you are working or eating in bed you will set up an association with your bed that isn’t sleep. When you only get into bed to sleep, your body starts to get tired in response to being in bed.  If you’re working you could associate bed with stress or other thoughts. 

SLEEP KEY #6: Create a Bedtime Routine 

You can create a “habit” of falling asleep by creating a bedtime routine.

Our bodies like habits.  It’s why you get hungry at the same time you normally eat lunch if you miss it.  It’s part of the circadian rhythm... your hormones can get on a schedule.  

So if you create a routine and do it consistently before bed, eventually you will start to get tired at that time of night in response.  

You can put together any of the previously mentioned tools, or add any of your own that you think would be helpful. Make sure it’s a solid routine but also short enough you can follow through consistently.  

A good routine might look something like:

→ Cup of decaf tea 

→ Journal 

→ Skincare 

→ Deep breathing in bed 

→ Sleep 

SLEEP KEY #7: Get to Bed Earlier 

If your main problem is not getting to bed on time, you will need to get to bed earlier in a step-wise fashion.  

Trying to make your bedtime two hours earlier all at once will mean you just lay there awake for at least that two hours, because your body is on it’s clock and used to being up doing things at that time.  

A good rule of thumb is to get to bed about 15 minutes earlier every 1-2 weeks.  It will take longer to get to the desired bedtime but it will gradually accustom your body to the earlier sleep time. 

Sleep could one of the major factors keeping you from your goal physique. If you think you could be leaving gains on the table by missing sleep give some of these tips a try - they'll help. 

If you're ready to be coached 1-1 by our team to your best physique ever, click here now to apply for online coaching with our team.

ABOUT THE author

Andrea Rogers is a certified nutrition coach, personal trainer, and coach for BairFit. Follow her on Instagram for more helpful training & nutrition content.

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