August 31


How Sleep Affects Muscle Growth

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Did you know the amount and quality of your sleep has a strong effect on your muscle growth? No, rest isn't for the weak. Adequate rest, recovery and sleep can help make you stronger, fitter and encourage muscle growth.


These days, we all lead busy lives with hectic schedules. Often, we may feel encouraged to sleep as little as possible so that we can achieve more during waking hours. Beware though, too much hustle makes it difficult to grow muscle.

Regardless of your diet, protein intake, supplement regime and training schedule, you won't reach your potential without proper sleep.

Below, we'll cover a few ways in which a good night's sleep is crucial for not only muscle growth, but your overall health and fitness.

How important is sleep for muscle growth?

In essence, sleep is crucial.

When it comes to muscular hypertrophy (a.k.a. muscle growth), any type of strength training can work.

too much hustle makes it difficult to grow muscle

Strength training works by breaking down muscle fibres at a microscopic level. Essentially, your body detects this breakdown of your muscle protein and attempts to repair the 'damage.' Cells grow, adapt and create new muscle strands. As a result, your muscles grow back bigger and stronger.

When does this muscle growth and repair take place? When you're  asleep.

Additionally, it's during your sleep that your body replenishes its glycogen stores. This glycogen is the fuel source your muscles use.

Naturally, when you work out, your body uses up glycogen. Therefore, if you plan of exercising again in the near future, you're going to want to do so with full glycogen stores.

Recovering well and getting sufficient sleep helps your body do this.

What does the research say about sleep affecting muscle growth?

If you train a lot, but don't prioritise sleep, you're working harder but not smarter. Ultimately, you may even be undoing some of your hard work in the gym by not sleeping enough each night.

Brazilian researchers tracked sleeping patterns of 2 separate groups of participants over the course of 3 days. One group were only allowed 5 hours 30 minutes sleep per night. The other were allowed 8 hours 30 minutes. What effect did that extra 3 hours sleep have on participants' muscle? After only 3 days, participants in the first group had 60% less muscle mass. Conversely, the second group who had more sleep showed 40% more muscle mass.

This suggests that inadequate sleep results in our body breaking down more muscle than it can build.

Furthermore, an Australian study took things a bit further. Researchers kept healthy young men awake for 5 consecutive nights and measured their performance during exercise. Results show restricted sleep has negative consequences on your body's ability to hold on to its muscle mass.

For muscle growth, how much sleep should I get?

On average, adults require between 7 and 9 hours sleep each night.

If you're looking to build muscle, or lose body fat for that matter, this number becomes more crucial.

Ensuring a good night's sleep is the best way to reap the benefits of your hard work in the gym.

I regularly sleep for just 6 hours per night, is that enough to build muscle?

No, not really.

If you're not making at least 7 hours of sleep every night, it's probably time to make rest a priority. It may sound counterintuitive, but you might find you get better results by sacrificing an early morning workout for an extra hour in bed.

Below, I've included some more tips and recommendations on how you can get more sleep.

Is it possible to track my sleep quality to ensure my body repairs its muscles properly?

There are several smartphone apps which attempt to measure the quality of your sleep. Likewise, many fitness trackers and wearables allow sleep monitoring and tracking.

Keeping track of both the quality and quantity of your sleep provides insights you may find useful.

Ensuring a good night's sleep is the best way to reap the benefits of your hard work in the gym

Following any strength training or hypertrophic workouts, see what proportion of deep sleep you get. The deeper you sleep, the more opportunity your body has for muscle growth and repair.

How can you get more sleep?

Although there are many ways we can improve our sleeping habits, there's one rule that stands out above all others.

Keep a regular sleep schedule.

If you go to bed at the same time every night, you'll essentially train your body to go to sleep at a certain time.

However, if you still struggle to regularly get a deep, restorative rest through the night, here are some more tips:

  • Ensure your diet is well-balanced and contains plenty of high-fibre foods
  • Avoid caffeine after lunch time
  • Cut back on your alcohol intake
  • Avoid high intensity training sessions immediately before bed. If possible, complete your workout 2 to 3 hours before you want to go to sleep
  • Use night mode on your mobile devices to help reduce blue light exposure
  • Create a comfortable, peaceful environment to support deep sleep
  • Consider relaxation exercises or a sleep meditation
  • Make sure you have a comfortable bed and supportive mattress
Paul Stokes Perth Personal Trainer Sports Nutritionist Group Fitness Instructor Massage Therapist

About the author

Paul Stokes

Paul Stokes BSc (Hons) is a Certified Personal Trainer, Accredited Sports Nutritionist, qualified Exercise to Music Instructor, Precision Nutrition coach, Massage Therapist and teaches 8 of the Les Mills Group Exercise programs.

He currently works in the Oil & Gas industry as a Wellness Coach, imparting his vast knowledge and experience to improve the quality of life of several hundred offshore workers.

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