Sleep Your Way to Fit: A Workout You Can Do with Your Eyes Closed

We all know that we should get a good night’s sleep. However, did you know that getting a good night’s sleep is a significant factor for getting into shape?

Sleep is often overlooked when it comes to fitness. Rest is a vital part of getting in shape, and, what’s more, it has a significant effect on your weight loss goals. Let’s take a closer look at sleep and the role it plays in getting fit and losing weight.

The Physiology of Sleep

Did you know we spend about a third of our lives asleep? We do. However, even though we spend so much of our time sleeping, few of us understand why or how it works. The physiology of sleep is something about which most people know little to nothing.

There are two types of sleep, non-rapid eye movement (NREM) and rapid-eye-movement (REM). When you are asleep, you are cycling between them.  NREM is the vast majority of your cycle, comprising 75 to 80 percent of your sleep, with REM taking the other 25 to 20 percent. [1]

Each sleep session is made up of cycles. Your first sleep cycle lasts around an hour and a half. After that, each sleep cycle lengthens to around 100 to 120 minutes each. Most of us have from four to five cycles in a sleeping period.[2]

While you are in the two types of sleep, your brain and body are reacting. During NREM sleep, there are four stages:[3]

  • Stage 1, Duration 1 to 7 minutes: Light sleep. It helps you transition into deeper sleep. Your brain wave activity changes in this stage from awake to asleep.
  • Stage 2, Duration 10-25 minutes, then gradually longer: Deeper sleep. This sleep stage is characterized by brain activity like that of the end of stage one. Some experts theorize that this is when memories are formed and consolidated.
  • Stage 3, Duration 3 to 8 minutes: Slow-wave sleep. Brain activity has changed from stage one and appears to occur in slower waves.
  • Stage 4, Duration 20 to 40 minutes: Slow-wave sleep. Brain activity is much the same as Stage 3, but it is a much deeper sleep, meaning it is difficult to wake up during this stage.

REM sleep has brain wave activity similar to stage 1 and 2, but also muscle slackness and quickly-moving eye activity. It is short at the beginning of a sleep session but prolongs as it progresses. This stage is typically responsible for your dreams.[4]

In addition to the changes in brain waves and activity, the systems in the body react as well. Your blood pressure and heart rate change, as well as the levels of activity in your sympathetic nervous systems. Your breathing varies, as does the blood flow to the brain, and your kidneys slow down operation. [5]

However, perhaps the most pertinent thing that happens during sleep associated with your physical fitness is with the endocrine system or your flow of hormones. Growth hormones, thyroid hormone, and melatonin are affected by your sleep. Thyroid and melatonin induce you to feel sleepy and are what influence you to go to bed. However, the growth hormone is what helps repair and build muscles, which is essential when you are getting into shape. [6]

Recovery and Sleep

When you exercise, you need to replenish your fluids, rest, and recover afterward, called Short-term recovery.  Also known as active recovery, short-term recovery is essential to improving your performance and a crucial factor in injury prevention. [7]

Per, when you don’t get enough sleep between workouts, you could experience:[8]

  • Longer bouts with sore muscles
  • Moodiness
  • Stress
  • Decreases in glucose processing
  • Better physical endurance
  • Increases in how much exertion you feel you are making while exercising

As you can see, sleep is a vital part of your short-term recovery, especially quality sleep where the growth hormone is released. As we mentioned, this hormone aids in muscle building. However, the growth hormone is also critical for bone building and one other important fitness goal: fat burning.[9]

Losing Weight While You Sleep

Many people want to lose weight. So, they exercise and try to eat nutrient-dense foods. However, if they aren’t getting enough sleep, they might not have the success they otherwise would.

Top Fitness Magazine suggests that the amount of sleep you get will affect how you eat and your success at losing weight. Not only do people who are sleep deprived weigh more than those who sleep enough, but they also struggle to lose weight. [10]

There are physical challenges as well. Sleep deprived endocrine systems produce more of the hunger hormones (leptin and ghrelin), which can lead to overeating. People that consistently get too little sleep can also have problems with their glucose and insulin levels, much like people who have diabetes. In the long term, sleep deprivation is a contributing factor to diabetes. [11]

Finally, sleep deprivation can make it harder for you to do the right thing. When you are tired, you aren’t as diligent about making healthy choices. Also, you cannot work out with the same intensity you can when you are well-rested.

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[1] Institute of Medicine (US) Committee on Sleep Medicine and Research; Colten HR, Altevogt BM, editors. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Washington (DC): National Academies Press (US); 2006. 2, Sleep Physiology. Available from:

[2] “Stages of Sleep and Sleep Cycles.” 19 December 2018. Web. 8 April 2019. <>.

[3] Ibid.

[4] “What are REM and Non-REM Sleep?” 26 October 2018. Web. 8 April 2019. <>.

[5] “What Happens When You Sleep?” Web. 8 April 2019. <>.

[6] Institute of Medicine (US) Committee on Sleep Medicine and Research; Colten HR, Altevogt BM, editors. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Washington (DC): National Academies Press (US); 2006. 2, Sleep Physiology. Available from:

[7] Rodriguez, Julia. “How Does Sleep Affect Exercise Recovery?” Web. 8 April 2019. <>.

[8] Ibid.

[9] Ibid.

[10] “Why Sleep is Important for Weight Loss.” Web. 8 April 2019. <>.

[11] Ibid.