Sleep is essential for both physical and mental health. The Journal of the American Medical Association calls sleep deprivation an "endemic" in modern societies. Too much or too little sleep are both linked with increased risk for mortality, hypertension, diabetes, and obesity.
When it comes to muscle health, whether you're trying to build lean muscle mass, maintain your current muscle mass percentage, or prevent the loss of it, sleep should be a priority. Sure, you work hard to plan your meals and snacks right, stick to your workout routine, and supplement your diet with the needed nutrients. However, don't underestimate the role of adequate quality sleep on muscle health and growth.
THE LINK BETWEEN SLEEP AND MUSCLES
For one thing, poor sleep means poor energy. How will you be able to give it your all during your workouts or not tire out early into them? Also, a lack of sleep can increase the chance of an injury during exercise. There's more to it than energy levels, though. It's also about hormone balance. We need more than just protein to build muscles. We need the right balance of hormones. During sleep, the body is in REPAIR and REBUILD mode. On the one side, during sleep, your body releases anabolic ("building") hormones, such as IGF-1, human growth hormone, and testesterone. Yep, these are definitely involved in muscle-building. Interfering with proper sleep interferes with the rate that these hormones are released. On the other side of the balance, sleep reduces levels of catabolic ("muscle breaking") hormones, such as cortisol. Poor sleep will also interfere with this process, which sets the stage for muscle protein breakdown. Clearly, proper muscle repair and growth occur with normal, routine deep sleep patterns. Sleep can also interfere with the balance of hormones related to your appetite. Poor sleep can increase levels of ghrelin (which stimulates appetite) and lower levels of leptin (which increases feelings of satiety). That's not going to help much with keeping cravings under control, now is it? Too little sleep is even linked with increased inflammation, which can decrease muscle strength.
When we think muscle health, it goes beyond athletic performance, though. Sleep deprivation's muscle-damaging effects prevent muscles from recovering from exercise but also from injuries or certain conditions associated with muscle mass loss, such as sarcopenia (the gradual loss of muscle mass, especially seen in the elderly).
THE SCIENCE
One study on more than 10,000 university students studied the effects of sleep quality and duration on handgrip strength. A link between sleep quality and muscle strength was seen in men - men with 6 or less hours of sleep had poorer muscle stegnth than those who slept for 7-8 hours.
The Journal of Science and Medicine in Sport analyzed several research studies and concluded that inadequate sleep impairs building maximal muscle strength with resistance exercise.
One study examind the effects of a one-week sleep restriction on testesterone levels in men. Levels were decreased by 10-15% in men who underwent a sleep restriction of 5 hours per night. For the sake of comparison, as a part of normal aging, testesterone levels in men typically decrease by 1-2% per year. Notice how much greater the drop is simply due to sleep restriction.
THE GOAL
The National Sleep Foundation (NSF) advises healthy adults to get 7-9 hours of sleep each night. These recommendations were created by an expert panel of people from different fields of science and medicine that reviewed hundreds of validated research studies on sleep duration and health. Other sleep organizations, such as the American Academy of Sleep Medicine (AASM) and Sleep Research Society (SRS) have recommendations that closely resemble the NSF's recomendations.
THE PLAN
Need more sleep? Not measuring up to the NSF's recommendations? Perhaps some of the following tips will help you fall asleep, stay asleep, and improve your sleep hygiene:
+ Limit high-intensity activity up to 3 hours before bedtime. Less active, relaxing activities to engage in closer to bedtime include reading, walking, listening to music, or taking a warm bath.
+ Maintain consistent sleep and wake times
+ Have a serving of protein before bed
+ Choose foods rich in tryptophan closer to bedtime - bananas, dates, figs, grapefruit, oatmeal, pumpkin seeds, tuna, turkey, and yogurt.
+ Avoid alcohol or caffeine up to 6 hours before bedtime
THE BOTTOM LINE
It may not sound as sophisticated as some supplements, diet plans, and training routines out there but we can't emphasize it enough - sleep is important even for muscle gains!
Adequate sleep means adequate muscle repair and growth. Poor sleep can actually mean muscle loss. So, instead of constantly thinking what we could be doing instead, get a good night's sleep! Sweet dreams!
REFERENCES
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Leproult, R., & Van Cauter, E. (2011). Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA, 305(21), 2173–2174. https://doi.org/10.1001/jama.2011.710
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