Building muscle and toning up requires a tremendous effort. You need to go through a host of lifestyle changes to sculpt that six-pack you dream about. Dieting and working out are usually emphasized as two major components of successful weight loss and accelerated muscle growth, and rightly so. You obviously can’t achieve your goals without making adjustments in your eating habits and continuously killing yourself in the gym. One basic yet crucial aspect that falls by the wayside far too often is sleep. How are sleep and muscle growth connected? Is 6 hours of sleep enough to build muscle? Follow the article to sort out all the effects of sleep on your body, and find your optimal sleep duration.
Why Do People Sleep?
It might be obvious that sleep is incredibly important for human beings. After all, most people feel dead on their feet just after a couple of sleepless nights. The mystery of sleep has been on the radar of many scientists for centuries, and even now the disputes are not settled. Here are some scientifically reliable (and questionable) ideas on why sleeping enough is so crucial for humans (11).
One of the earliest scientific theories about sleep is that it gave animals an evolutionary advantage. Staying still and quiet rather than active in certain periods saved them from an early death. That is, sleeping at night was safer than strolling through the wild when all the predators are hunting. This way, sleep was considered a key survival factor that kept animals safe when they were particularly vulnerable. Through natural selection, this strategy, as was argued, evolved into what humans now call «sleep».
A simple but true counter-argument here is that it is much safer to stay alert rather than unconscious when the danger is approaching you. When somebody is trying to break into your house and steal your belongings, you can react faster and more efficiently if you’re lying on a sofa awake, not asleep. So, it seems to be little advantage for anyone to sleep if safety is given top priority.
Energy Conservation Theory
Although it may be less obvious to people living in societies in which food sources are abundant, one of the strongest factors in natural selection is competition for and effective utilization of energy resources. The energy conservation theory argues that the main function of sleep is to reduce an organism’s energy demand and consumption at the times when it is least effective to search for nourishment.
Energy metabolism is notably reduced during sleep. For instance, both body temperature and caloric demand decrease during sleep, as compared to the state of wakefulness. Evidence like this supports the statement that the central function of sleep is energy conservation.
Another powerful explanation of the necessity of sleep is based on the long-held belief that sleep in some way restores what was lost during the periods of activity. Sleep provides a possibility for the body to repair and revitalize itself. The most striking of evidence gathered in support of this theory is that animals deprived of sleep entirely lose all immune function and die in a couple of weeks. This is further supported by findings that many of the central repairing functions in the body like muscle growth, tissue repair, protein synthesis, and growth hormone release happen mostly, and in some cases exclusively, during sleep.
Other rejuvenating functions of sleep are related to brain and brain function. For instance, while people are awake and going about their business, neurons in the brain produce adenosine, a by-product of the cells’ activities. The build-up of adenosine in the organism’s brain is thought to be one factor that leads to people’s perception of being tired. Interestingly, caffeine works by blocking adenosine in the brain, so that you don’t feel like you need a nap right now. Scientists argue that this build-up of adenosine during wakefulness may produce the “drive to sleep.” As long as we are in a state of wakefulness, adenosine piles up and remains high. When asleep, the body gets a chance to get rid of excess adenosine, so that people feel more alert when they’re awake.
As you can see, sleep directly affects your cognitive performance as well as muscle growth. Here is some more evidence regarding sleep and its effect on our muscle-building process.
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How A Lack Of Sleep Affects Muscle Growth
Believe it or not, sleep may be the exact reason why others seem to progress at a much faster pace than you are. Or why you simply aren’t seeing the results you were hoping for despite putting in the work.
Disrupting Hormone Secretion
As it was already mentioned, sleep helps you build up muscle through the release of growth hormone during stage three sleep, which is considered to be the deepest stage of sleep (8, 4). That is how sleep helps you build muscle. When humans are deprived of enough sleep, the normal sleep cycle is disrupted, which negatively affects growth hormone release. You may think that sleeping for just five hours is fine, but it will cause a severe decline in growth hormone secretion. A growth hormone deficiency, in turn, may result in the loss of muscle mass and have a negative impact on your ability to exercise. After all, it is really hard to crush your workout and stay focused when you’re completely exhausted.
Also, when you’re sleep-deprived, your body begins to overproduce ghrelin, the hunger-promoting hormone. Conversely, the levels of leptin, the hormone that signals satiety, are decreased. This can cause you to eat more calories (especially in the form of junk food) leading to an increase in weight and a possible decrease in muscle mass (10).
Finally, one study showed that a week of sleep deprivation in otherwise healthy young men resulted in decreased testosterone levels and significantly increased spikes of cortisol, a stress hormone (3). Furthermore, cortisol levels may stay elevated until the following evening if you don’t get enough sleep. Given that testosterone is an anabolic hormone that is crucial for muscle growth, and elevated cortisol can lead to fat storage and weight gain, the lack of sleep is shown to negatively affect your performance in one more way.
Preserving Fat And Losing Muscle
It’s not only that getting enough sleep helps your muscles grow. Without adequate sleep, muscle mass in fact decreases.
A study in 2010 examined how sleep deprivation affected muscle growth and recovery (5). The researchers studied individuals who were on a strict sleep schedule for 14 days. During this time, one group was allowed just 5.5 hours of sleep per night, which is a frequent case among Americans; while another was allowed 8.5 hours per day, which is within the range of what is usually recommended. All participants followed a calorie-regulated diet. As expected, all participants lost the same amount of pounds when equated for their calorie deficit.
The striking discovery was that the individuals who slept only 5.5 hours lost 55% less fat and 60% more muscle at the end of the study, compared to those who slept 8.5 hours.
A 2018 paper (1) found similar results analyzing the effects of just one night without sleep on 15 young men.
The muscles in their bodies showed signs of elevated protein breakdown, while their fat tissue displayed increased levels of proteins and metabolites that are involved in promoting fat storage. So, sleep has a striking effect not only on muscle growth but also on fat loss and accumulation.
Is 6 hours of sleep enough to build muscle? As you can see from this research, it clearly isn’t.
Glucose is a type of sugar that is stored within your body and used as an energy source. It is, in fact, the only kind of sugar that the body can break down for energy supply. Any other kind of sugar that we consume is converted into glucose before our muscles can make use of it.
During sleep, blood glucose gets stored in the muscle in the form of muscle glycogen. While glucose exists in other locations in the body, for example, blood or liver, muscle glycogen is the best location because it is close to where the energy will eventually be used.
When people are sleep-deprived, they don’t get maximum replenishment of muscle glycogen, which negatively affects their athletic performance. For example, one study concluded that sleep loss and associated reductions in muscle glycogen and perceptual stress reduced sprint performance and slowed pacing strategies during intermittent-sprint exercise for male team-sport athletes (6).
How Much Sleep Do You Need To Build Muscle?
Is 6 hours of sleep enough to build muscle? No way. You should try to get between 7 to 9 hours of sleep every night in order to maximize muscle growth and support your health. And no, napping can’t be considered a replacement for nighttime sleep. Napping actually offers a bunch of health benefits, including relaxation, reduced fatigue, increased alertness, as well as improved mood and performance, including quicker reaction time and better memory (7). However, it can’t be used as a substitute for regular sleep, as it doesn’t provide the same effects. Also, you should be careful with napping, as it might make you feel groggy and disoriented, as well as worsen nighttime sleep problems. The optimal nap is taken before mid-afternoon and short (10-20 minutes).
How To Improve Sleep Quality
Increase Bright Light Exposure During The Day
Daily sunlight and artificial bright light can improve both sleep quality and duration, particularly if you’ve got sleep issues or insomnia. In one study, two hours of bright light exposure throughout the day reduced waking time within sleep by two hours and improved sleep efficiency (2).
Reduce Blue Light Exposure In The Evening
Electronic devices like smartphones and computers emit blue light in large quantities, which disrupts circadian rhythm, tricking your brain into thinking it’s still daytime. This delays the brain’s release of melatonin, which lowers your chances of adequate sleep (9). Of course, it is better to avoid using your smartphone for at least half an hour before getting to sleep, but if it is too much for you, just turn on the blocker of blue light in the settings of your device.
No Caffeine Late In The Day
A rather obvious suggestion, but you should avoid consuming caffeine for 6 hours before sleep to ensure sleep quality and easy falling asleep.
Is 6 Hours Of Sleep Enough To Build Muscle: Final Thought
To conclude, poor sleep hinders your athletic performance and worsens your health condition in multiple ways. This oft-neglected factor turns out to be crucial in determining your muscle gains. An answer to the question «Is 6 hours of sleep enough to build muscle?» is a definite «No», and you should try as hard as possible to provide between 7 and 9 hours of sleep for your body, even if you have the busiest schedule in the world.
This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!
- Acute sleep loss results in tissue-specific alterations in genome-wide DNA methylation state and metabolic fuel utilization in humans (2018, advances.sciencemag.com)
- Bright light treatment improves sleep in institutionalised elderly-an open trial (2003, ncbi.nlm.nih.gov)
- Effect of 1 week of sleep restriction on testosterone levels in young healthy men (2011, ncbi.nlm.nih.gov)
- Growth hormone secretion during sleep (1968, ncbi.nlm.nih.gov)
- Insufficient sleep undermines dietary efforts to reduce adiposity (2010, ncbi.nlm.nih.gov)
- Intermittent-Sprint Performance and Muscle Glycogen after 30 h of Sleep Deprivation (2010, researchgate.net)
- Napping: Do’s and don’ts for healthy adults (2018, webmd.com)
- Physiology, Sleep Stages (2020, ncbi.nlm.nih.gov)
- The impact of light from computer monitors on melatonin levels in college students (2011, pubmed.ncbi.nlm.nih.gov)
- This Is How Many Hours of Sleep You Need to Build Muscle, According to an Expert (2019, popsugar.com)
- Why Do We Sleep, Anyway? (2007, healthysleep.med.harvard.edu)