Exercise is an important component of a healthy lifestyle. Combined with other positive lifestyle habits such as a healthy diet and stress reduction, exercise can help prevent obesity, metabolic syndrome, cardiovascular diseases, type 2 diabetes and other serious health conditions. It can also help people who already have some of these conditions to lessen or reverse their symptoms. Exercise can only help us if we do it regularly; and if we don’t recover well, sore muscles might kill our motivation and stop our progress. But why is sleep important for muscle recovery? Well, our bodies repair themselves at night while we’re sleeping, which is why a good nights’ sleep is critical for muscle recovery.
How does your body repair itself during sleep?
Several hormonal changes occur in your body as you prepare for bed and as you sleep — and these changes play a big role in how well your body recovers after exercise:
- Human growth hormone (HGH), which is necessary for body restoration and plays an important role in muscle growth and repair, is mostly secreted from the pituitary gland while you sleep. Specifically, HGH is secreted during deep (i.e., slow wave) sleep, also known as stage 3 of non-REM sleep. That’s why quality, and not just quantity, of sleep matters.
- Cortisol plays an important role in the physiological and behavioral responses to physical activity, in maintaining metabolic function and in regulating the immune system. Testosterone helps build muscle. Both hormones follow a circadian rhythm and are impacted by sleep deprivation. Disrupting the balance of these hormones can have serious downstream consequences, including reduced recovery, reduced immune system function and altered metabolism.
While most studies investigating the relationship between HGH, cortisol and testosterone have been performed on elite athletes, the underlying physiology is the same — and anyone participating in physical activity can benefit from a good night’s sleep. Even if you aren’t interested in maintaining the correct testosterone levels to build muscle mass, there are other beneficial impacts of a good night’s sleep that affect how you feel on a daily basis — which could play a role in whether you feel like exercising or not.
Other ways poor sleep can compromise your health
Aside from impacting the balance of hormones that play a direct role in muscle and tissue building and recovery, poor sleep can negatively impact your physiology in ways that can further reduce muscle recovery and/or contribute to risks of other systemic comorbidities. For example:
- A poor night’s sleep can lead to dysregulated inflammatory processes and other immune system impacts, which can have several downstream effects:
- Prevention of adequate recovery after exercise
- Weakened adaptive immunity (i.e., immune response to infections), including a reduced ability to “remember” previous infections and react appropriately to new ones
- Decreased effectiveness of vaccines
- Higher susceptibility to allergic reactions
- Increased risk for diabetes, heart problems, and infection
- Hampered healing after injury/illness
- Population-based longitudinal research studies have shown that sleep impairment can predict new incidents of and exacerbations of chronic pain.
- Sleep also contributes to cognitive repair, and long-term sleep deprivation can lead to cognitive decline as well as a higher risk for depression
- Poor sleep not only prevents adequate muscle recovery, it can also increase your risk for weight gain and other cardiometabolic conditions. When you’re sore, in pain, or feeling less than sharp mentally, your motivation to exercise (and pretty much anything else) drops. This in turn can then stall efforts to lose weight and increase your risk for metabolic issues and cardiovascular diseases, especially if you’re already at risk.
- Just like sleep impacts hormones involved in muscle building and repair, it also affects hormones that play a role in appetite. Too little sleep tips the balance toward the appetite-stimulating hormone ghrelin, making you want to eat more when you’re sleep-deprived.
- Too little sleep also decreases insulin sensitivity, increasing your risk for type 2 diabetes or making it more difficult for diabetic individuals to control their blood sugar levels. Insulin resistance also alters your body’s ability to restore glycogen, the fuel for muscles, so you won’t be able to work out as long and will be unable to reap the full benefits of your exercise program.
6 tips for better sleep
So, how can you get more shuteye given we know sleep is important for muscle recovery? Below are six simple lifestyle hacks you can employ today to be on your way to better sleep:
- Exercise! That’s right, not only can a good night’s sleep improve your exercise regimen, but exercise can help improve your sleep. Just be sure to finish your last workout at least two hours before going to bed.
- Set and follow a schedule. Going to bed and waking up at the same time each day can ensure you get enough sleep each night. Aim for 7-9 hours each night.
- Create your sleep environment. Keep your bedroom dark and cool (experts say around 65 degrees is the optimal temperature for sleep) and use your bed only for sleeping. If you want to read before bed to wind down, find a comfortable chair, read until you’re sleepy and then go to bed.
- Limit screen time. Blue light emitted by screens (phones, TVs, computers) can disrupt your sleep cycle and lead to lower quality sleep by preventing your body from producing melatonin, the hormone that tells your body it’s time to sleep. Try wearing blue light blocking glasses for at least two hours before bed to ensure your body produces melatonin.
- Meditate. Studies have shown that meditation/mindfulness exercises can improve your sleep by decreasing symptoms of insomnia and fatigue. Such practices also reduce stress, which can impact sleep quality as well.
- Make careful food selections. Certain foods can either promote or prevent a good night’s sleep. According to the National Sleep Foundation, foods that combine complex carbs and protein, such as whole-grain toast with peanut butter, can help you fall asleep by delivering the amino acid tryptophan to your brain. Be sure to finish eating any meals and snacks at least two hours before heading to bed, though.
If you’re still having trouble sleeping at night, talk to your doctor about ways you can improve your sleep or to determine whether low energy might be due to another, underlying problem unrelated to sleep.
Are naps good for muscle recovery?
For years, the idea that naps could help you “catch up on” lost sleep has been touted as a myth. However, more and more research suggests that naps could actually be beneficial after all. A recent review assessing 19 research studies revealed that daytime naps have several positive impacts for physically active people:
- Improved short-term physical performance
- Improved endurance
- Improved reaction time
- Improved attention
- Improved short-term memory
The review also found that positive impacts on physical and cognitive performance were associated with “replacement” naps only; in other words, napping to replace lost sleep is a good strategy, but napping when you’ve already gotten enough sleep doesn’t really seem to help.
Another review assessing over 30 studies reported similar results, and additionally suggested that optimal nap durations were between 20 and 90 minutes. However, both reviews emphasize that many of the studies didn’t follow a high-quality study design and could be prone to confounding variables or missing data. So for now, while it seems that naps do have a positive impact on physical and cognitive function, the jury is still out on what might be the optimum nap duration and what time of day is the best time to nap.
Getting a good night’s sleep is vitally important to your health on a number of levels. If you’re engaged in an exercise program to lose weight and/or improve your metabolic health, sleep could play a big role in the success of your program. Not only does a good night’s sleep directly impact how well your muscles recover (and therefore, how motivated you are to keep going), it can also impact your immune system and metabolic health as well. There are simple strategies you can take right now to improve your sleep quality, such as sticking to a schedule, engaging in relaxation techniques and eating the right foods. You can also talk with your doctor about sleep hygiene and specific ways to improve your sleep quality today.