Sleep and Exercise

If someone told you that time spent in the gym is just as important as the time spent asleep, would you believe them? The truth is, sleep and exercise are both essential to the body’s overall health. While we may think of physical activity as the best thing you can do to keep your body healthy, the reality is that your time resting and giving the body time to reset is equally as important.

Sleep may help you feel ready to exercise, while regular exercise may support better sleep. Understanding the relationship between sleep and exercise can help you make healthier choices that improve both your sleep and your fitness level.

Based on the evidence around optimum sleep duration for supporting healthy outcomes, the National Sleep Foundation recommends that adults sleep between 7 and 9 hours each night.¹ In addition to the duration of sleep you get each night, other features of sleep also affect its quality. For instance, being able to fall asleep quickly and to stay asleep are important aspects of healthy sleep. Sleep efficiency, a measure of how much time you spend asleep while in bed, is also an indicator of the quality of your sleep.

When people fail to get enough good quality sleep – even in the short-term – their overall health and wellness may be impacted.²

The quality of our sleep can have a major impact on our mental health and mood.² Without proper sleep, we are more likely to be irritable and react poorly to stress.

Over time, sleep deprivation can make it difficult for the brain to process stressful situations or events, impacting mental health.²

The quality of our sleep has serious implications for our cognition and attention.³ Sleep deprivation makes us less vigilant and less alert. Because sleep is required for memory consolidation, inadequate sleep can also lead to deficits in both short-term and long-term memory.³

While we sleep, the brain clears out byproducts of metabolism accumulated throughout the day.⁴ REM sleep also gives the brain time to remodel the parts of our brain cells that communicate with one another.⁵ This communication is critical for our understanding of our world.

Long-term sleep deprivation leads to poorer overall health.^6,7 Research shows that a lack of sleep can make a significant impact on some of our most important organs like the brain, heart, immune system, and digestive tract.⁶

Sleep disturbance has been shown to be associated with lower physical fitness which is important for day-to-day activities and enjoying a high quality of life. That’s why it is so critical to do what we can to stay active. Improving sleep hygiene is one way to equip our bodies with what they need to stay active and keep moving.

If your body is exhausted, you’re not going to want to exercise or move too far from the couch—plain and simple. In reality, fatigue can hinder our ability to exercise after just one night of bad sleep or more following regular sleep disturbances.

Sleep has been shown to affect hormone functioning, some of which may affect fitness.^{8, 9} For instance, sleep restriction has been shown to increase levels of ghrelin, a hormone that triggers hunger, as well as to decrease levels of leptin, a hormone that helps us feel full following a meal. We are therefore more likely to overeat when we are sleep deprived than when we have had adequate sleep. And if your body is focused on food, or busy digesting a huge meal, you won’t want to do a set of squats or jumping jacks.

Over time, a lack of sleep may increase your blood sugar levels. This is your body’s way of fueling your daily mental and physical functions.¹⁰ Unfortunately, a consistent lack of sleep can make it difficult to maintain healthy blood sugar levels, leading to a number of changes in our metabolism that ultimately result in increased food intake. These types of changes are often accompanied by reduced physical fitness. ¹¹

Research has shown that sleep can play a significant role not just in overall physical fitness but specifically in muscle strength. Studies suggest that those who experience adequate sleep and report good sleep quality are more likely to have greater muscle strength. Those who sleep fewer hours are more likely to have lower muscle strength and lower muscle mass.11

Skeletal muscle protein synthesis, or the process that maintains and strengthens muscles, occurs throughout the day after you eat, exercise, and more. A review of studies of short-term sleep deprivation, suggests that associated metabolic changes due to lower testosterone and higher cortisol levels may hamper the pathways involved in muscle protein synthesis. ¹¹

The review also found that short-term sleep loss may also trigger an increase in appetite and metabolic changes leading to an increase in fat deposition, especially around the belly. ¹¹

Getting up and moving is key to keeping yourself physically fit. While any type of exercise may improve sleep - especially on a regular basis - research highlights specific benefits of some common types of exercises.

Aerobic exercise and resistance training programs have been shown to lead to improved self-rated sleep quality and faster time to fall asleep.^12,13 Aerobic exercise, or cardio, encourages the body to use up more oxygen and pump blood throughout the body. It can include walking, biking, and more. Resistance training encourages you to improve muscle strength and endurance, often including weights.

Yoga has been shown to improve sleep and cognitive functioning.¹⁴ Those who initiate a yoga program may increase their chances of falling asleep more quickly and sleeping for longer durations.¹⁵ Yoga is thought to achieve its sleep benefits through its impact on autonomic functioning and metabolism, and by improving the connectivity of parts of the brain.¹⁴ > The key is –exercising is essential to supporting your overall health, and can encourage a good night’s sleep, so choose exercise times and intensity that work best for you.

Sleep, physical fitness, and overall health and well-being are intimately intertwined. While it is critical to our health to have both good sleep habits and good exercise habits, it can be difficult to maintain physical fitness when we are sleep deprived. By prioritizing exercise and healthy sleeping habits, we can help fuel our bodies so that they can function at their optimal level, which can enable us to feel fitter, healthier, and happier.

Establishing healthy sleep habits is essential to your overall health. Promoting a healthy lifestyle goes hand-in-hand with ensuring you are not only getting enough sleep, but also getting quality sleep.

ZzzQuil is here to help you on your journey to your best sleep. Sign up for ZzzQuil’s Better Sleep in 1-2-Zzz for ZzzQuil’s Best Sleep in 1-2-Zzz to learn more about how you can optimize your sleep routine.