Sleep and Exercise – Kimberly Baldyga

When it comes to the topic of exercise and sleep, which comes first: the pillow or the sneakers?  Many times a common factor in preventing someone from exercising is that they are too tired, but exercise may actually help you sleep better, aid in recovery and ultimately sleeping better will lead you to an even greater workout and results in training.

Sleep is one of the most important necessities in life and is not only based on how much you get, but by the quality of the hours you spend under the covers.  Your body uses this time to repair muscles and undergo protein synthesis, release proper hormones and can prevent cardiovascular and metabolic diseases. 

Muscle repair and recovery

       Resting and allowing your muscles to recover is equally as important as the work you put into your training.  Heavy training will damage the muscle tissue in order to improve your fitness and rebuild that muscle to become stronger.  Growth hormone stimulates growth of the muscles and cell reproduction and regeneration. 

The pituitary gland releases growth hormone in a pulsatile manner.  At rest, these concentrations are not very high, but when an individual goes to sleep, the levels released increase.  This usually occurs when the body is in non-REM sleep, or about two hours after going to sleep.

  Consistent bed times are extremely important because your body will begin to release its peak at that same time of night, almost like a rhythm.  Your body will secrete growth hormone at other times of the day in smaller amounts but the highest point will be in that onset of sleep.

If the individual continues to go to sleep at different times each night, or does not have a good quality sleep, the release of growth hormone will be reduced.  The body will not realize the individual is in that stage of sleep where the greatest amount should be released, so the body will continue to release the smaller pulses. 

This leads to less repair and growth of the muscles.  The right amount of sleep will depend on each person, but quality of sleep will allow the individual to fully go into all of the stages of sleep and release the largest volume of growth hormone to benefit them.

Sleep and body weight

       Growth hormone is not the only hormone that is regulated while you sleep.  Leptin and ghrelin are two hormones associated with hunger and appetite.  Leptin works to suppress hunger, and ghrelin stimulates appetite.  When you are exercising and training for hours a day and stressing the body, it is hard enough to maintain proper nutrition and food intake. 

When you skip on sleep, or demonstrate poor sleep quality, these levels of hormones try to compensate for the energy expenditure leading to increased levels of ghrelin and decreased levels of leptin. 

Someone who is exercising to lose weight but not seeing results may be experiencing these changes in hormones, putting a detrimental effect on their performance and training. This can also lead to eating more empty calories and carbohydrates then the body needs.

Exercise effects sleep, sleep effects exercise

       Counting sheep, a dark room, warm milk and exercise?  Increasing your physical activity in your daily routine has been shown in studies to increase the amount of time in non-rapid eye movement sleep. 

       Exercise helps to alter the body’s circadian rhythm which tells us when to sleep and when to be functional.  This can benefit someone who is having trouble falling asleep or staying asleep because the body may need to be adjusted to different hours of sleep or work you are undergoing.

       Different intensities of exercise have different effects on everyone, promoting better sleep in some people right after an intense workout, or giving some people an effect similar to caffeine to re-energize the body. 

Exercising outdoors in the natural light can also benefit the mind and mood of the individual, allowing less anxiety and stress and a more peaceful sleep.

       When the core temperature of the body comes down, it is easier for the onset of sleep to occur.  Your temperature changes throughout the day and is highest first thing in the morning. 

Exercise will raise your core body temperature, allowing it to peak again, giving you more energy.  This will also enable the temperature to drop easier and deeper leading to a better sleep.

       Adding exercise into your daily routine promotes healthier sleeping habits, but on the other side of things, a lack of sleep can hinder performance and training. If you are tired and lack energy to complete a vigorous workout, you may be more prone to injury and improper form.  Your reaction time will be slower and performing at your optimal level will be harder to achieve. 

The body will need even more time to repair and recover when tired but if you skip on sleep again, it will not be able to release the proper amount of growth hormone which will leave the muscles damaged.  If someone gets stuck in this type of cycle, it can lead to overtraining and injury.

       Both exercise and sleep effect each other tremendously.  The body needs enough sleep in order to function properly and have enough energy to train hard.  However, all of the hard work will not pay off unless you rest and repair the muscles through sleep. 

The optimal amount of sleep is dependent upon the individual person, but ensuring the same general onset of sleep and quality of sleep each night will produce the most favorable hormonal releases, muscle repair, recovery and performance.  You snooze, you succeed.