The Importance of Sleep on Performance and Recovery

Adequate sleep is necessary for healthy everyday functioning, but it is especially important when paired with exercise.  Sleep, along with proper fuel and hydration, are important for improving athletic performance, continual muscle growth, tissue repair, as well as reducing the risk of injury and weight gain.

How Much Sleep Do We Really Need?

Sleep is a key to success quite often highly underestimated and forgotten as critical in maintaining one’s health. Even though most of us know that a good night’s sleep is important, a small amount of individuals actually get 7 or more hours of sleep each night. For most, sleep-debt seems to become a common term during the busy work week and as one gets older.

So what is the recommended amount of sleep a person should be getting per night? Some of the many factors that determine this include: age, genetics, lifestyle, health, occupation, and stress. The real answer is that YOU determine this number. For college-aged students this could be somewhere between 6 to 10 hours, but as one gets older this number could shift towards 5-9 hours. Whether exercise has been part of your lifestyle for years or if it’s new to your routine, there are essential links to sleep, exercise, recovery and overall health.

How Sleep Affects Performance

Adequate sleep is necessary for healthy everyday functioning, but it is especially important when paired with exercise. Although some of the mechanisms of sleep still remain a mystery, research has shown that proper sleep improves mood, memory, concentration, performance, muscle repair, as well as many other crucial restorations of hormones. If one does not get an adequate amount of sleep, the body does not have enough time to complete all phases that are needed for optimal hormonal restoration and activity. REM sleep, which accounts for approx. 25% of the night, has been shown to provide energy both to the brain and body that allows us to stay alert throughout the day.

So how does a lack of sleep negatively affect ones performance? Sleep deprivation has been show to not only a reduce energy and motivation, but can impact ones performance both aerobically and anaerobically.  Bottom line is when one is exhausted and running on a little amount of sleep, working out could ultimately be counterproductive based on the fact that your hormones are still trying to recover and normalize from lack of sleep from the previous night. This could lead to an increased chance of illness and injury.

Increased Risk for Injury

When your body and mind are clouded by fatigue, several changes can occur if one chooses to exercise while in a state of sleep deprivation. Even though we may not notice this, or choose not to, it has been proven that an individual’s reaction time, thinking skills, judgement and attention are impaired. So is it worth risking an injury just to exercise? Perhaps it is better to rest and approach your next workout when you feel fresh and are operating more efficiently.

Exercise Recovery

No mater what exercise routine you perform; exercise depletes energy, fluids, and breaks down muscle. Hydration, proper fuel, and sleep are the three factors for aiding in proper rest and recovery. Research shows sleep to be an important factor in one’s health, weight and energy level. A typical night in a sleep cycle repeats itself about every 90 minutes. Non-rapid eye movement (NREM) begins immediately as we begin to fall asleep. NREM sleep is composed of stages 1-4 and takes up about 75% of a night’s sleep.

The most important stages for exercise recovery occur during NREM sleep stages 3 and 4. During this time hormones are released, such as: human growth hormone also known as HGH (essential for growth and muscle development). The body does most of its repair and regeneration work primarily during these stages due to a continual release of HGH. As a result, sleep is a key to improving athletic performance, continual muscle growth and tissue repair.

Less Sleep, More Weight?

Weight maintenance or loss is a popular short or long-term goal for people.  Research has shown that people who habitually sleep fewer than six hours per night are much more likely to gain weight than those who sleep an average of seven hours or more. We previously learned that sleep plays a major role in regulating hormones within our body. These hormones help control appetite, glucose processing and energy metabolism, therefore making sleep a regulator of weight. Poor sleep has been linked to increase levels of the stress hormone, cortisol. A disruption in cortisol has proven to be a large factor in weight gain and possibly an increase in blood pressure levels. Poor sleep also increases insulin secretion. After just one or two days without adequate levels of sleep, the body is no longer able to properly metabolize glucose. Higher levels of insulin are associated with weight gain and also increase the risk for diabetes. It is also important to know that poor sleep lowers the body’s levels of leptin (hormone that alerts the brain when it has had enough food) and increases levels of ghrelin (stimulates appetite). As a result, poor sleep may lead you to food cravings even after you have eaten adequate amount of calories. When you become fatigued, you may subconsciously gravitate towards unhealthy snacks that satisfy your cravings for a quick compensation of energy.

References

“Diet, Exercise and Sleep” National Sleep Foundation.Web.

Friedrich, Cathe. “Should You Exercise When You’re Tired or Sleep-Deprived?” Cathe. June 2013. Web.

Fullagar, Hugh HK, et al. “Sleep and Athletic Performance: The Effects of Sleep Loss on Exercise Performance, and Physiological and Cognitive Responses to Exercise.” Sports medicine 45.2 (2015): 161-186.

Grayson, Taylor. “A Recipe for Energy Management Success.” NCAA.com. 10 Sept. 2015. Web. <>.

“How Much Sleep Do We Really Need?” National Sleep Foundation. Web.

Ripton, Nancy. “The Shocking Truth About Sleep Deprivation.” Mens Fitness. Weider Publications. Web. <>.

Underwood, John. “Sleep and Recovery.” Life of an Athlete. Life of an Athlete Human Performance Lab. Web.

“What Happens When You Sleep” National Sleep Foundation. Web.