Sleep is the ultimate performance enhancer. When considering factors of optimal performance, we often list off nutrition tips, training schedules and recovery regimens. Sleep usually doesn’t get a mention here, but it should. If we don’t sleep, our nutrition and countless hours of training will go to waste. Our bodies need sleep for performance and for recovery. Without sleep, our bodies break down and our athletic performance suffers. When life gets busy, it is too easy to compromise our sleep schedules. However, the additional hours of consciousness aren’t doing us any favors. While we may get used to sleeping 5-6 hours every night, our bodies don’t like it and we will eventually pay for it. In order to operate at your highest level, you need to prioritize sleep.
Why Do We Actually Need Sleep?
How much sleep did you get last night? Depending on your answer you either feel refreshed today or completely wrecked. We all know that sleep is a powerful determinant of human function. Personal experience has taught most of us that sleep is a non-negotiable component of well-being, yet scientists have yet to figure out exactly why we need sleep. What science has shown us though, is that a lack of sleep is detrimental to our health.
Beyond the obvious side effect of fatigue, a sleep deficit negatively influences almost every one of the body’s physiological processes. When we don’t sleep our bodies break down and we cannot recover well. We are more likely to get sick, our metabolism slows, our concentration wanes and our physical performance suffers. A failure to prioritize sleep will leave us unable to reap the benefits of our otherwise healthy and active lifestyles.
The Sleep Cycle
A sleep cycle is comprised of five stages of sleep. The first four stages of sleep are known as non-rapid eye movement (NREM) sleep and the fifth stage is known as rapid eye movement (REM) sleep. During the four stages of NREM sleep, we progress from light sleep to deep sleep. The fifth stage, REM sleep, is the most active stage of sleep. Our muscles are relaxed, but our brainwaves are highly active and we experience rapid eye movements. Dreaming and memory consolidation occur during REM sleep.
We spend about 50% of sleeping time in stage two of sleep, 20% in REM sleep and the remaining time in the other stages. Each sleep cycle lasts about 90 minutes. If we get a full night’s sleep, we experience 4-6 sleep cycles per night.
In order to adequately recover from exercise, we must experience all five stages of sleep. We must also sleep 7-8 hours for our bodies to undergo all of the restorative physiologic processes of sleep. During the first 2-3 sleep cycles, we spend more time in NREM sleep and during the final 2-3 sleep cycles, we spend more time in REM sleep. This means that most of us will experience more NREM sleep earlier in the night and more REM sleep in the early morning hours. So those of us who tend to burn the candle at both ends, going to bed late and waking up early, will miss out on REM sleep and perhaps even the deepest stages of sleep, stages three and four.
Sleep is a Performance Enhancer
By allowing the brain and body to rest and restore, we leave ourselves better prepared for an intense training session. Athletes who sleep more demonstrate improved reaction times, higher speed, less fatigue and better moods. It is also easier to learn a new skill when we are well rested.
The bottom line? There is no substitution for sleep. If we don’t get enough of it, we will not be able to perform the way we want to. Endurance training, weight lifting performance, and motivation to exercise are all negatively influenced by a lack of sleep.
Countless sleep deprivation studies have demonstrated the effects of sleep on athletic performance. Cyclists deprived of sleep demonstrate negative mood changes and worsening reaction times. Weight lifters who were restricted to three hours of sleep for three consecutive nights demonstrated decreased performance on submaximal lifts for a biceps curl, a bench press, a leg press and a deadlift compared to their counterparts who slept a full night. These same weight lifters also experienced less vigor when exercising. Endurance athletes who are sleep deprived have been shown to run shorter distances at a greater perceived effort than their sleep-rich counterparts, who ran longer distances at the same perception of effort. Essentially, when we sleep less we are more likely to quit earlier because exercise feels harder.
Sleep readies our brain for physical activity too. When we train, we are often learning new movements. Additionally, athletic competition requires us to perform cognitive tasks while also expending physical energy. Lack of sleep makes it more difficult to learn movements and perform complex physical skills.
Sleep deprivation can also leave athletes more susceptible to overtraining syndrome. A reduction in sleep results in imbalances in the neuroendocrine system, stimulating overtraining syndrome. When training under a sleep debt, our bodies are more likely to perceive training as overtraining. Our immune system is also impaired when we do not get enough sleep. We are therefore not prepared to take on increased physical demands and are more likely to break down and get sick.
Sleep is a Recovery Aid
In addition to improving our performance, sleep also helps us recover from exercise. When we don’t get enough sleep after training, our bodies cannot properly recover. Therefore, entering a sleep debt while training creates a vicious cycle. We wake up without having recovered from the previous day’s session and we start today’s session without our most important performance enhancer.
Several studies have demonstrated sleep’s powerful influence on recovery by examining athletes after exercise and subsequent sleep deprivation. Cyclists who slept for 3-4 hours after a HIIT session demonstrated a reduction in peak power output the next day, while also reporting more fatigue and less motivation to train. Rugby players who were sleep deprived after a competitive match demonstrated declines in counter movement jump distances and slower reaction times the next morning.
The major lesson here is that sleep is critical after training and competition. If for some reason an athlete is unable to get adequate sleep after exercise, then training demands should be adjusted the following day.
Sleep deprivation also robs us of important physiologic recovery benefits of exercise. When we participate in high intensity training, we experience a 24 hour reduction in systolic blood pressure. However, athletes who are deprived of sleep fail to demonstrate this beneficial change in blood pressure. Individuals who are deprived of sleep after exercise also exhibit higher blood glucose levels than athletes who slept a full night. This effect will negatively influence our metabolism, energy levels, and eating habits.
Maximizing Sleep Potential with Protein
When we sleep, we undergo protein synthesis. The body’s cells demonstrate increased production and decreased breakdown of protein during sleep, setting us up for improvements in strength and endurance. We can capitalize on this benefit by ingesting protein before sleep. A small protein-rich snack allows us to take advantage of the muscle repair processes that happen overnight.
Remember the movie Million Dollar Baby? Hilary Swank put on 23 pounds of muscle for her role as boxer. She would wake up every few hours during the night to drink protein shakes in order to keep her muscle protein synthesis rates elevated. For almost all of us this approach is much too extreme, but there is something to be learned from Swank’s dietary schedule. When we sleep, our body is relying on the last bit of nutrients we had before bed. Furthermore, our muscles’ ability to use protein is limited by the availability of circulating amino acids and protein. If we take in protein before bed, we can better stimulate overnight protein synthesis rates and enhance the body’s protein stores.
Studies have demonstrated that athletes who drink [casein] protein before bed effectively digest and absorb the protein overnight, resulting in increased circulating amino acid levels and higher protein synthesis rates. The hope here is that this will result in improved gains in muscle mass and strength.
While these studies have effectively linked protein ingestion before bed to improved protein synthesis rates, they have yet to determine the amount of protein needed for these positive effects. Studies have demonstrated benefits using anywhere from 28g to 40g of protein. It has yet to be determined if a smaller amount will show the same effect. We also still need to see studies that demonstrate which type of protein best stimulates overnight protein synthesis.
If eating before bed doesn’t sit well with you, then make sure have some protein with your breakfast. Since we’ve been depriving our bodies of this important nutrient all night, it is important to give our muscles a chance to start rebuilding and provide the body with the tools it needs to recharge.
Sleep Well Tonight
Sleep is a power player in our performance as athletes. It enhances the quality of our training, ensures proper recovery and motivates us to push a little harder. Don’t skip out on this critical element to physical function. Starting making sleep a priority and your body will thank you.
While there are many elements that contribute to sleep, there are several actions we can take to ensure that we experience fully restorative sleep. Here are some helpful tips to make sure you get a good night’s sleep tonight:
●Sleep for 7-9 hours. Even though you may feel used to less sleep, your body will not truly be able to adapt to a sleep deficit.
●Go to bed and wake up at the same time every day (yes, this includes weekends). Maintaining a consistent sleep schedule allows us to go to bed and wake up with more ease. An erratic sleep schedule results in impaired performance and function throughout the day.
●Try not to exercise within 4 hours of bedtime. Daily exercise is great for our overall sleep quality, but exercising too close to bedtime makes it difficult to fall asleep because we will experience an increase in body temperature. This four hour window lets our body temperature fall naturally by the time we go to sleep.
●Avoid caffeine after 2pm. Caffeine is a stimulant and it is metabolized slowly. We need to provide enough time to reduce its effects before sleep.
●Avoid nicotine. Nicotine reduces REM sleep because it wakes you up every 3-4 hours due to nicotine withdrawal.
●Avoid alcohol within 3 hours of bedtime. This time frame gives us enough time to metabolize alcohol. Drinking too close to bedtime may let you fall asleep faster, but it prevents us from entering the restorative stages of sleep (stages three, four and REM).
●Keep your bedroom between 60-75 degrees Fahrenheit. Extreme temperatures interfere with sleep quality.
●No screen time 2-3 hours before bed. The blue light from our phones and computers suppresses the production of melatonin, a hormone that regulates sleep and wakefulness. While any light can suppress melatonin, blue light is the most significant in disrupting sleep quality. (Fun fact: caffeine and alcohol also inhibit the production of melatonin).
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