Good CrossFit athletes are often said to “eat and sleep” the program. Based on a great deal of athletic performance research, this may not be such a good thing. Among the overwhelming majority of high-performing athletes, quality sleep is an essential training component. Let's look at the connection between good sleep and fitness.
According to the National Sleep Foundation, “The quality and amount of sleep athletes get is often the key to winning. REM sleep in particular provides energy to both the brain and body. If sleep is cut short, the body doesn’t have time to repair memory, consolidate memory, and release hormones.”
High intensity exercise such as CrossFit depletes energy, fluids, and breaks down muscle. Hydration and the right fuel are only part of training and recovery. “What athletes do in the moments during and immediately after competition also determines how quickly their bodies rebuild muscle and replenish nutrients. This helps maintain endurance, speed and accuracy.”
The Stress Hormone: Cortisol
Many athletic trainers and physicians have noted that sleep deprivation can result in an increase in the “stress hormone” known as cortisol. An article in Psychology Today noted that “The stress hormone, cortisol is public health enemy number one. Scientists have known for years that elevated cortisol levels interfere with learning and memory, lower immune function and bone density, increase weight gain, blood pressure, cholesterol, heart disease. Chronic stress and elevated cortisol levels also increase risk for depression, mental illness, and lower life expectancy.
Cortisol is released in response to fear or stress by the adrenal glands as part of the “fight-or-flight” mechanism and adequate sleep helps to reduce its incidence in the body. Sleep deprivation has also been seen to decrease production of glycogen and carbohydrates that are stored for energy use during physical activity. In short, less sleep increases the possibility of fatigue, low energy, and poor focus at game time. It may also slow recovery after a workout.
Reduction of Injuries
Anyone who has gone through a grueling CrossFit session has first-hand knowledge of the potential for injuries in this setting. A University of California study concluded that injury rates in youth athletes increased during games that followed a night of sleep fewer than six hours. Another study looking at injury rates in high school athletes found that sleep hours was the strongest predictor of injuries, even more so than the hours of practice.
What accounts for this? First, fatigue affects reaction time and a tired athlete is slower to react to potential twists and turns of a CrossFit WOD. Secondly, fatigue affects the body’s immune system, making athletes more susceptible to illness. Finally, shorter sleep periods don’t provide the body with sufficient time to regenerate cells and repair from the abuse of workouts, games, and daily activities. As the research notes, “Over time, game-earned injuries, health issues, and the inability to fully recover can wear on an athlete and contribute to more time spent on the sidelines.”
Sleep Deprivation Can Drive You Crazy
Sleep deprivation can also have profound effects on one’s mental state. Dr. Joyce Walseben, a psychiatrist and the former director of Bellevue Hospital’s Sleep Disorders Center noted in an article in The Atlantic, “Sleep loss can cause psychological damage because sleep regulates the brain’s flow of epinephrine, dopamine, and serotonin, chemicals closely associated with mood and behavior.
“Mood and sleep use the same neurotransmitters,” she said. “It’s very hard to tell if someone has sleep loss or depression.” Walseban added, “When these neurotransmitters are disrupted by sleep loss, the chemical changes in the brain can also result in manic feelings and behavior similar to bi-polar disorder: high highs of ecstasy and low lows of depression and anger.”
Can You Make it up on the Weekend?
Everyone has heard about the athlete, student or business tycoon who regularly lives on fewer than five hours of sleep each night. While this is certainly possible to do, the long-range health dangers of this type of lifestyle are extremely real.
Some believe they can regularly pull all-nighters and then “make it up” on the weekend, or sometime later. This is also a fallacy. It is a similar problem found in jet-lag. “The problem, the researchers write, is that many people who chronically lose sleep live in societies where their work and school schedules are not aligned with the body’s circadian rhythms. So they never make up for lost sleep from the nights before, and build up a “sleep debt” that is never repaid. The consequence of chronic sleep debt is “social jetlag”—a chronic slowing of concentration and hampering of bodily systems.”
If you want to accelerate you CrossFit training impact, get some rest – anywhere from 8 to 9 hours each night. This will also speed your recovery time and give clear head when it comes time to go to the grocery store and buy some healthy food.Have you had any experience with the benefits of enough sleep and workout success? Post them below and we’ll share with our readers.