The role of sleep in athletic performance
Sleep is often the first thing players and coaches sacrifice, but that turns out to be a poor choice. In his 2011 article in Harvard Business Review, “Sleep is More Important than Food,” Tony Schwartz writes that even small amounts of sleep deprivation take a significant toll on our health. In fact, Amnesty International lists sleep deprivation as a form of torture.
People require sleep because of its restorative functions. According to Vancouver-based Fatigue Science, a fatigue-related risk management company, sleep plays a vital role in most of our physiological functions. Getting optimal sleep impacts such diverse bodily functions as motivation, focus, memory, judgement, muscle recovery, athletic performance, illness rates and body composition.
Athletes generally need seven-and-a-half to nine-and-a-half hours of sleep each night, and this number can vary depending on timing during the season and training load. However, Dr. Charles Samuels and Dr. Amy Bender of the Centre of Sleep & Human Performance in Calgary say that no amount of sleep can compensate if an athlete only gets poor quality sleep.
There are two main issues that can impact sleep quality: Non-restorative sleep, and disturbed sleep patterns. In non-restorative sleep, the athlete feels as though they’re getting sufficient sleep. However, they wake up unrefreshed, and during disturbed sleep, the athlete is restless or has fragmented sleep. A common type of disturbed sleep is insomnia, which is either the inability to fall asleep within 30 minutes of lying down or the inability to stay asleep.
Samuels and Bender say that feeling refreshed within 30 minutes of waking and not needing an alarm clock are both good signs that the athlete is getting proper quantity and quality of sleep. Sleep apnea also is a frequently undiagnosed cause of poor sleep, especially in athletes with larger neck circumferences or body builds.
Impact on performance
A recent study published in the Journal of Sleep Medicine looked at athletes in five university sports. It determined that sleep disorders among student-athletes may be related to late bedtime or use of cellphones after lights out; psychological distress; and competition activities, such as morning practices and stressors related to competition.
In a study of sleep extension in professional New Zealand rugby players, a small decrease in both stress hormone expression and reaction time was observed following the increase in players’ sleep times. Dr. Cheri Mah from the Stanford Sleep Disorders Clinic found similar results with collegiate men’s basketball players. When they increased their sleep times from six-and-a-half to eight-and-a-half hours, their free throw, 3-point shooting and sprint times all improved.
Napping during the day also has been shown to reduce sleepiness and enhance athletic performance in New Zealand netball athletes. A 20-minute nap on game day can improve jump velocity and improve subjective performance in elite netball players, as assessed by their coaching staffs.
Keys to quality sleep
1. Put down the devices. An article by Nicholas Bakalar in the New York Times discussed how bedtime reading with a tablet or smartphone can interfere with a good night’s sleep.
The experiment, described in Physiological Reports, found that when people used iPads instead of reading printed materials, they went to bed later and had lower levels of melatonin, the hormone that regulates sleep. Periods of REM sleep, the rapid eye movements of the dreaming stage of sleep, also were reduced when they used iPads. The volunteers reported feeling less sleepy in the evening and less alert in the morning after using the electronic devices.
2. Limit caffeine and alcohol. Caffeine can increase the time to fall asleep if taken too close to bedtime, while alcohol may cause fragmented and lighter sleep.
3. Be consistent with bedtime and wake time. Inconsistent bedtimes and wake times can cause havoc with an athlete’s sleep schedule. A consistent wake time is important. As is getting exposure to bright light in the morning to set the athlete’s biological rhythm to that time. Have athletes go to bed earlier and at a set time, using a reminder on their phones to keep on a regular sleep schedule.
4. Create an optimal sleep environment. According to a study by Dr. Yuichi Tamura and others, the room should be cool, dark and quiet. Use a comfortable pillow, mattress and bedding. Since light and sound can adversely affect sleep quality, use blackout curtains, an eye mask, a white noise machine or earplugs.
5. Develop a routine. Mah said in Sports Illustrated that a specific “wind-down routine” to prepare for sleep is key. She suggests athletes stop answering emails or doing other work and start winding down at least 45 minutes before bed. The athlete should create a ritual around something that helps them relax. That includes listening to music, stretching, reading, drinking a cup of herbal tea or meditating. Harvard Business Review’s Schwartz suggests that athletes write down what’s on their minds just before bed to transition thoughts out of working memory.
One final caveat: If an athlete does these things but still does not feel as though their sleep is restorative, or is dissatisfied with the quality of their sleep, they should seek help from a sleep professional.
Lisa Limper, MS, CSCS, AT has worked in professional, collegiate and high school athletics. She has been a personal trainer at the YMCA of Middle TN for 18 years. She also has served on committees for the NSCA and AFCA. Scott Lee, MS, CSCS, EMT/P has been a firefighter and paramedic for 20 years and a personal trainer for five. He has competed in powerlifting and strength competitions since 1990.