It’s football season, and with that comes renewed interest in the effects of sleep on athletic performance. I’ve seen a number of articles referencing the contribution that sleep makes to on-field performance, including a recent piece in the Wall Street Journal, which details the growing interest among college football coaching staff in leveraging sleep for their players’ and teams’ advantage.
Coaches at many top universities are digging into the science of sleep, and what it reveals about sleep’s power to boost athletic performance. Several college football programs are taking new steps to ensure their players are getting enough sleep. Some are using sleep tracking to monitor the quantity and quality of players’ sleep, others are hiring sleep coaches to help players establish and maintain healthy sleep routines throughout the season. One coach even took up residence in players’ dorm during training camp to ensure players were getting to bed on schedule.
Sleep’s a smart play
Devoting attention to sleep is a smart strategy and a wise investment for athletes and teams. Athletes face more widespread and greater threats to healthy sleep than ever before, coming not only from the rigors of their schedules, but also from sleep-stealing use of technology.
Technology used in the wrong ways at the wrong times can pose hazards to health and to sleep, for athletes and non-athletes. The nighttime use of smartphones, tablets, and other devices emit sleep-disrupting light that suppresses melatonin, throws off circadian rhythms, and delays the onset of sleep. The result? More daytime fatigue, and less robust performance on and off the field. Young people—including college, elite, and professional athletes—are more likely to be using technology, and more likely to have their sleep disrupted as a result.
Sleep powers performance
Scientific research has long pointed to the performance enhancing powers of sleep. In the world of athletics, every bit of performance—both mental and physical—is immensely valuable. From speed and reaction time to decision-making and recovery, both sleep quality and sleep quantity can make athletes stronger, quicker, smarter, and more agile. Take a look at some of the most important ways sleep influences athletic performance:
1. Energy. It’s a given that athletes must marshal tremendous energy to sustain themselves practices and competition. Lack of sufficient high-quality sleep limits and decreases energy in a number of ways. Poor sleep:
- Decreases glycogen storage. Glycogen is the body’s stored fuel. When the tank is low, athletes can’t function optimally, mentally or physically. In particular, the loss of deep sleep (stages 3 and 4) diminishes glycogen levels.
- Reduces testosterone. Testosterone enhances physical strength in both men and women. Testosterone strengthens muscles and bones, and promotes lean body mass. Testosterone levels diminish as a result of insufficient sleep, particularly REM sleep.
- Lowers HGH. This hormone in its natural state contributes to the restoration, repair and healthy growth of cells and tissues throughout the body. Sleep is an important time for the HGH-led restoration and renewal. This important hormone is released at higher levels during sleep, particularly during the early phases of deep, or slow-wave, sleep. Circadian rhythms influence HGH levels. Studies show that HGH decreases when circadian cycles are disrupted.
- Alters metabolism. Sleep helps to regulate metabolism, energy expenditure, and appetite. The balance of these factors is critical for athletes. Poor sleep upends that balance. When sleep deprived, appetite increases as toes the tendency to eat foods higher in sugar, fat, and carbohydrate. In a sleep-deprived state, the body adapts to increase energy consumption and decrease energy expenditure.
- Diminishes muscle memory. Sleep is critical to motor skill development and learning, as well as to muscle memory. Research has pinpointed a neurological process that occurs during sleep in which the brain processes and organizes motor learning. Some significant portion of this sleeping brain activity occurs in the supplementary motor area, a region of the brain that enables complex movement and coordination.
- Inflammation. Any athlete knows, inflammation equals pain, stiffness, reduced mobility and flexibility. Sleep plays an important role in managing inflammation. Sleep deprivation diminishes anti-inflammatory chemicals in the body, while at the same time increasing pro-inflammatory chemicals.
2. Reaction time. There’s a substantial body of research showing the effect sleep has on reaction time. Recent research suggests that reaction time may as much as triple as a consequence of sleep deprivation. Studies of college, elite, and professional athletes across a range of sports show sleep deprivation slows reaction time considerably.
3. Visual tracking. Research indicates that insufficient sleep impairs visual tracking skills. From hand-eye coordination to predicting trajectories, visual tracking skills are critical to gaining a competitive edge in sport.
4. Accuracy. Accuracy in physical, motor, and cognitive tasks is compromised by sleep deprivation, according to research. Diminished accuracy from insufficient sleep is on par with the effects of alcohol intoxication. That’s right—sleep deprivation is equivalent to drunkenness in its impairment of accuracy and other cognitive and motor functions. There’s also a direct correlation between hand-eye coordination and sleep.
5. Decision making. Assessing risks, making swift, complex decisions and on-the-spot judgment calls is part of the athlete’s challenge—and the ability to do so is key to athletic success. Numerous studies have demonstrated the negative effects of poor sleep on judgment and decision-making. Sleep deprived, we’re more likely to take unnecessary or ill-advised risks, despite being aware that those risks are present.
6. Memory. The brain is at work throughout all the stages of sleep to process, store, and secure memory. Sleep is a critical time for the brain to secure recently acquired information as memory, and to integrate that new learning with past experiences.
Athletes’ cognitive prowess is as important to their success as their physical excellence. Fascinating research shows how the brains of athletes are constantly making new neural connections, integrating information, relying on memory of previous experiences to make decisions and predictions swiftly and under pressure. Poor sleep undermines these important processes, impairing full memory function, and interfering with learning, storage and recall.
7. Recovery. Mental and physical recovery is essential athletes’ sustained performance—through the daily regimen of training, over a season of competition, and throughout the life of an athletic career. Sleep is essential to athletes’ recovery. Sleep deprivation and poor sleep quality both affect the restorative, recovery-based functions of sleep. So, too, does the disruption to circadian function that comes from irregular sleep habits, jet lag, and other sleep hazards that athletes commonly face.
Sleep also has a powerful influence over pain. Poor sleep slows healing. It also increases sensitivity to pain, lowering pain thresholds and elevating perceptions of pain. Sleeping well eases pain, and increases pain tolerance. Sleep also confers powerful rejuvenation and restoration of cognitive and physical skills and abilities.
The frontier of sleep as a tool and resource for athletes at all levels is an exciting one.
Michael J. Breus, PhD
The Sleep Doctor™