Can counting your ZZZ’s benefit athletic performance, or does exercise facilitate a better night’s sleep?
An inability to sleep and sleep well is a pervasive health concern in our society today. Although every scientific detail of how sleep regulates normal hormonal and metabolic processes is not yet completely understood, we must recognize the mounting evidence that physical exercise is an effective and drug-free way to manage both the quality and quantity of overnight rest.
Despite the medical community’s consensus that sufficient sleep and adequate exercise are pivotal in maintaining health, these behaviors within the typical American lifestyle are often not afforded the credence they so richly deserve. The Centers for Disease Control and Prevention estimate that nearly one-third of adults fail to attain the recommended seven hours of sleep per night, the amount experts have determined is needed for optimal health. The sleep deficit is even more of a concern in teenagers: roughly two-thirds of high-school students receive less than eight on school nights, when studies show that eight to ten hours would be more beneficial.
Alongside the lack of sleep, Americans have struggled to – or chosen not to — engage in the recommended amount of daily exercise. The 2015 National Health Interview Survey found that, from 1997 to 2015, over one-half of adults failed to meet the federal Physical Activity Guidelines for aerobic physical activity, and only one-fifth satisfied the federal Guidelines for both aerobic and muscle-strengthening activity. From 1988 to 2010, one study reported that the number of women who do not exercise recreationally jumped from 19.1% to 51.7%; their male counterparts’ participation also skyrocketed from 11.4% to 43.5%. Considering that the medical community has repeatedly demonstrated how exercise can function as a first line of defense against over 30 chronic health conditions, most notably cardiovascular disease and related disorders, this drastic reduction in leisure-time physical activity may contribute to the prevalence of lifestyle diseases currently seen, including sleep disturbances.
Which Came First?
Similar to the age-old “chicken or the egg” debate, exercise and sleep often seem to have this interactive dynamic. Which aspect of health might be optimized first: exercising to facilitate deeper sleep at night, or sleeping more to enhance sports performance?
The RAND research group recently presented an intensive in-depth analysis of how sleep affects us and what sleep deprivation can do to us—and to the economy. They estimate that between lost work and poor performance at work from lack of sleep, the U.S. alone loses $411 billion each year. Imagine the loss in sponsorship and endorsements a professional athlete might incur as a result of poor sleep patterns!
A new study presented at the Radiological Society of North America’s annual conference found that when individuals get an average of just three hours of sleep during a 24-hour period, their hearts suffer for it. The participants of this study revealed increases in contractility of their hearts, blood pressure, heart rate and levels of thyroid hormone and cortisol under such sleep-deprived conditions. Each of these factors can have a detrimental effect on physical performance in the gym, on the field, and in competitive events.
The Athlete’s Angle
Sleep deprivation or partial sleep loss are common in athletes competing in events such as ultra-marathons or triathlons that require them to cross several time zones. Although it is well established that sleep loss has negative effects on mental performance, its effects on physical performance are too prevalent to ignore.
Time to exhaustion becomes lessened by sleep deprivation, wreaking havoc with one’s endurance level, a key player in marathon-type races. Examination of the various hormonal /metabolic parameters that have been measured in multiple research studies reveals that the major metabolic disturbances accompanying sleep deprivation are an increase in insulin resistance and a decrease in glucose tolerance. This may explain the reduction in time to exhaustion observed in sleep-deprived subjects. If a client repeatedly finds himself unable to complete a set of repetitions, using a fairly comfortable weight load, it may be useful to inquire about his sleep habits.
Physical activity improves sleep quality and increases sleep duration. Engaging in active and purposeful movement throughout the day reduces stress and will typically cause fatigue by day’s end. As little as 10 minutes of aerobic exercise, such as walking or cycling, can dramatically improve the quality of nighttime sleep, especially when done on a regular basis. Taking this a step further, exercising regularly may reduce one’s risk for developing troublesome sleep disorders such as apnea and restless leg syndrome.
Daytime exercise may also help reset the sleep wake cycle by raising one’s body temperature slightly, then allowing it to drop, thereby triggering sleepiness a few hours later.
The Link Continues As We Age
Seventeen sedentary adults aged 55 years and older who were plagued by insomnia participated in a randomized controlled trial comparing 16 weeks of aerobic physical exercise to non-physical activity. Eligibility included suffering from primary insomnia for at least 3 months, with habitual sleep duration less than 6.5 hours per night. The subjects who engaged in physical activity improved their quality of sleep and sleep efficiency in comparison to the control group. The exercising group also had less evidence of depression and daytime sleepiness, and saw improvements in their overall daily vitality. It appears, then, as though aerobic physical activity may be an effective treatment approach to improve sleep quality, mood and quality of life in older adults with chronic insomnia. Educating the senior demographic of these facts is one way in which personal trainers can be of enormous help.
Just as athletes need more calories to fuel their bodies for their sport, they also require additional sleep: physical activity places increased demands on muscles and tissues, and the body takes advantage of sleep to repair itself. Sleep not only helps the body recover but can prove to be surefire performance booster. Exactly how much sleep one requires for optimal functioning is dependent on both genetics and how much physical activity is channeled into the sport (most adults need seven to nine hours a night, and athletes might improve their performance with up to 10 hours a night). Visual stage-of-sleep analysis of the sleep EEGs of 10 college athletes under three different conditions of exercise suggests a general positive relationship between exercise and the amount of slow-wave (delta) sleep in a night’s sleep.
If a client seems satisfied with the status quo of his workouts, it may come as a surprise when you reveal the multitude of positive results he might observe with just a few more hours of sleep each night. Here are a few of these benefits:
SPEED – Basketball players who can add an extra two hours of sleep a night boost their speed by five percent—and their accuracy by nine percent. Optimal slumber leads to faster reflexes reaction times.
INTENSITY – Athletes getting at least nine hours of sleep a night are more likely to do – and excel at — higher-intensity workouts such as weight lifting, biking, or running.
CEREBRAL STRENGTH – Training and competition can call for just as much mental strength as physical strength, and adequate sleep is a benefit here too. Well-rested athletes receive a boost in alertness and mood, which are both key for optimal performance.
COORDINATION – Sleep helps the body better consolidate memories linked to motor skills. In fact, adequate rest is vital for cementing recall linked to body movements. If an athlete’s goal is to be able to repeat that perfect tennis backhand from yesterday’s practice or hone his skills when shifting gears on a bike, sleep may be just as important as physical training sessions.
We can continue to debate where to begin this process of increased exercise/adequate sleep forever. Since benefits are observed on both sides of the fence, perhaps it is prudent to embark on this quest simultaneously. Work hard, play harder, and sweet dreams will come!