Aerobic exercise can improve the quality of sleep, according to Ken Diaz, a presenter with the Jacobs Fitness Center and department of recreation and fitness who gave a presentation Wednesday educating students about the benefits of exercise and sleep.
Diaz said there are two types of sleep. Slow wave sleep, which accounts for 75 percent of all sleep is the best type of sleep, he said. REM sleep, which stands for rapid eye movement, lasts for only five to 15 minutes at a time.
Slow wave sleep "hits you when you're tired," said Diaz, while REM affects "areas of the brain that are active although you are asleep."
According to the National Sleep Foundation, Americans get an average of 6.9 hours of sleep per night, compared to the recommended amount of 7.5 hours. If individuals do not sleep enough, they will suffer from a lack of concentration, decreased quality of work and more sugar in the blood, which can lead to pre-diabetic conditions, Diaz said.
Many individuals do not get the proper amount of sleep, and many more have trouble falling asleep, he said.
Diaz said slow wave sleep is the most desirable type of sleep and can be increased through regular aerobic exercise. Exercise lowers REM sleep or keeps it the same while at the same time increasing deep sleep, he said.
During deep sleep the body releases human growth hormone, which, he said, "helps muscles grow and encourages you to keep exercising." Diaz said because exercise causes one to feel good and sleep better, it "creates a cycle that hints there might be a connection between exercise and sleep."
Diaz also noted the connection between the type of sleep a person receives and clinical depression.
"People with depression spend too much time in REM sleep," he said, saying they may be helped by exercise since it reduces the amount of REM sleep.
Exercise also acts as a physical stressor, lowers the amount of time needed to fall asleep and increases the amount of deep sleep a person experiences, Diaz said.
For students looking to increase their quality of sleep, Diaz suggested doing at least 30 minutes of aerobic exercises, including walking, running, biking and swimming. He also suggested doing exercises that work legs, where some of the body's largest muscles are located.
Diaz also looked at other factors and their effect on sleep. Caffeine, he said, "will affect your quality of sleep," while alcohol "will inhibit sleep."
The best time of day to work out is in the afternoon or early evening, but Diaz added that it is an issue based on a person's schedule.
Some experts, according to Diaz, state that the best time of day to work out is five to six hours before going to bed because exercise raises body temperature, and subsequently the temperature of the brain, and as the brain cools off a person becomes drowsy.
Sleep has numerous benefits, including improving the immune system and cognitive abilities, consolidating memory and restoring the body, Diaz said.
"There isn't really one single function that sleep does," he said. "The point isn't to figure out what the sole function of sleep is ... it is part of the equation of good health"
