Who Needs a Nap?
Moderate exercise can help us to sleep better at night.
So a harder workout would help us sleep even more soundly, right?
Uh, not exactly.
If you find yourself tossing and turning after vigorous training sessions, you may want to check out Gina Kolata’s NYT article “Sleep After Hard Workouts? You Must be Dreaming.” An excerpt:
It’s one of the mysteries of sleep: Why is it that mild exercise can be invigorating, but strenuous endurance exercise — whether it’s crew practice, long runs as training for a marathon or juggling back-to-back workouts to prepare for a triathlon — makes people groggy?
Sleep specialists often tell people with insomnia to exercise five to six hours before bedtime. The mild exercise raises the body’s core temperature. When the temperature falls again a few hours later, that signals the body to sleep.
But that is a different sort of exercise from what endurance athletes do, and so what happens to marathoners-in-training must have another explanation. One possibility is that cytokines — hormones that signal the immune system — are making these athletes sleep so much.
Exercise, Dr. Chediak said, prompts muscles to release two cytokines, interleukin 6 and tumor necrosis factor alpha, that make people drowsy and prolong the time they remain sleeping.
It turns out that the single most important factor for increasing the release of those two cytokines is increasing the duration and intensity of exercise, [which is] what happens when endurance athletes train.
The article goes on to explore “whether a sleepless night before the race affects athletic performance.” Give it a read, go fun a run, then take a nap.