SLEEP & EXERCISE

Recntly from the New York Times:

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. In fact, those cytokines also are released when people have a cold or infection, which is why people sleep so much when they are ill.
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, Dr. Chediak said. And, he noted, that’s what is happening when endurance athletes train. “A sprint will not get you as great an effect,” he said.