I was taught that regular exercise can improve sleep quality. My patients have told me that sometimes they sleep better if they are "worn out" from exercise or just physical exertion. Exercising upon awakening can help regulate your body clock, giving it a routine. This study in the Journal of Clinical Sleep Medicine studied 11 women with an average age of 61 years. They had the women wear actigraphs, which measure sleep at home. The women also did moderate aerobic exercise 3-4 times per week. The results showed that exercise duration did not correlate with sleep improvements. But sleep duration did correlate with exercise duration - the shorter the total sleep time, the shorter the exercise duration the next day. This makes sense to me. From my own experience, if I get little sleep while on call, I am less likely to exercise the next morning.