The Globe and Mail examines the positive impact of exercise on sleep.

“We can pretty confidently say exercise improves sleep,” Dr. Kline says, “but in terms of translating that to a public-health message to recommend something – we can’t really make any substantive recommendations based on the research.”

Dr. Kline is one of a growing number of scientists doing work to change that. His recent work includes a randomized, controlled study of 43 overweight and obese adults with untreated obstructive sleep apnea – a disorder that causes pauses in breathing during sleep. The study found that, with exercise training, sleep apnea symptoms can be reduced. He has also done a meta-analysis in the journal Lung of five exercise-and-sleep-apnea studies that found similar results, including an indication that exercise can reduce symptoms of the disorder even if it doesn’t result in weight loss.