Apples for Health- Exercise does not improve sleep

Exercise does not improve sleep

SEATTLE, June 9 (UPI) -- U.S. researchers were surprised to find study participants sleeping less on days they exercised.

Lead study author Dr. Arn Eliasson of Walter Reed Army Medical Center in Washington says results of the study were the opposite of their expectations. Quality of sleep did not improve after days of increased exertion and sleep efficiency did not vary according to the amount of exertion during the day, the study said.

"It has long been recommended, even championed, that getting exercise is part of the recipe for improved sleep. Our data do not support that notion," Eliasson said in a statement.

"The longest sleep and best sleep efficiency occurred after days with low non-exercise exertion -- better rested subjects got less exercise and had less calorie expenditure. After relatively more sleep -- more than six hours -- all measures of exertion decreased."

The study included 14 subjects who wore actigraphy armbands for 23 days. Data regarding total sleep time, sleep efficiency, total energy expenditure, exercise energy expenditure, non-exercise activity steps and body mass were collected.

Seven subjects had a normal body mass and seven were overweight. Paradoxically, the researchers say, the group considered overweight had a higher total energy expenditure, and took more steps per day.

The study was presented at Sleep, the annual meeting of the Association of Sleep Professionals in Seattle.