Exercise may not be too stimulating before sleep -- it may even be helpful, according to a recent survey conducted for the National Sleep Foundation.
In a poll of 1,000 adults aged 23 to 60, those categorized as "vigorous exercisers" were almost twice as likely as non-exercisers to say they had a good night's sleep "almost every night."
"There seemed to be a dose-response effect," said Christopher Kline, a sleep researcher at the University of Pittsburgh School of Medicine, one of five experts chosen by the National Sleep Foundation to advise on poll questions and interpret results. "The more you exercise, the better you'll sleep."
But "the biggest bang for your buck was from no-exercisers to light-exercisers," Dr. Kline said. "You get the most benefit from exercise when you move from no exercise to just a little exercise."
Whatever your exercise habits, you're more likely to have trouble sleeping if you sit too long during the day, the survey indicated. Respondents who sat for less than eight hours a day were twice as likely to say they had "very good" sleep quality than did those who sat for eight hours or more.
"If you spend the rest of the day sitting down, a lot of the health effects of exercise are negated," Dr. Kline said.
No research before had connected sedentary behavior with poor sleep, he said.
No difference in the quality of their sleep was reported by those who exercised at night and those who exercised earlier in the day.
"This was the finding that was somewhat surprising to me," said Daniel Shade, a sleep specialist with Allegheny General Hospital. "We would say you shouldn't exercise closer to bedtime than four to six hours. The thinking was you would be hyperactivated, hyperaroused."
As a result of this finding, he'll probably alter the advice he gives patients, Dr. Shade said.
"You might tell insomniacs they should exercise earlier in the day," he said. "But if you are normal, apparently it doesn't matter when you work out."
What's important is that the more you exercise, the better you'll sleep, "so we can tell our patients to keep moving," Dr. Shade said.
Exercising late doesn't interfere with their sleep, said people who were working out at Club Julian in Ross after 9 p.m. on a recent night.
Dana Sabo, 43, teaches fitness classes three nights a week after her day job handling billing for a law firm.
"I definitely sleep better" on the nights she teaches, Ms. Sabo said. "I take a shower and go right to bed."
"If I don't work out, I have a hard time falling asleep," said Kayci Lebak, 22, a patient advocate at UPMC Passavant hospital.
In the poll, which was conducted by WB&A Market Research for the National Sleep Foundation, 18 percent of respondents described themselves as "vigorous" exercisers, 25 percent as "moderate" exercisers, and 48 percent as "light" exercisers. Nine percent said they didn't exercise at all.
Eighty-three percent of vigorous exercisers, 77 percent of moderate exercisers, and 76 percent of light exercisers -- but only 56 percent of non-exercisers -- described the quality of their sleep as "fairly good" or better.
The quality of their sleep improves on days they exercise, said 62 percent of vigorous exercisers, 54 percent of moderate exercisers, and 49 percent of light exercisers.
Eight percent of vigorous exercisers, 14 percent of moderate exercisers, 16 percent of light exercisers and 24 percent of non-exercisers said they had difficulty falling asleep. It took vigorous exercisers just 16.6 minutes, on average, to fall asleep, compared to 20.5 minutes for moderate exercisers, 22.6 minutes for light exercisers, and 26.3 minutes for the sedentary.
Twice as many non-exercisers (34 percent) as vigorous exercisers (17 percent) take medicine to help them sleep.
Only 40 percent of vigorous exercisers, as opposed to 46 percent of moderate exercisers, 55 percent of light exercisers and 72 percent of the sedentary reported feeling tired during the day. More than twice as many of the sedentary (14 percent) reported having difficulty staying awake at least once a week while driving, eating or engaging in social activity than did those who exercised (4 to 6 percent).
Just 22 percent of those who sat for less than six hours a day described their sleep quality as "fairly bad" or worse, compared to 25 percent who sat for less than eight hours, 30 percent for those who sat for more than 10.
At Club Julian, Addie Echardt, 52, of McCandless said for her, exercise is always worth it: "I sleep better on the nights I work out than on the nights I don't."
Jack Kelly: email@example.com or 412-263-1476.