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Morning
Exercise May Make Sleep Easier
Older women who often have trouble sleeping may want to
consider a little workout in the morning for a better rest
at night.
Morning exercisers had fewer complaints about a bad night's
sleep and those who stretched in the morning had somewhat
better sleep, a new study found. Women who exercise in the
evening, on the other hand, were more likely to be up at
night.
The women didn't need much morning activity to get the benefit.
"It's like doing a brisk walk," said researcher
Anne McTiernan. "Nobody is saying people have to be
athletes and do marathons."
The scientists at Fred Hutchinson Cancer Research Center
in Seattle drew their data from a larger study of the effects
of exercise in reducing the risk of breast cancer. Because
the study included survey questions on sleep, the researchers
could examine an issue that was not part of the original
project. McTiernan is principal investigator of the cancer
study as well as senior researcher on the sleep project,
whose findings were published in the November issue of the
journal Sleep.
Women in the sleep study were cancer-free and postmenopausal,
ages 50 to 75, overweight or obese, and not exercising at
the start of the project. Eighty-seven were placed in the
exercise program and 86 in the stretching program. Both
groups were followed for a year. Researchers compared how
well the women reported sleeping before the study started
and afterward.
Women in the exercise program did at least 45 minutes of
moderate walking or riding an exercise bike five days a
week at an exercise facility or on their own. Those who
were stretching did an hour once a week under the supervision
of an exercise physiologist, and stretched 15 to 30 minutes
three times a week on their own. Fifty-five percent of all
the women did their activity in the morning.
Although the exercise program was about 15 minutes a day
more than federal officials recommend as the minimum for
healthful exercise, it's still not a lot, McTiernan said.
The heart rates of the exercisers were no higher than they
would get in a brisk walk, she said.
How the women did in their programs was compared with their
ratings of their ability to sleep, including whether they
used sleep aids such as pills or alcohol, whether they felt
they were sleeping soundly and through the night, and whether
they fell asleep during quiet activities.
Women who exercised averaged 70 percent better sleep and
women who stretched averaged 30 percent better sleep, the
study found.
The study did not look for reasons why exercise in the morning
was good for a night's rest while exercise at night was
not, or why stretching would help at all.
The researchers suspect that exercise in the morning might
set the women's body clocks for a day of activity and a
night of sleep, while exercise at night might push back
the sleep part of the sleep-wake cycle. They speculate that
the stretches might have improved sleep by making the women
more flexible and relaxed.
Exercise also increases activity hormones and creates lactic
acid as a byproduct, and both can make a body more restless,
said Edward Stepanski, director of the Sleep Disorders Service
and Research Center at Rush University Medical Center in
Chicago. Similarly, exercise raises temperature, while sleep
requires a slight drop in temperature, said Stepanski, who
was not part of the Fred Hutchinson study.
As for why exercise might be better in morning, Stepanski
also suspects a change in circadian rhythm. Finding out
whether morning exercise benefits the body clock would be
an interesting follow-up study, he said.
Article Source: Reuters Health
Article Author: N/A
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