Moderate-intensity exercise reduces the incidence of colds among postmenopausal women

The study: Am J Med. 2006 Nov;119(11):937-42. Chubak J, McTiernan A, Sorensen B, Wener MH, Yasui Y, Velasquez M, Wood B, Rajan KB, Wetmore CM, Potter JD, Ulrich CM. Fred Hutchinson Cancer Research Center, Cancer Prevention Program, Seattle, Wash 98109-1024, USA.

Purpose: Our aim was to assess the effect of a moderate-intensity, year-long exercise program on the risk of colds and other upper respiratory tract infections in postmenopausal women.

Subjects: A total of 115 overweight and obese, sedentary, postmenopausal women in the Seattle area participated.

Methods:: Participants were randomly assigned to the moderate-intensity exercise group or the control group. The intervention consisted of 45 minutes of moderate-intensity exercise 5 days per week for 12 months.
Control participants attended once-weekly, 45-minute stretching sessions.
Questionnaires asking about upper respiratory tract infections in the previous 3 months were administered quarterly during the course of the year-long trial. Poisson regression was used to estimate the effect of exercise on colds and other upper respiratory tract infections.

Results: Over 12 months, the risk of colds decreased in exercisers relative to stretchers (P = .02): In the final 3 months of the study, the risk of colds in stretchers was more than threefold that of exercisers (P = .03).
Risk of upper respiratory tract infections overall did not differ (P = .16), yet may have been biased by differential proportions of influenza vaccinations in the intervention and control groups.

Conclusions: This study suggests that 1 year of moderate-intensity exercise training can reduce the incidence of colds among postmenopausal women. These findings are of public health relevance and add a new facet to the growing literature on the health benefits of moderate exercise.

"Exercise, especially prolonged or very strenuous exercise after infection, typically can make that infection very severe," Kohut says. Kohut says they know that being healthy helps you fight off sickness, but they want to find out more about the impact of exercise in holding off the flu.

She says they will be looking to see if exercise makes it tougher for the virus to attach to the lungs of mice who have exercised. Kohut says they already have some evidence that different parts of the immune system are enhance by exercise, and they want to find out more how that works. The study is part of a five-year project by I.S.U. researchers, funded by the National Institutes of Health.

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