Bicycle riding, walking, and weight gain in premenopausal women.

BACKGROUND To our knowledge, research has not been conducted on bicycle riding and weight control in comparison with walking. Our objective was to assess the association between bicycle riding and weight control in premenopausal women. METHODS This was a 16-year follow-up study of 18,414 women in the Nurses' Health Study II. Weight change between 1989 and 2005 was the primary outcome, and the odds of gaining more than 5% of baseline body weight by 2005 was the secondary outcome. RESULTS At baseline, only 39% of participants walked briskly, while only 1.2% bicycled for more than 30 min/d. For a 30-min/d increase in activity between 1989 and 2005, weight gain was significantly less for brisk walking (-1.81 kg; 95% confidence interval [CI], -2.05 to -1.56 kg), bicycling (-1.59 kg; 95% CI, -2.09 to -1.08 kg), and other activities (-1.45 kg; 95% CI, -1.66 to -1.24 kg) but not for slow walking (+0.06 kg; 95% CI, -0.22 to 0.35 kg). Women who reported no bicycling in 1989 and increased to as little as 5 min/d in 2005 gained less weight (-0.74 kg; 95% CI, -1.41 to -0.07 kg; P value for trend, <.01) than those who remained nonbikers. Normal-weight women who bicycled more than 4 h/wk in 2005 had a lower odds of gaining more than 5% of their baseline body weight (odds ratio, 0.74; 95% CI, 0.56 to 0.98) compared with those who reported no bicycling; overweight and obese women had a lower odds at 2 to 3 h/wk (odds ratio, 0.54; 95% CI, 0.34 to 0.86). CONCLUSIONS Bicycling, similar to brisk walking, is associated with less weight gain and an inverse dose-response relationship exists, especially among overweight and obese women. Future research should focus on brisk walking and greater time spent bicycling.