While an estimated 66% of US adults overweight or obese, only a mere 0.5% of the commuting public age 16 or over riding a bicycle on a regular basis.  Anne C. Lusk, from Harvard School of Public Health (Massachusetts, USA), and colleagues assessed the association between bicycle riding and weight control in women.  The team examined data collected on 18,414 premenopausal women, who were free from chronic diseases such as diabetes, cancer, or cardiovascular disease, participating in the Nurses' Health Study II.  Observing that the subjects gained an average of 9.3 kilograms (20.5 pounds) over the 16-year study period, the researchers found that those normal-weight women who were bicycling more than four hours a week in 2005, irrespective of their physical activity level in 1989, were 26% times less likely to gain more than 5% of their initial body weight. Overweight and obese women who were bicycling just two or three hours a week were 56% times less likely to gain weight.  The researchers conclude that: “Bicycling … is associated with less weight gain and an inverse dose-response relationship exists, especially among overweight and obese women.”