People know it’s important to avoid excessive weight gain as they get older, and that exercise is a key to success in this regard. But until recently, scientists had published surprisingly few studies purporting to quantify the impact of habitual exercise on weight gain over the long haul.

Arlene Hankinson and her colleagues at Northwestern set out to do just that. Using data from a prospective follow-up study, Hankinson’s group showed that men who were able to maintain high activity levels over an extended period gained 6 fewer pounds, and 5 fewer centimeters of waist circumference than those in the lowest activity group. Women in the highest activity group gained 13 fewer pounds and nearly 7 centimeters less around their waists.

To reach these conclusions, the scientists examined data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, which is a 20-year longitudinal study that began in 1985. CARDIA included complete historical data for 3,554 men and women from Chicago, Birmingham, Minneapolis and Oakland. Enrollees were 18 to 30 years old at study onset. 

During each follow-up visit, CARDIA enrollees completed questionnaires regarding their activities and exercise habits. Each activity had been assigned a numerical score ranging from 108-288 by the scientists. Activity scores were summed for each individual to yield a total score. (more…)