Minimum exercise recommendations meant to prevent some chronic illnesses may not be enough to prevent weight gain, a study found.
Adults should do moderate-intensity aerobic activity a minimum of 30 minutes for 5 days a week, or vigorous-intensity activity of 20 minutes for 3 days, each week. To test whether such regimens are also useful for weight control, researchers in Norway conducted an observational prospective cohort study among more than 19,000 people in the Nord-Trøndelag Health Study in the years 1984 to 1986, 1995 to 1997 and 2006 to 2008. Participants were grouped based on physical activity as inactive, below the recommended level, at the recommended level or above it.
Results appeared online April 29 in the British Journal of Sports Medicine.
Men maintaining physical activity above the recommended levels for more than 30 years increased 5.6 kg, while inactive men increased 9.1 kg. Women who did so gained 3.8 kg, while inactive women gained 9.5 kg. Physical activity above the recommendations was associated with 2.1 kg (95% CI, 1.8 to 2.4) less weight gain in men over any 11-year period, compared with inactive people. Women who did so gained 1.8 kg (95% CI, 1.5 to 2.2) less than inactive women.
Compared with inactive, the odds ratio of men gaining meaningful weight of 2.3 kg or more were 0.79 (95% CI, 0.69 to 0.91) and in women was 0.70 (95% CI, 0.60 to 0.81) if exceeding the recommended amount of exercise.
“Although our results showed less pronounced weight gain when exceeding current recommendations, participants in all activity levels gained weight over 22 years,” the authors wrote. “Based on our data, some weight gain throughout adult life seems to be inevitable, but a high level of physical activity reduces the magnitude of weight gain in men and women. Besides, even if physical activity above the current recommendations for physical activity might be needed to prevent unhealthy weight gain, there is a vast body of literature showing that the recommended 150 min of weekly moderate activity lower the risk of chronic diseases and mortality.”