The recommended amounts of exercise vary from group to group, so figuring out how much you need can be tricky. The 2008 US federal recommendation is at least 150 minutes of moderate-intensity physical activity per week in order to obtain “substantial health benefits.” The Institute of Medicine recommends almost three times this amount—420 minutes per week, or 60 minutes per day.
The new study asked a different question: How much exercise prevents weight gain? Using information drawn from more than 34,000 women who took part in the Women’s Health Study over a 15-year period, researchers measured the amount of exercise that the women were doing and how much weight they gained over the years.
The women were grouped into three exercising categories:
Those in the groups who exercised less than 420 minutes per week gained similar amounts of weight, and higher levels of physical activity only seemed to protect thinner women from gaining weight. Women who were overweight or obese were not able to keep from gaining weight by exercising alone. Since only those women of normal weight were able to keep the pounds off with exercise, the importance of controlling caloric intake is essential for weight maintenance in heavier women.
“The 2008 federal recommendation for 150 minutes per week, while clearly sufficient to lower the risks of chronic diseases, is insufficient for weight gain prevention.” they concluded. “Sustaining high levels of physical activity is needed to successfully maintain normal BMI [body mass index] and prevent weight gain,” said the researchers. Since only those women of normal weight were able to keep the pounds off with exercise, the importance of altering the diet to help reduce caloric intake is essential for weight maintenance in heavier women.
So why bother exercising if it’s not going to help keep the pounds off? For many people, exercise is a vital part of a weight-loss program, enabling them to lose more than they could by dieting alone. And maintaining or losing weight is just one of the many benefits that exercise confers. Even if you are overweight, exercise:
Some exercise is better than none at all. So make a commitment to your health and get moving whenever you can. If you need to shed a few pounds, try these tips: