How Much Physical Activity is Needed for Successful Weight Management?

There is basically a threshold level of physical activity that once you meet or exceed it—tons of research shows a huge difference in keeping the weight you lost off. That threshold level is 2,000-calories a week. Research consistently shows that successful maintainers expend 2,000 to 3,500+ calories per week in physical activity.

Here's a representative study of the difference in results I'm talking about. The Moderate PA group exercised more than double the Low PA group with no difference in percent weight regained 2-years post weight loss. Both the Low and Moderate exercisers regained three-quarters of the weight they lost before starting maintenance. The High PA group however kept off three-quarters of the weight they lost before starting maintenance.

So while the Moderate PA group got the recommended level of PA needed to substantially decrease disease risk (reducing the risks of heart disease, type 2 diabetes and several types cancer), it had little effect on weight loss maintenance. [Enlarge chart]

Walking is the most popular choice used to burn activity calories.

Here's a simple formula for how many calories you burn per mile (for walking paces of 2.5 to 3.5 mph):

[Your Weight ÷ 150] x 100

Example: [175 ÷ 150=1.1666] x 100 = 116 calories per mile

Therefor, at 175-pounds you would need to walk ~2.5-miles per day to hit 2,000-calories.

Here's the math: [(2,000 ÷ 116 = 17.25) ÷ 7 days = 2.5]

If you follow Tier-2 and 3 of the (current) 2008 Physical Activity Guidelines for Americans you will hit the 2000-calories/week target for successful weight management. Here are the recommendations for adults:

• [Tier-1] For substantial health benefits, adults should do at least 150 minutes (2 hours and 30-minutes) a week of moderate-intensity, or 75 minutes (1 hour and 15-minutes) a week of vigorous-intensity aerobic physical activity, or en equivalent combination of moderate- and vigorous-intensity aerobic activity. Aerobic activity should be performed in episodes of at least 10 minutes, and preferably it should be spread throughout the week.
• [Tier-2] For additional and more extensive health benefits, adults should increase their aerobic physical activity to 300 minutes (5 hours) a week of moderate-intensity, or 150-minutes a week of vigorous-intensity physical activity, or an equivalent combinationn of moderate- and vigorous-intensity activity. Additional health benefits are gained by engaging in physical activity beyond this amount.
• [Tier-3] Adults should also include muscle-strengthening activities that involve all major muscle groups on 2 or more days a week.

References:

1. Jakicic JM, et al. Appropriate intervention strategies for weight loss and prevention of weight regain for adults. American College of Sports Medicine Position Stand. Med Sci Sports Exerc 2001;33:2145-2156.
2. IOM Dietary References Intakes for Energy, Carbohydrates, Fiber, Fat, Protein and Amino Acids: A Report of the Panel on Macronutrients, Subcommittees on Upper Reference Levels of Nutrients and Interpretation and Uses of Dietary Reference Intakes and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. National Academies Press: Washington, DC, 2002.
3. Jakicic JM, et al. Effect of exercise duration and intensity on weight loss in overweight, sedentary women: a randomized trial. JAMA 2003;290:1323-1330.
4. Donnelly JE, et al. The role of exercise for weight loss and maintenance. Best Pract Res Clin Gastroenterol 2004;18:1009-29.
5. Catenaccie Va, et al. Physical Activity Patterns in the National Weight Control Registry. Obesity 2008;16(1):153-161.
6. Saris WHM, et al. How much physical activity is enough to prevent unhealthy weight gain? Obes Rev 2003;4:101-114.
7. 2008 Physical Activity Guidelines for Americans.