Physical Activity and Weight Management
Most individuals know that physical activity and exercise is important for weight loss and weight maintenance, but really do not understand why. Let's take a look at this further.
First, what is the difference between physical activity and exercise?
Physical activity is any bodily movement; it results in energy expenditure. Examples of physical activity include walking and doing housework. Any physical activity is associated with health benefits.
Exercise is a subset of physical activity that is generally more formalized and results in greater exertion. Examples of exercise include your standard gym workout and bike riding. Besides the health benefits associated with physical activity, exercise is also associated with improvement in physical fitness.
You can see that there is overlap in the definition. However, the critical component is that you just MOVE!
What are the effects of physical activity and exercise?
Both will increase energy expenditure (burn more calories) however, this does not necessarily translate into weight loss. In fact, most studies show only a small weight loss associated with increased physical activity or an exercise program.
In a published study (J Clin Endocrinol Metab, April 2010, 95(4):1609-1616) physical activity tended to:
- Increases hunger in the fasted state
- Improved satiety ("fullness") in response to meals
- Improved sensitivity to internal hunger cues
Thus, it is possible that exercise, in certain situations, can increase body weight. However, in a weight reduced state (after you have lost weight), studies show that regular daily exercise is critical in maintaining weight loss.
Medically, increased physical activity generally has the following positive effects on medical conditions
- Lowers blood sugar
- Improves blood pressure
- Improves blood lipids
- Improvement in sense of well-being
How much physical activity is needed for either health benefits or for weight management/weight reduction?
For general health benefits, 30-45 minutes of moderate physical activity (such as brisk walking) be undertaken most days of the week (the equivalent of 2.5 hrs of activity weekly). Some activity is better than none, the activity does not have to be done in one bout, and the more performed, generally the better the outcome.
For weight management, it requires the eqivalent of at least 60 to 90 minutes of brisk walking daily. This has been derived from the work of Drs. Jim Hill and Rena Wing at the The National Weight Control Registry. Again, the activity does not have to be done in one bout, but it takes a lot of physical activity to lose and maintain weight loss.
Physical activity is an integral part of any healthy lifestyle and is a virtual necessity for weight management. Although physical activity and exercise generally results in only a small weight loss, it is essential for weight maintenance. From clinical studies, it generally requires the equivalent of 60-90 minutes of brisk walking daily to maintain weight loss.
Updated: 27 December 2011
Copyright © 1996 -2011 Michael D. Myers, M.D., Inc.
All rights reserved.
The above information is for general purposes only and should not be construed as definitive or binding medical advice, diagnosis or treatment. Because each person is medically different, individuals should consult their own personal physicians for specific information and/or treatment recommendations.