The common thought is that relatively vigorous exercise is necessary most days per week in order to lose weight. However, some new research suggests that even mild exercise is beneficial because it might prevent development of fat cells, even if it does not help you loose a lot of weight. In fact, even though dramatic weight loss is not seen, research suggests that even relatively little exercise reduces the amount of intra-abdominal (stomach) fat.
Guidelines on Exercise
The guidelines available from the US Department of Health and Human Services recommend that most adults should avoid inactivity. (US Department of Health and Human Services. 2008 Physical Activity Guidelines for Americans. Washington, DC: US Government Printing Office, 2008.) Specifically, the HSS recommends that most adults perform at least 30 minutes of moderate-intensity exercise per day, five times per week. This should be the baseline for most adults, and is a good recommendation. However, to lose weight, the HSS recommends that most Americans increase their moderate-intensity activity to one (1) hour per day, five days per week.
Research on Exercise and Weight Loss
Some interesting research published in 2007 suggests that exercise may affect the development of some adult stem cells (Rubin, C. T., et al. Adipogenesis is inhibited by brief, daily exposure to high-frequency, extremely low-magnitude mechanical signals. Proceedings of National Academy of Sciences, 2007: 17879-17884). Ruben and co-researchers wanted to know how exercise suppresses the development obesity and type II Diabetes. The team tested how low-magnitude mechanical signals†affected the development of Mesenchymal Stem Cells which are present in all adults, and can turn into various types of body cells – including fat, muscle or bone cells. Ruben and team performed an experiment on mice, where the mice were placed on a platform that vibrated very gently for 15 minutes per day and compared them to the mice that were placed on a platform that did not vibrate. The vibrations these mice experienced (by their accounts) were three times less than those experienced during typical exercise.
Their findings were amazing. After 15 weeks of the experiment, the mice on the vibrating platform had 27% less fat. And, that is without the mice doing any additional exercise (after all, the only difference was whether or not the platform vibrated or not). While this research does not splash cold water on the current thought of the necessity of exercise, it is clear that some kind of movement is necessary for successful weight loss because there seems to be a mechanical affect of exercise on the development of new fat cells.
When we couple it with numerous other studies that suggest that exercise is helpful in weight loss, (as well as providing other health benefits), it is clear that most people will benefit from a moderate amount of daily exercise (or what is suggested by the Department of Health and Human Services publication).
Want even more reasons to talk to your physician and start an exercise program? OK. Try this. In a Study of 173 sedentary, overweight women (average age 61, weight 205 lb.) Irwin and co-researchers found that the women lost an average of 2% of their weight (about 3 pounds). But, they lost an average of 5% of their stomach fat (Irwin M. L., et al. Effect of Exercise on Total and Intra-abdominal Body Fat in Postmenopausal Women. JAMA (Journal of the American Medical Association, 2003: 323-330). These are results that you can really measure – the Irwin study reports about ½ inch around the waist and about ¾ of an inch around the hips. Now, before you go and pooh-pooh only 3 pounds and ½ inch, let us tell you how this was done. The study classified it as moderate-intensity sports/ recreational activity, averaging 3.5 days per week and [35 minutes per day]. Translation: the girls went for a walk!
Still not sold? According to the Schmitz study, American women aged 25 – 44 years old gain between 1 – 2 lbs. per year, most of which is fat. (Schmitz, K H., et al. Strength Training and Adiposity in Premenopausal Women: Strong, Healthy and Empowered Study.†American Journal of Clinical Nutrition, 2007: 566-572). Now, the Schmitz study was not using walking – the exercise group was being led by fitness trainers on gym equipment. But, the end result? After one year, body fat dove 4.36%, the women lost an average of 8 lbs. of fat, including some of the worst “intra-abdominal fat (this is the fat that surrounds your organs and is one of the contributors to cardiovascular disease).
Conclusions on Exercise
Now, something tells us that anyone could find ½ hour in the day to take a walk with a spouse or a friend. If one is really adventurous, she could add to it by extending it to 1 hour at a time, or to 5 days per week… or taking small along when you go. In his book, Dr. Stutman claims that taking along handweights burns 50% more calories (Fred Stutman, MD. 100 Best Weight-Loss Tips. Philadelphia, PA: Medical Manor Books, 2005). So, talk to you physician about starting your exercise program, and do it!
Additional Resources
Exercise category on 20BMI.com
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