Fitness Article:
Fighting Obesity With Exercise
By Edmund R. Burke, Ph.D.Perhaps the biggest fitness-related news at the close of the last century involved reports that the United States is experiencing an "epidemic" of obesity, and it is killing some 300,000 persons a year. The Journal of the American Medical Association reported new findings from the U.S. Centers of Disease Control and Prevention that the number of American adults who are obese - 30% or more over their ideal body weight - had increased from about one in eight in 1991 to nearly one in five in 1998. This finding was considered conservative. Other research found 50% of Americans overweight and 22% obese.
It's not as if people aren't trying to do something about it. Nearly 30% of men and 44% of women in America say they are attempting to lose weight. But fully 80% of them are not doing the two things authorities recommend be done in combination: cutting calories and exercising. This brings up three other studies reported late last year that demonstrate how extraordinarily important exercise is in weight control.
Weight loss without dieting. In a study reported by Women's Sports and Fitness, 12 overweight women performed five hour long workouts a week combining cardiovascular and strength training, without changing their eating habits. In eight weeks they lost an average of five pounds, 4% of their body fat and reduced their waist sizes by an average of three inches. Cutting calories would have increased the weight loss.
Easy start. Significant weight loss can he achieved by brief bouts of exercise throughout the day. Researchers at the University of Pennsylvania assigned women who were 20% to 75% heavier than the government's standard to a diet and to 40-minute exercise programs. One group worked out in 10-minute increments spread throughout the day. At the end of six months, this group had lost the same amount of Weight - an average of 26 pounds - as those who worked out in only one session.
Keeping it off. People who have lost large amounts of weight and kept it off tend to exercise twice as much as the federal guideline of 30 minutes a day. A study of 2,800 people who lost an average of 65 pounds and kept at least 30 pounds off for 5-1/2 years found that they exercise at least an hour a day, burning 400 calories.
The American Heart Association has classified obesity as a major cardiovascular disease risk factor, right up there with smoking, lack of physical activity, high blood pressure and high cholesterol. In fact, obesity interacts with those other high risk factors, and is associated with other adverse health conditions like osteoarthritis and diabetes, exacerbating those conditions to make an obese individual subject to further health risks. While there is no data available to show conclusively that obese persons who lose weight live longer, other evidence shows that weight loss contributes to reduction of health risks associated with obesity. Even a ten-percent weight loss provides this benefit, which can be achieved through a regular exercise program. Writing in ACSM's Health & Fitness Journal, Kyle McInnis, Sc.D. gives seven health benefits for reduced weight:
- lower blood pressure
- reduce risk of diabetes
- improve conditions for already diabetic persons
- reduce cholesterol and triglycerides
- raise the level of high-density lipoproteins, the good cholesterol
- reduce need for hypertension and diabetic medications
- reduce the symptoms of arthritis.
Although formal exercise training programs can reduce body weight and fat mass, the changes may be small if a change in diet is not part of the plan. McInnis points out that an energy deficit of 3500 calories a week is necessary to lose a pound of fat, so expending calories at a rate of 250 per session will result in a pound lost every 2-1/2 weeks, assuming no increase in calorie intake. Reducing energy intake to augment that loss, even modestly, will lead to loss of fat rather than muscle tissue, in the end boosting resting metabolism and leading to successful weight maintenance. Without question, it is slow going at first, but consistent exercise combined with consistent reduction of high calorie, high-fat foods will last longer than the effects of diet alone.
An exercise program for an overweight-to-obese person should take into account several factors, says McInnis. To begin, have a pre-participation screening to define any medical conditions and understand how physical activity might affect them. Make a statement of goals, both short- and long term. Figure out how to overcome the desire to quit, and plan how often to assess your progress. Decide on the best environment (home or gym, group or individual, morning or evening) for a physical activity program. Once these factors are addressed, the exercise program can be designed. Start with low- to moderate-intensity exercise for 30 minutes or more. If 30 minutes at one time is too much, use short bouts to accumulate 30 minutes. Choose the most appealing type of exercise, so it will be easier to stick with it. Lastly, keep a journal to show how much time is spent on which form of activity, and make a date to review the diary, perhaps at weight check-in time.
