Exercise & Weight Loss Truth

The U.S. Department of Health and Human Services estimates that nearly one-third of adults are obese, defined as having a body mass index, or BMI, of 30 or more. Although weight loss has become a near obsession, myths persists about the most effective way to produce a lean, healthy body. Since an ineffective weight loss program is likely to result in discouragement or even despair, it's important to know how to do it right.

Caloric Intake and Weight Loss

When you eat, you take in calories. When you exercise, even by breathing, you burn calories. If you take in more calories than you burn, you gain weight. If you burn more calories than you take in, you lose weight. Each person has a particular level of caloric intake that is necessary to maintain current weight, depending on gender, height, weight, age and level of physical activity; see Resources section to calculate your own caloric requirements.

Burning Calories

Different activities burn different amounts of calories per hour. For example, hiking at moderate intensity burns about 370 calories an hour, while jogging at 5 miles per hour burns about 590, according to the Department of Health and Human Services. Since 1 pound of fat is equal to 3,500 calories, you need a lot of exercise to lose weight without reducing your caloric intake.

Localized Weight Loss

"Spot reduction"--reduction in the amount of fat in a particular part of the body in response to concentrating exercise on that part--is impossible, according to Michael Carrera, Professor Emeritus of Health Sciences at Hunter College of the City University of New York and Natasha Vani, Director of Physical Activity at Newtopia Inc. Doing 200 calories worth of sit-ups is no more likely to reduce stomach fat than doing 200 calories worth of jogging. Where you lose weight first is determined by your genes, not by the type of exercise you perform.

Muscle vs. Fat

The U.S. National Institute of Health and Human Services defines obesity in terms of BMI, but an individual's ideal BMI depends not only on height and weight, but also on body frame and muscle-to-fat ratio. Contrast an obviously obese person, for example, with a bodybuilder of the same height and weight. The body builder will look and feel healthier, and will also look smaller because muscle is denser than fat. One of the best ways to gain muscle mass is by weightlifting. In addition to building muscle mass, weightlifting burns calories and, during the muscle repair stage between workouts, diverts calories from padding fat reserves to building new muscle.

Exercise vs. Diet

Losing weight through diet alone is harder than losing weight through diet and exercise. And even if you reach your goal weight through diet alone, your muscle-to-fat ratio may not have changed very much. On the other hand, losing weight through exercise without dieting takes more exercise than most people have time to perform, and for some people it can involve serious health risks. Accordingly, the most effective weight loss program involves both diet and exercise. Exercise should include both aerobic exercise and weight training, so you lose weight and lower your body-fat ratio.