As Covert Bailey, biochemist and well-known lecturer in the study of obesity once said; "The ultimate cure for obesity is exercise"

Enough said, on to Chapter 4...

But seriously, there is more to know about exercise for weight loss than you may think. Believe it or not, some people exercise ineffectively. Some people are working so hard at it, they are not getting anywhere at all.

A person's total daily caloric output is the sum total of the energy required in resting metabolism, thermal effect of food, and the calories burned during physical activity. Let's look at each of these factors and how it relates to weight loss.

Resting metabolism

Scientists would define metabolism as the chemical reactions that make the energy in foods available to the various physiological systems of the body. For instance, energy is required for muscular activity, the growth of skin, hair, nails, maintenance of body temperature, and even absorption of food from the intestinal tract. A way to measure the rate of metabolism is to measure the rate at which oxygen is utilized by the body. This is called basal metabolic rate, or simply BMR (the terms basal metabolic rate and resting metabolic rate are used interchangeably). It acts as "the body's thermostat," much like the thermostat in your house. Resting metabolic rate accounts for approximately 60-75 percent of daily caloric output.

Also affecting resting metabolism is the influence of body size. BMR is proportional to the surface area of the body, in that larger individuals burn more calories than smaller individuals for similar activities. Differences in body composition also affect BMR. Fat tissue is metabolically less active than muscle or lean body mass. Athletes with greater muscle development show a greater increase in metabolism over the non-athletic individual. Muscle accounts for approximately 20 percent of resting metabolism. Women, who have more fat in proportion to muscle than men, have metabolic rates 5-10 percent lower than men of the same weight and height. When based on the same amount of lean body mass, metabolic rates for men and women are similar. The same phenomenon is observed with aging. In general, as people age, lean body mass decreases with increases in fat-mass. A 2 percent decrease in BMR with every 10 years of life is usually observed through adulthood.

Putting this information together, we can conclude that in the overweight person, there is too much body fat and not enough lean muscle mass. How do we change the ratio of fat to muscle? Some people believe that we can turn fat into muscle and vice versa. This is not true. Muscle tissue is made up of long protein-like fibers, whereas fat tissue is round receptacles designed to store fat. Excess calories in the diet causes fat cells to grow in size as they store more fat. Conversely, fat cells shrink when you burn more calories than you eat. Muscle fibers increase when worked (hypertrophy), and muscle fibers decrease when not used (atrophy).

Physical activity

Physical activity can have the most profound effect on caloric output. On average, physical activity accounts for 15-30 percent of total caloric output. Most of us can generate substantial increases in metabolism (up to 10 times the resting value), during sustained exercise such as running and cycling. Bottom line: the more physically active the person, the more active their metabolism.

Boost Your Metabolism and Burn Fat

Boost Your Metabolism and Burn Fat

Metabolism. There isn’t perhaps a more frequently used word in the weight loss (and weight gain) vocabulary than this. Indeed, it’s not uncommon to overhear people talking about their struggles or triumphs over the holiday bulge or love handles in terms of whether their metabolism is working, or not.

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