The Importance of Burning Calories

Brian J. Sharkey and Steven E. Gaskill's Fitness & Health emphasizes the importance of regular, vigorous physical activity that burns calories.

Physical activity can be measured in terms of how many calories are consumed while doing it. When you exercise, your muscles burn fuel: sugars derived from food. They thus produce heat.

A "calorie" as commonly spoken of is actually, a kilocalorie, the amount of heat it takes to raise the temperature of 1 kilogram of water — equal to 1 liter — 1 degree centigrade. Hence, when your muscles work, the heat they give off is measured in kilocalories, or, in everyday parlance, calories. We accordingly speak of "burning calories."

In the section titled "Activity Reduces the Risk of Coronary Artery Disease" (p. 15ff.), Sharkey and Gaskill show how important calorie-burning exercise is to reducing the chances that you will ever have problems with coronary artery disease. CAD is "the nation's number-one killer for men and women," because it's what causes atherosclerosis and leads to burst blood vessels and blood clots in the heart." When that happens, you have a heart attack, a.k.a. myocardial infarct.

Scientific studies show, say Sharkey and Gaskill, that "the active life can slow, stop, or reverse atherosclerosis" (p. 17).

In one study (p. 18), Harvard alumni who burned 1,000 to 2,500 calories per week while exercising were only 71 percent as likely to die from coronary artery disease as those who burned less than 1,000 calories per week. The minimum level of activity to produce those results, 1,000 calories per week, is the equivalent of walking 30 minutes per day.

Those who burned more than 2,500 calories per week reduced their likelihood of CAD-related death to just 54 percent (!) of that of the less-than-1,000-calories control group. 2,500 calories per week is equivalent to 25 miles of jogging per week, since each mile of jogging uses up approximately 100 calories.

Calculate Your Activity Index!

Your Activity Index is a number that can tell you whether you are getting enough exercise, by telling you which of six fitness categories you are in. Click here to calculate it.

The Activity Index is also featured on this Web page, along with various fitness, strength, and endurance tests: a one-mile walk test, using a heart rate monitor; the Rippe running test; a three-mile hike test (with pack) from the U.S. Forest Service; the Montana bicycle test; the maximum bench press, a test of strength; the rapid sit-up endurance test; the push-up test of dynamic strength; the vertical jump test; and the 300-meter sprint test.

Get in Shape, America!

To help make health care more affordable and available, President Obama wants to help pay for a 10-year $630-billion health-care reserve fund by limiting the current tax break for itemized deductions to 28 percent for families making more than $250,000 (see Obama's Plan to Reduce Charitable Deductions for the Wealthy Draws Criticism). The reduction in how much the wealthiest taxpayers could deduct would raise $318 billion of the total of $630 billion over the course of a decade.

It's a good idea ... and here's an even better one!

According to Brian J. Sharkey and Steven E. Gaskill's excellent book Fitness and Health (Sixth Edition), Americans are individually and collectively paying a high price for being inactive, sedentary, and generally out of shape. The book says:

Activity can reduce heart disease and control heart disease risk factors — elevated cholesterol, high blood pressure, diabetes, and obesity. Inactivity contributes to a substantial number of deaths annually and costs $94 billion a year in medical expenses in the United States" (p. 3).

Whoa! $94 billion a year down the commode, just because Americans aren't fit?!??

Clearly, if shaving income tax deductions on the well-to-do can raise a much-needed $31.8 billion per year to help offset the spiraling costs of health care, while getting everyone in shape can lower those costs by three times that amount, then we need to get everyone in shape, now!


The dollar cost cited by Sharkey and Gaskill at $94 billion comes from a study called "Economic costs of obesity and inactivity," by Graham A. Colditz, summarized here. According to the summary, we waste $70 billion per year due to the epidemic of obesity, defined as having a body mass index greater than 30.

Body mass index is a measure of body fat based on height and weight. You can calculate yours here. (I'm 6'1" tall and weight 185 lb., so my BMI is 24.4. That puts me at the top end of the "normal weight" category, just under the "overweight" bracket. The calculator shows that if my weight rose just five pounds to 190, I'd enter the latter bracket. If my weight rose all the way to 228, I'd be obese. Oh, and by the way ... the BMI calculation is independent of gender; it's the same for women as for men.)

The other $24 billion of the $94 billion price tag cited by Colditz represents the "direct costs of lack of physical activity" ... inasmuch as there are definite health costs associated with a sedentary lifestyle, even when the individual is not so overweight as to be obese.


Sharkey and Gaskill say that "as many as 250,000 lives are lost annually because of lack of regular, moderate physical activity" (p. 3). (This figure comes from "Physical Activity and Health: A Report of the Surgeon General," accessible here.) 40,000 die in auto accidents, 30,000 from unprotected sexual intercourse, and 20,000 from drug overdoses. That's a total of 90,000 tragedies that everyone knows are tragedies. But there are almost three times as many unnecessary deaths due to our being such couch potatoes, and most of us don't even realize how doubly tragic they are.

Tragedy #1: Someone dies much too young.

Tragedy #2: Tragedy #1 could have been avoided if he or she had only exercised regularly; ate a healthy diet; avoided tobacco, drugs, and (too much) alcohol; etc.

So come on America, let's get fit!