Men's Health: The Battle for Your Body

Fat and muscle are at war -- make sure the good guy wins.

ByABC News
April 26, 2011, 1:17 PM

April 28, 2011— -- The battle goes on whether you're awake or asleep, on the couch or on the treadmill. On one side, the good guy: Muscle. Muscle is like the doorman at your own personal nightclub. It's his job to make you look good, attract the cute girls, and keep out the riffraff. The riffraff, in this case, is a man called Fat.

Fat hates Muscle, and the feeling is mutual. Fat wants to fill your nightclub with all his fat, lazy friends, who will just sit around bumming free drinks, eating all the peanuts at the bar, and scaring the women away. Fat also wants to run Muscle out of town.

You know which side you're rooting for: Muscle burns fat for energy, which is why building and maintaining muscle is the key to losing flab and sculpting a lean, toned body. Muscle boosts metabolism, helping you burn calories day and night. Muscle heightens your testosterone level, keeping aging at bay and your sex drive revving. Muscle helps protect you from heart disease, back pain, arthritis, and depression.Help Muscle win the war against Fat, and you'll triumph over much more than your waistline. The key: firing up your metabolism.

Just what is metabolism? Simply put, it's all the various chemical reactions that happen inside your body 24-7 to keep you alive. Think of your metabolism as your caloric bouncer, ready to throw Fat out of Club You.

Your metabolism isn't an instant-makeover machine, but you can order it to keep an eye out for big fat party crashers and throw them back onto the street. Learn these surprising truths, and you'll help Muscle conquer its flabby nemesis—once and for all.

Truth #1: Burning calories in the gym is (almost) a waste of time

Sure, burning calories is great. But the energy you expend in the gym isn't as big a deal as those LED readouts on the treadmill might make it seem. In fact, we all have three distinct types of "burns" that make up our metabolism. See below.

Burn #1: Basal (Resting) Metabolism -- 60-75%

Your basal metabolic rate, or BMR, accounts for 60 to 75 percent of your overall metabolism. Surprisingly, it represents the calories you burn doing nothing at all. It's fueled by your heart beating, your lungs working to breathe, and even your cells dividing.

Burn #2: Digesive Metabolism -- 10%

This burn results from the thermic effect of food, or TEF. Simply digesting food—converting carbohydrates to sugar and protein to amino acids—typically burns 10 percent of your daily calories. You burn more calories digesting protein than you do digesting carbohydrates and fat—about 25 calories for every 100 consumed, versus zero to 10 for carbs and fat.

Burn #3: Exercise and Movement Metabolism -- 15-30%

This part of your metabolism includes your gym workouts and other physical activities such as jogging or playing softball (called "exercise-activity thermogenesis," or EAT). It also includes your countless incidental movements throughout the day, like turning the pages of a magazine ("non-exercise-activity thermogenesis," or NEAT).

So why is it so hard to lose weight just by exercising? Why do you see so many overweight people in the gym? The answer is simple. Exercise and movement account for only 15 to 30 percent of your fat burn. Up to 85 percent of your calorie burn in a given day has nothing to do with moving your body. But that doesn't mean you should skip the gym--you just need to know how to make exercise work for you. The fact is, exercise can play an important role in preparing Muscle to conquer its greatest threat—Fat, of course.