YOU on a diet Chapter 7

[Guest guest]

FACTOID Think of exercise as medication. Too much of a stretch? Well, studies show that exercise decreases the risk of depression as well as an antidepressant. Thirty minutes of daily walking has been shown to decrease the risk of breast cancer by 30 percent and increase the rate of survival by 70 percent. Plus, it also improves the survival rates of heart attack victims by 80 percent. Starting with the 1960's, the increase in time that the average American spends watching TV perfectly parallels the increase in the average person's waist size. Besides keeping us from running errands outside, TV frees our hands to engage in mindless eating as we plan for the next commercial-break run to the fridge. This is an especially big problem for kids, who on average watch seventeen hours per week. Sure, protein is

necessary for building and repairing of muscle, but don't fall into the trap of thinking you're not getting enough. To meet your daily protein requirements, you need only two ounces; one small chicken breast includes that amount. Exercise does increase protein needs, but usually not much. more protein in your diet, as we mentioned earlier, does decrease appetite. Besides the muscles you can voluntarily exercise, there are others in your body that you have no control over-such as the ones around your intestines and esophagus. They're involuntary smooth muscles, and they're the ones that no amount of crunches can ever build. Sports drinks may have some of the coolest commercials, but they're necessary only if you exercise for more than sixty minutes. They rehydrate your body faster than water after long periods of exercise because they help you recover muscle power sooner than water does

(because they contain minerals in your body called electrolytes that hasten the absorption of water). But if you drink them regularly or after short workouts, you'll end up consuming more calories than won't get burned off. Doing exercises for a particular body part will not burn fat at that very point. Your body decides where it wants to burn fat, so there's no such thing as spot-reduction through exercise. Otherwise, wouldn't we be seeing people doing double-chin crunches in the gym? Instead, by doing exercises for a specific body part, you're building muscle mass in that area-which, after burning fat, will have the appearance and attributes of lean, strong muscle. Deciding between free weights and weight machines is like trying to decide between salmon and tilapia: They both have their strong points. Fee weights (barbells and dumbbells) help you work on balance because your body has

to work to balance the weights as well as lift them, while machines can help prevent injuries stemming from poor form because they're built in such a way that they force you to use proper form. The supplement coenzyme Q10 is an essential part of your cells that is responsible for energy conversion (it converts glucose to ATP, the energy that powers your cellular functions). In a few studies, CoQ10 improved muscular performance by 10 percent to 30 percent, and it can help protect muscles from oxidative stress. The main challenge is finking pills that really have the CoQ10 promised on the label. Some athletes laud the supplement creatine as a wonderful muscle builder-and the difference between a homer and an out, or the difference between a world record and third place. Some studies show that creatine can increase power and speed as well as cellular energy, but the fact is that most of the gain in muscle

size is due to increased water accumulation. Studies show that a simple sugar and some protein can help muscles recover faster after exercise (think apple with a handful of nuts). As you increase the intensity of your exercise, the typical body utilizes a higher percentage of carbohydrate- fueled energy rather than fat-fueled energy. Some incorrectly interpret this to mean that as you increase exercise intensity, you are no longer burning fat, but burning only carbohydrates. Since the total number of calories burned during higher-intensity exercise is larger than the number of calories burned at lower intensities (even thought a slightly higher percentage may come from carbohydrates than fats), you are almost always using (burning) more total fat than if you worked at a lower intensity. Muscle Makeup Mitochondria create ATP from energy we consume

and feed the muscle fibers. The cells are coupled with tracks and move on one another to shorten (lifting your body) or relax (stretching) . How Much Muscle Do You Have? While some waist-related measurements are easily quantifiable (pounds, waist size, number of pants ripped since 1993), muscle mass is a little trickier to calculate. Sure, you can eyeball yourself in the mirror and see if your abdominals look like an alligator's back. On indirect way to estimate is through knowing your body-fat percentage: The lower your fat percentage, the higher your muscle mass (this percentage can be measured at a gym, or with at-home devices like calipers). The truth is that the amount of muscle mass doesn't matter in terms of health (most of us have between twenty and thirty pounds of muscle) and waist size does

matter. What is important is that you do enough strength-building exercise to maintain your muscle mass, which otherwise decreases as you age. Asian Invasion Wake up any morning in Beijing, China, and you see hundreds of people of all ages greet the sun with awkward movements. They appear to be wrestling demons in the air, but they're practicing tai chi-a form of exercise used to balance, center, and relax the body. You can use tai chi as a meditative form of exercise or as a way to improve your balance. Have You Gone Too Far? Exercising is like nuts in at least one way: There is such a thing as too much of a good thing. While exercise

has more pluses than a math workbook, you can take it too far. Burning more than 6,500 calories a week through exercise (that's roughly thirteen hours) or doing more than two hours in a row of cardiovascular training not only can stress your joints (depending on the exercise), but it also appears to be the level at which you induce too much oxidative sress in your body, and that decreases your longevity.