vineri, 23 decembrie 2011

Fitness is...

     Regular activity has a number of proven, positive health effects, especially on heart health. Vigorous exercise strengthens the heart as a pump, making it a larger, more efficient muscle. Even moderate activity can boost HDL ('good') cholesterol, aid the circulatory system, and lower blood pressure and blood fats. All these effects translate into reduced risk for heart disease, heart attack, and stroke.
     Exercise can also offer other benefits, including strengthened muscles, increased flexibility, and stronger bones, which can help ward off the bone-thinning condition called osteoporosis.
     Regular activity also promises mental-health benefits, like relieving stress and anxiety. It can help you sleep better and renew your energy. If exercise could be bottled, it would be a best-selling potion at the local pharmacy.
          Activity is for Everyone
     Virtually everyone can get health benefits from activity. But every few years, surveys confirm the well-known fact that most people aren't active enough. Unfortunately, we pay for it.
     The reasons for inactivity aren't hard to figure out. Most of us have jobs where we sit most of the time, so chances are limited to be physically active at work. We also rely heavily on modern, labor-saving devices - cars, appliances, and power tools - to spare us manual effort. 
But there's another reason why many people, especially the overweight, avoid activity. Check out the firm, supple bodies shown exercising on television or on magazine covers. They give the impression that exercise is sweaty, strenuous work best reserved for the young, super-fit, and athletic. But the latest research is proving that picture false: benefits can be gained even from low-intensity activity, like gardening. 
          Activity and Weight Management
If you burn more calories than you consume, then you'll shed pounds. For every extra 3,500 calories you spend, you'll drop one pound. Do strenuous exercise, and you'll burn calories in a hurry. And you can burn the same number of calories with gentler activity: You just have to do it longer and/or more often.
If you're not familiar with the number of calories burned during exercise, you may be discouraged when you first learn about it. For instance, if you weigh 150 pounds and go on a brisk, 1-mile walk for 20 minutes, you'll expend about 100 calories, considerably short of the 3,500 calories needed to drop a pound.
     But such efforts add up. If you expend an extra 300 calories a day through activity and reduce your dietary intake another 200 calories, then by the end of a week, you'll have a calorie deficit of 3,500, comparable to a one-pound weight loss. This is precisely the kind of gradual success that experts recommend for long-term weight management.
     Exercise also has other body-slimming effects. It builds muscle and displaces fat. A given volume of muscle weighs more than the same bulk of fat. So your bathroom scale may not record dramatic changes, but your clothes will be looser, and you'll have a trimmer body shape.
     Because exercise builds muscle, it may also help counter a problem caused by dieting. When you reduce calories, your body metabolism may slack off and burn calories more slowly. This makes further weight loss more difficult. But some research suggests regular activity helps correct this slowdown and makes it easier to keep shedding pounds.
          How Activity Affects Calorie Needs
     The more active you are, the more calories you'll burn, which can help with weight loss. And exercise also promotes fat loss and builds muscle. This, in turn, increases your body's metabolic rate, the rate at which you burn calories, even after you've finished exercising.
Weight loss by reducing your calorie intake without activity can have just the opposite effect: it can cause your body to break down muscle, which ultimately lowers your metabolic rate and makes losing weight even harder.
The problem of reducing your calorie intake without exercise is compounded when people go off their diets. Because they've lost muscle, they tend to regain their weight quickly and then some.
     A better approach is to increase activity, which builds muscle, at the same time that you're cutting back on excess calories from food. Physical activity can also reduce stress and regulate your appetite, making it easier to curb the urge to overeat. 
     The amount of energy needed for any activity, whether it's raking leaves or playing a computer game, depends on three factors: your muscle mass, your body weight, and the activity itself. The larger the muscle mass and heavier the body part being moved, the more calories you use. The duration, frequency, and intensity of exercise also count.
   
     

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