健康——减肥的关键
Perhaps like most Americans you have some extra pounds to shed. You may even have tried a fad diet or two, but found yourself right back where you started. The key to weight loss is regular physical activity. And surprisingly, you don't have to give up eating or make the gym your second home to see long-term, positive effects.
或许象多数美国人那样，您需要减肥。流行的节食方法对您可能并不起作用。下面将告诉您减肥的秘诀：不需要放弃美食，不用整天呆在健身房里运动，只要……
One: Aerobic Activity
一、有氧运动
Your body needs a certain amount of energy to maintain basic functions such as breathing, blood circulation and digestion. The energy required to keep your organs functioning is referred to as the resting or basal metabolic rate.
人体往往需要一定的能量，需要这些能量来……
Any time you are active, additional energy is required. It is obtained from glycogen (carbohydrates) and fat stored in the blood, liver, and muscles. The key to losing weight is to draw on the fat rather than on the carbohydrate reserves.
一旦运动的时候，需要的能量就会更多。是单纯消耗能量就能有效减肥吗？减肥的关键是……
Which of the two energy sources you use depends on the intensity and duration of your activity. The higher the intensity, the more your body will pull from the stored carbohydrates. The lower the intensity, the more your body will rely on fat as its fuel.
额外所需的能量主要来自人体储存的两类资源，消耗哪类能量资源取决于……
Aerobic exercise (any activity that increases oxygen intake and heart rate) is most effective for weight loss. When you perform aerobic activities you repeatedly contract large muscle groups such as your legs and arms. Walking, running, rollerblading, swimming, dancing, and jumping jacks are all forms of aerobic activity.
有氧运动是最有效的减肥运动，有氧运动项目包括……
Surprisingly, if your aerobic activity is low to moderately intense and of long duration, you will burn more fat than if you had participated in a short burst of high-intensity exercise. In short, a brisk 30-minute walk will burn fat while a 100-yard sprint will burn glycogen.
有氧运动效果很神奇，30分钟轻快漫步消耗的能量相当于……
