浙江省2016高考英语二轮复习专题训练阅读理解（6）_高考复习指南

浙江省2016高考英语二轮复习专题训练阅读理解（6）

　　Exercise also may reduce the risk of heart disease．There seems to be some effect: Most of the heart protection appears to be realized by walking regularly．More intense exercise has been shown to provide only slightly greater benefits．

　　Active people are much less likely to smoke; they’re thinner and they eat differently than people who are less active．They also tend to be more educated, and education is one of the strongest predictors of good health in general and a longer life．As a result, it is impossible to know with confidence whether exercise prevents heart disease or whether people who are less likely to get heart disease are also more likely to be exercising．

　　Still, in rigorous studies in which elderly people were assigned either to exercise or maintain their normal routine, the exercisers were less likely to fall, perhaps because they got stronger or developed better balance．Exercise may prevent broken bones—but only indirectly．

　　And what about weight loss? Lifting weights builds muscles but will not make you burn more calories．Jack Wilmore, an exercise physiologist at Texas A & M University, calculated that the average amount of muscle that men gained after a serious 12-week weight-lifting program was 2 kilograms, or 4．4 pounds．That added muscle would increase the metabolic rate （代谢率） by only 24 calories a day．

　　Exercise alone, in the absence of weight loss, has not been shown to reduce blood pressure．Nor does it make much difference in cholesterol （胆固醇） levels．Weight loss can lower blood pressure and cholesterol levels, but if you want to lose weight, you have to diet as well as exercise．Exercise alone has not been shown to bring sustained weight loss．Just ask Steven Blair, an exercise researcher at the University of South Carolina．He runs every day and even runs marathons．But, he adds, “I was short, fat and bald when I started running, and I’m still short, fat and bald．Weight control is difficult for me．I fight the losing battle．”