第 9 题

1The benefits of regular exercise are well documented but there’s a new bonus to add to the ever-growing list. New researchers found that middle-aged women who were physically fit could be nearly 90 percent less likely to develop dementia in later life, and as they did, it came on a decade later than less sporty women.

2Lead researcher Dr. Helena Horder, of the University of Gothenburg in Sweden, said : "These findings are exciting because it’s possible that improving people's cardiovascular （心血管）fitness in middle age could delay or even prevent them from developing dementia. "

3For the study, 191 women with an average age of 50 took a bicycle exercise test until they were exhausted to measure their peak （最大值的） cardiovascular capacity. The average peak workload was measured at 103 watts.

4A total of 40 women met the criteria for a high fitness level, or 120 watts or higher. A total of 92 women were in the medium fitness category; and 59 women were in the low fitness category, defined as a peak workload of 80 watts or less, or having their exercise tests stopped because of high blood pressure, chest pain or other cardiovascular problems.

5These women were then tested for dementia six times over the following four decades. During that time, 44 of the women developed dementia. Five percent of the highly fit women developed dementia, compared to 25 percent of the women with medium fitness and 32 percent of the women with low fitness.

6"However, this study does not show cause and effect between cardiovascular fitness and dementia, it only shows an association. More research is needed to see if improved fitness could have a positive effect on the risk of dementia and also to look at when during a lifetime a high fitness level is most important. " She also admitted that a relatively small number of women were studied, all of whom were form Sweden, so the results might not be applicable to other groups.