单项选择题
| It is clear that some people who
participate in exercise training will develop injuries to their bones, muscles,
and joints (关节). Despite unfounded reports in the mass media of extremely high
injury rates among adult exercisers, there have been few good studies of
exercise injuries in populations. One of the difficulties in performing such
studies has been the need to identify both the number of cases and the number of
people at risk for injury. In other words, it is difficult to know the number of
individuals injured and the total number of individuals exercising in the
population. But these two figures are necessary in order to calculate (统计) tree
injury rates. Normally, injury is defined as an accident that causes a person to
stop exercising for at least one week. The best available studies on injury
rates show that about 25 to 30 percent of adult runners become "injured" (based
on the above definition) over the course of a year. More serious injuries
include those for which the injured person seeks medical care. If only they are
considered, injury rates are much lower, perhaps in the range of I percent per
year. Little is known about the causes of exercise injuries. One factor that has been linked to injury is the amount of exercise; for example, individuals who run more miles are likelier to be injured than those who run fewer miles. Factors such as age, sex, body type, and experience have not been shown to be associated with risk of injury. It seems logical that structural abnormalities, sudden increases in training intensity, and types of equipment used are likely to be related to injury risk. However, data to support these opinions are not available. |