４２、The following appeared in the editorial section of a health and fitness magazine. "In a study of the effects of exercise on longevity, medical researchers tracked 500 middle-aged men over a 20-year period. The subjects represented a variety of occupations in several different parts of the country and responded to an annual survey in which they were asked: How often and how strenuously do you exercise? Of those who responded, the men who reported that they engaged in vigorous outdoor exercise nearly every day lived longer than the men who reported that they exercised mildly only once or twice a week. Given the clear link that this study establishes between longevity and exercise, doctors should not recommend moderate exercise to their patients but should instead encourage vigorous outdoor exercise on a daily basis."