A consequence of the fitness boom has been that it is now commonplace for symptomless people to go to their physicians to be checked out before they take up jogging, racquetball, or aerobic dancing. What most people are concerned about is the presence of coronary arterial disease and the possibility that the exercise will cause sudden death or myocardial infarction. The public, persuaded that such checkups are as crudely mechanistic as those for automobiles, is happy to pay physicians to carry them out, although there is little evidence that such routine checks effectively reduce morbidity or mortality from subsequent exercise.
Increasing affluence and a greater interest in the outdoors have caused ever larger numbers of people to go to the mountains to exercise—either to climb, walk (trek), or ski cross-country. (Downhill skiing, where the work is done by the lift, is not an impressive aerobic challenge.) Many of these people