Editorial Physical Fitness and Cardiovascular Health

and physical fitness have been discussed at several recent symposia, bringing together physical therapists, physical educators, nu-tritionists, exercise physiologists, epidemi-ologists, practicing physicians, and other disciplines of the health profession. Most workers close to the field of physical fitness feel that it is a good thing to have; yet most will admit (at least secretly) that absolute proof of this fundamental point is still lacking. This report is intended to survey some of the cur-rent knowledge and problems in fitness re-search, much of which was revieved at a recent symposium in Toronto.' Physical fitness still defies exact definition or measurement, partly because fitness is a multifaceted qualitative parameter that is usually specific to the task involved, and the scores of the many different tests available to measure fitness are not closely correlated.2 To escape this dilemma, there is a tendency to oversimplify the situation by considering a supposedly definable parameter (aerobic power, maximal oxygen uptake [Vo2 max]) as the best single measure of overall fitness. During exercise, cardiac output levels off be-fore V02 max is reached3; pulmonary ven-tilation, diffusion, and the capacity of the respiratory muscles have approached maximal values; and the exercising muscles are almost fully taxed. Although in normal subjects the exact factor limiting maximal oxygen uptake is unknown, a disorder of the cardiac, res-piratory, or musculoskeletal systems usually results in the involved system becoming the limiting function. Vo, max is closely corre-lated with heart volume, vital capacity, total body hemoglobin, lean body weight, an