No one will dispute the general principle that exercise is essential to the well being of the human organism. Lack of use of a part or structure adapted to energetic functioning is likely to lead to poor nutrition and perhaps even to atrophy of the organ concerned. The phenomena of overexertion are not so generally recognized, although it would not be difficult for any physician to recall instances of damage thereby, particularly in relation to the circulatory apparatus. In other words, both overexertion and disuse of vital organs represent extremes of undesirable personal behavior. Perfect health demands a performance that shall steer a safe course between deficient exercise and undue effort.
The foregoing comments have an added import in connection with the problem of athletic sports. So long as these are in sole charge of untrained "trainers" there will be an element of danger in the win-at-all-costs attitude that is
INDICATIONS OF PHYSICAL OVEREXERTION. JAMA. 1918;71(18):1488. doi:10.1001/jama.1918.02600440040013