Exercise in education and medicine / by R. Tait McKenzie.

  • R. Tait McKenzie
Date:
1909
Catalogue details

Licence: Public Domain Mark

Credit: Exercise in education and medicine / by R. Tait McKenzie. Source: Wellcome Collection.

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    learns more easily through the eye than by translating a verbal command into a picture of the movement, while exercises by com¬ mand are much more exhausting to the attention of the pupil, but they have thus an additional educational value. This is the ques¬ tion upon which most of the wars between rival systems of gym¬ nastics have been fought. Exercises of endurance, which are simple, habitual, or even automatic, do not require great nervous concentration. A man can walk or run and have his mind on other things, but when they are carried to the point of acute fatigue, the phenomena of breathlessness, already described, takes place. If the exercise be continued after breathlessness has disappeared, the runner soon begins to notice a sensation of lassitude creeping over him, shown by an increasing lethargy and paralysis of the will power. His muscles become slower and slower in their response to his will; each effort requires a greater concentration of his attention. This lassitude gradually deepens; group after group of muscles refuse to perform their work, until he staggers along with relaxed grip, yielding ankle, fallen jaw, and drooping eye¬ lids—drunk with the poisons of fatigue. Repeated attacks of fatigue produce that chronic poisoning referred to in the last chapter as staleness or overtraining, which is, above all, a slow poisoning of the nervous system, just as sub¬ acute fatigue was a general intoxication by the products of mus¬ cle waste, and acute fatigue—an intoxication of the breathing apparatus. The role of passive exercise is one of relief to the nervous system, for the nutrition of muscles may be maintained without the expense of nervous force required to make them contract, and mas¬ sage acts on the central system through the nerves of sense, stimu¬ lating or soothing, according to the nature and amount of the manipulation. The absorption of carbohydrates and proteins by muscular action causes a hunger for food, just as the using of oxygen pro¬ duces a hunger for air. With the supply of food the muscles in¬ crease in size and strength, and the amount remaining unused is