Special treatment of gymnastics, athletics and mental hygiene is given under separate articles. Only general aspects of the subject are discussed here.
The importance of physical education in relation to health has been emphasized in recent years in a twofold way: first, because of its significance for the normal development of children and the maintenance of general physical health; second, because of its significance for mental health. The minimum amount of physical exercise for the maintenance and development of physical health has been suggested by Hetherington as follows: Four hours of muscular activity at the age of 5 years, five hours from the age cf 7 to 9, six hours from 9 to I I, five hours from I I to 13, four hours from 13 to 16, three hours from 16 to 18, and two hours daily from 18 to 20.
The slogan of physical education from the days of the Greeks until the present has been m.ens sang in corpore sane, the sound mind in the sound body, with the implication that the sound body is a condition of mental sanity. In modern times, under the in fluence of the great teachers of physical training in Europe, Guts, Muths, Jahn and others in Germany, Ling and the founders of Swedish gymnastics, the training has naturally centred much more upon physical education. While the mental factor in this
twofold aim has often been neglected, in recent times the emphasis has been placed largely on the mental aspects of physical training. In a report of a special committee to the Society of Directors of Physical Education in Colleges made in 1921 the committee emphasized right mental attitudes, self-sacrifice, loyalty and co operation, and mentioned some of the more generic of these mental attitudes as their first group of aims. Thus to-day there is growing the theory that physical education affords opportunity for im portant training in mental hygiene as well as for physical health. While we do not go as far as Plato and say that God gave men music and gymnastics for mental culture alone, we do now empha size the development of healthy mental attitudes and interests as the culminating value of such training.
With the development of physical education in relation to somatic and mental health, it has become a subject for scientific research as well as a practical art, as indicated by recent litera ture. In the practice of hygiene the best schools to-day supple ment instruction by actual training in health habits; and in the colleges the highest ideal is the acquisition of health intelligence as demonstrated by health habits. (See also PHYSICAL CULTURE, and for English legislation on the subject see EDUCA TION.)