The time spent in physical exercise is not lost. The student who is constantly poring over his books, while he takes but little exercise in the open air, does himself an injury. A proportionate exercise of the various organs and faculties of the body is essential to the best work of each. When the brain is constantly taxed, while the other organs are left inactive, there is a loss of physical and mental strength. The physical powers are robbed of their healthy tone, the mind loses its freshness and vigor, and a morbid excitability is the result.
(MYP 239.1)
In order for men and women to have well-balanced minds, all the powers of the being should be called into use and developed. There are in this world many who are one-sided because only one set of faculties has been cultivated, while others are dwarfed from inaction. The education of many youth is a failure. They overstudy, while they neglect that which pertains to the practical life. That the balance of the mind may be maintained, a judicious system of physical work should be combined with mental work, that there may be a harmonious development of all the powers.—Counsels to Parents, Teachers, and Students, 295-296.
(MYP 239.2)