In no field of physiology has there been, within recent years, more rapid growth than in the field of the physiology of exercise. So rapid has been this progress that the results of the studies pursued in the various research laboratories, both in America and in various European countries, have appeared in many of the world's scientific journals, some of which are difficultly accessible to the lay reader.
In this volume we have attempted to present to the reader for the first time a digested compilation of the principle facts made available through these many studies. So far as is possible, the language employed. in this volume has been non-technical with the purpose in view that this volume may serve not only as a textbook for students of physical education, and as a reference book for advanced students and teachers of physiology, but also as leisure reading for physicians and others who may be interested in the effects of exercise on the normal growth and physical development of the human body.
The subject matter presented in this book is strictly physiological in nature. The human body is considered as a super-machine with variable capacities and limitations as a result of an equally variable physical inheritance, development, and training. The mere compilation of facts or the presentation of miscellaneous theories has been considered of secondary importance to the logical organization of this fund of information in such a manner as to offer a satisfactory explanation of the physiologic and mechanical factors involved in bodily movements and the performance of work. The subject matter has been selected and presented with this aim in mind.
Where the experimental evidence has been controversial, we have attempted to justly state the two sides of the problem and let the test of time and further research decide the issue, or in a few instances we have tinged the controversy with personal opinions. If we have been remiss in overlooking any important studies, it is only through error of the flesh and such omissions, where pertinent to the general purpose of this volume, are regrettable.
It is impossible to single out at this time the entire list of names to whom we owe our grateful thanks for the studies which have made this volume possible. Credit has been duly given throughout the text and at the end of each chapter. We would be remiss, however, if we did not at this time extend our thanks to our colleagues who have aided us by their advice and encouragement, to Miss Edna Maughan for her artistic aid in many of the illustrations, and to A. S. Barnes and Company for their patience and diligence in the publication of this work.
A. G. GOULD, J. A. DYE.