In his constant exploration of the benefits of physical culture—the sporting culture of exercise which did not exist in France during his youth—Baron Pierre de Coubertin explored the depths of human motivation.  He read widely, collaborated with medical professionals and exercise theorists and described what he observed as the response of the human body to the challenges of sport and exercise.  This quote, from an essay on The Philosophy of Physical Culture, which appeared in the Olympic Review in May 1909, is one of many examples of the theories he developed over the course of his career.  Like so many of his ideas, this theory has proven true.  Athletes with the will to push themselves in daring ways with great consistency are still succeeding a century later. 

“Many moral and intellectual forces work in harmony to improve the human body.… Doubtless, the will and its adjuncts, daring and perseverance, form a trinity that is unequaled in its power to generate improvement. Yet we can make significant progress as well by observing, in ourselves and in others, the effects of physical exercise, and by knowing how to reflect on those effects methodically and productively.”