It was the Roman poet Juvenal who coined the illustrious Latin phrase, mens sana in corpore sano, and bequeathed to the world the enduring axiom of a healthy mind in a healthy body.  As he considered the phrase in the Olympic context, Baron Pierre de Coubertin thought it fell short of the achievements of the athletes he admired. So he recast it to add the idea of intellectual fervor and physical training to the basic formula.  Here is an excerpt from the Olympic Review of July 1911 in which the Baron discusses the slightly revised formulation of mens fervida in corpore lacertoso: 

“Mens fervida in corpore lacertoso. ‘An ardent mind in a well-trained body.’ The Revue Olympique debated the value of the motto ... an eminent Latinist and member of the IOC was not fully satisfied with the use of the word lacertosus. Later on, Pope Pius XI expressed concern about the ideal fervidus. In both instances, the notion of excess was replacing the notion of balance. That is what its originator intended; his principles on this matter are well known. The modern educational system was creating a bold definition of itself: an ardent soul, a trained body, exuberance of the mind opposed to the exuberance of the muscles, or rather complementing it. This is the educational perspective of aviators, risk-takers, and the like.”