Thus, as to the vital or nutritive system, exercises taken when digestion is not going on, excite the digestive faculty: taken during its progress, they disorder that function. The arterial and venous circulations become more rapid by active exercise, which concludes by giving greater force to the tissue of the heart. It is the same with respiration and calorification. The same takes place with regard to nutrition, a function which exercise increases, not only in the muscles in movement, as we have just seen, but also in the bones, ligaments, vessels, and nerves. By inducing cutaneous exhalation, it promotes the expulsion of injurious agents, produces a fresh colour in persons who may have become pale through a sedentary life, and, to a certain extent, renders the human constitution, by means of habit, proof against the action of surrounding objects. The local effects of excessive action, or those which take place in the members themselves, are, as before observed, inflammation of the muscles, rheumatism, like that arising from cold, and inflammation of the serous articular membranes. The general effects of excessive exercise may, in the same manner as all physical and moral stimulants, exhaust the vital faculties too quickly, communicate too much rigidity to the fibres, render the vessels varicose, bring on chronic rheumatism, destroy the freshness of the skin, blight the flower of youth, and produce old age and death before the time ordained by nature. Ancient writers inform us that it was a rare thing to meet with athletes, who, having signalized themselves from their earliest youth in gymnastic combats, were of so excellent a constitution as to be able, when they had reached a more advanced age, to acquire the same honours on contending for the prize with grown men. Aristotle assures us, that amongst the conquerors in the Olympic Games, not more than two or three at the most could be found to whom nature had granted such an advantage.