Why? The Science of Athletics

CONSIDERATIONS IN RELATION TO COMPETITION 141 part of his general reserve. But when he passes point P (Fig. I4) and his running begins to decrease he uses up a further portion as shown by the bracket y in column E (Fig. I5), and of that extra portion the part shown by the bracket z is drawn from the heart's reserve. This is where Dr. Martin's ingenious explanation of the phenomenon of second wind comes in. The heart works on its own reserve in order that it may overcome the resistance of the partly intoxicated muscles, and it is during this time that temporary acidosis is neutralized by , means of the "buffer" alkaline substances in the blood. Rapid recuperation of the nervous reserve ensues simul– taneously as the temporary acidosis, met by the heart mechanically and the blood chemically, stimulates the nerve centres to increased activity, thus renewing the runner's vitality by giving him his "second wind". In this way the trained athlete running on his reserve gives his normal energy a chance to recuperate, whereas the untrained or insufficiently trained man forces his heart to use its own reserve, and there is a very vast difference between the two sets of circumstances. Thus, in the phenomenon of second wind you have involved the natural potential of the heart, the general nervous potential, and the chemical reaction of the blood. When a man uses up a part of his heart energy he recuperates very quickly and, having broken up the first resistance, can work on his nerves, although he will have no more resistance in the muscles-. In addition, it must be remember~d that the blood supply is increased by the action of the heart, and, the second wind having appeared, no second intoxication will follow. From what has been said it seems fair to assume that if the athlete's blood could be immediately examined when he reached point P in Fig. I4, his fatigue-point, it would be acid, whereas from point P to the finish of the race it would be becoming more alkaline during the time he was running on his second wind. · Systematic training and scientific feeding, it would