Why? The Science of Athletics

HEAT, LIGHT AND ENERGY 339 hot an atmosphere the blood heat escapes by the skin, or, if it is very hot, or we make ourselves very hot by violent exercise, the sweat-glands get their orders from the nerve– centres and sweating is induced, so that the heat is extracted from the blood. This mechanism suffices if the air is dry. The effect of climatic change provides one Climatic of those problems which are always confront- Change and ing the coach. He may have trained his boys Acclimatization through a hot spell and suddenly find him- self up against a cold· snap on the actual day of competition. What is he to do with his field events men ? The runners will have to strip out, anyway ; with the throwing men it is no great matter, for a man will probably throw just as well in a loose sweater and a pair of track trousers as he will if properly stripped for action. But .with the high jumpers and pole vaulters the case is different. At first sight, the obvious thing to do seems to be to tell them to discard their outer clothing piece by piece as the bar rises, and that is what is often done ; but it is not altogether a wise ' policy, perhaps not so wise as letting a man jump right through in his whole sweat-suit, or, at any rate, in his sweater, because every ounce of weight, whether added or taken away, makes a difference to the disposition of a -man's jumping balance, and that it just · the thing that counts in these events. And, again, it may well be that the danger of the slack of the outer garments removing the cross-bar constitutes too big a risk to be entertained. In such circumstances I get my boys either to put on a couple of vests, or to wear a light but close– fitting sweater over the singlet and a loose thick sweater with a high neck on top of that, for the time they are waiting to take their turns. . I have not yet, however, been able to persuade any of them to wear closely fitting trunks on cold day; although that is obviously the logical procedure, which has been adopted by numerous Continental jumpers. ' ' I ,, ~ •I pi ! ~ ~~ ~I i J. !