HINTS FOR SWIMMERS

Evening Star, Issue 23094, 21 October 1938, Page 5

HINTS FOR SWIMMERS

MEDICAL MAN'S ADVICE WHAT RESEARCH STATISTICS SHOW The best temperature for swimming is about 18deg centigrade (64.4 deg Fahrenheit) or thereabouts. This was demonstrated from research statistics by Dr Fritz Duras (Director of Physical Education at Melbourne University) to a class of Sydney teachers recently. Experiments had shown, he said, that the loss of body weight in competitive swimming over a distance of 400 metres varied with water temperature as follows: 29deg centigrade ... 500 grammes 24deg centigrade ... 420 grammes 18deg centigrade ... 150 grammes 17deg centigrade ... 160 grammes 12deg centigrade ... 550 grammes 9deg centigrade ... 850 grammes “ The man who did this last swim must have been a hero,” Dr Duras remarked. The optimal temperature for this swimmer was l&deg (cent.). For competitive swimming the best temperature was probably between 17deg and 19deg centigrade (62.6 deg and 66.2 deg Fahrenheit). For ordinary swimming probably between 18deg and 21deg centigrade (64.4 deg and 69.8 deg Fahrenheit). Because of loss of body weight in the exercise, care should be_ taken with children in swimming, said Dr Duras. A child with a good fat layer was better protected than the thin child. EARS AND SWIMMING. Under-water swimming was not to be recommended for young children, said Dr Duras. Higher water pressure placed more strain on the heart. Blood pressure was increased, and the icturn of blood to the heart was not assisted by inspiration. The benefits of swimming were so great that it should be a regular school “subject.” Teaching was incomplete, however, without life saving instruction, especially for the older children. This has a high social and moral value in education. No pupil, should attend swimming lessons without medical examination. Dr Duras continued. This should particularly include examination of the ■ars. Many fatal swimming accidents were due to ear defects, and not to heart conditions, as was so often supposed. The inner ear contained the organ on which partly depended balance and the spatial sense. When water touched the inner ear on one side only and the eyes were closed, the sense of direction was disturbed. For children of the “ slender ” type it was advantageous to' train the skin by “ air bathing,” and the time passed in the water should be less than for “ stocky ” children. While _in the water children should keep moving, and they should rub themselves dry on leaving it; in warm weather, they should dress immediately. In German schools 10 rules governed swimming teaching, said Dr Duras. These were: (1) There must be medical examination before lessons; (2) only a physician could decide when and how often the child should swim; (3) the child must not enter the water when overheated', but cool the body first by showers or air bathing; (4) see - how /deep the water is before entering; (5) domt dive into shallow, unknown, or opaque water; (6) if unable to swim, a child must not enter deeper than to the lower part of the chest; (7) no swimming immediately after meals; (8) don’t stay in longer than five minutes when the water temperature is below 50deg Fahrenheit; (9) small children should not go into water under 6264deg; (10) in open water, sea, or stream don’t swim unless accompanied, and not in swampy water.

Energy consumption was greater in swimming than in any other sport. The intake of oxygen, which at rest was about 400 cubic centimetres per minute, in competitive middle-distance swimming might rise to 2,800 c.c. The resistance of the water _to the body was high, and varied with the swimmer’s speed—mathematically, according to the square of the speed. At twice a particular speed it was by comparison quadrupled. The crawl stroke gave the highest speed, because the swimmer’s movement was continuous. Hardening of the body depended on the “gymnastics of the skin vessels” (contraction and dilation). For this the strongest stimulation was that of alternate not and cold These should not be ordered for individuals under the age of 18-19. When ordered there might be a cold shower of one minute; later a hot one for up to half a minute; then a cold one for one minute, followed by a rub-down with the towel. This should only be commenced in the warm season.