Ａ 游泳之前一定要做好准备活动。因为人体皮肤的温度一般都比水温高，如不做准备活动就跳到水里去游泳，皮肤受冷水的刺激后，引起大脑皮质兴奋，使身体各部分肌肉产生强烈收缩，就容易发生抽筋、扭伤等事故，有人则会出现头晕、恶心等不良反应。做好准备活动再下水，可以改善 A swimming must be prepared before the event. Because the human skin temperature is generally higher than the water temperature, if not prepared to jump to the water to swim, the skin stimulated by cold water, causing the excitement of the cerebral cortex, so that various parts of the body muscles have a strong contraction, prone to cramps, Sprains and other accidents, some people will appear dizziness, nausea and other adverse reactions. Prepare for activities and then water, can be improved