Q1自由泳时身体要保持一定的紧张度,要挺直胸背、收腹等,感觉走水比较好,但是坚持不了多一会,很累人,是我紧张过度了还是不习惯呢?Q2我的右侧换气老喝水,感觉这时腰还有点塌、左手有点撑不住要下压,是不是除了加强弱侧的划水时效外,还应该把腰挺直?Q3很多教学视频都说髋部是发动机,打腿可以帮助驱动转髋,转髋又可以帮助划水。这可能不适用于专业运动员,因 Q1 freestyle when the body to maintain a certain degree of tension, to straighten the chest back, abdomen, etc., feel better to go the water, but can not stand for a while, it is tiring, is I nervous or not used to it? Q2 I The old side of the ventilation of the old water, feel the waist still a bit collapsed, a little left to hold down the pressure, is not in addition to strengthening the weak side of the paddock aging, but also the waist should be straight? Q3 a lot of teaching videos That the hip is the engine, legs can help turn hips, turn hips can help paddling. This may not be suitable for professional athletes because