Swimming:didn't the summer, which movement have to be more economical than the swimming, to kill two birds with one stone again. The day was so hot, jumps is too crisp to the water in feeling. The material demonstrated that the water thermal conductivity is bigger than 26 times the air, if compared to the heat loss speeds up in the same temperature's water in the air 20 multiple, consumes person's quantity of heat effectively. The test indicated: If in the water middle reaches 100 meters, consumes 100 kilocalories heat energies, is equal runs 400 meters in the land, either rides the bicycle 1000 meters, either ice-skates 1500 meters. other ¡°as a result of the water wave's function, carries on the friction unceasingly to the human body epidermis, thus enables the skin to obtain the relaxation and the rest, therefore swims frequently the human, has a body brightly and cleanly, the soft skin¡±. ¡°hugs the grass to hit the rabbit¡±, the accident harvests.