Swimming will be more efficient than running to lose weight, because swimming is in a state of buoyancy of the whole body in the water, which will cause weightlessness to the body, plus the water temperature, if low will release a lot of heat in the body, muscle heat production, the water inside the pool is cool, it will cause a state of low temperature, can absorb more heat from the body. Compared to running, swimming is less damage to the joints, mainly because of the role of water buoyancy, from the consumption of fat is also swimming is better, swimming on the whole body fat consumption is more balanced. In terms of exercise, swimming is a better exercise, running requires a venue, the wear and tear on the joints is also relatively large, swimming will be better.