Swimming is mainly the coordinated movement of the whole body muscles. A good swimmer has elastic muscles, well-proportioned figure and muscular arms: as long as he swims, he is exercising; Leg muscles: butterfly stroke, upturning, natural whipping up and down, only breaststroke is a pedal clip, so the focus of exercise is different. The former makes the legs longer, while the latter uses quadriceps femoris more, which is very effective in eliminating thigh fat; Chest muscle: The wave frog is similar to expanding the chest when rowing in. Although the butterfly stroke is the same, the upper body of the wave frog is higher in the water, and its movements are more stretched and the effect is the best. Shoulder muscles: breaststroke has the shortest stroke route and the exercise effect is slightly worse than others; Waist and hip muscles: the conversion range of wave frog's abdomen contraction and abdomen expansion is large, while other poses are flat and the conversion range is small, so frog pose is most suitable for reducing "general's belly"; Hip muscles: Hip muscles are basically relaxed when breast stroke bends hips and abdomen, but moderately tense when only lifting hips and sliding, especially when butterfly stroke bends hips less than wave frog, back and self, hips are basically kept tense all the time, which is more helpful to "lifting hips" and "little ass" than breast stroke.