Frequent stretching and relaxation of the joints and muscles of the limbs can lead to changes in the shape of the limb muscles, which means that the legs may become thinner. When the muscles are subjected to strong resistance to make them contract, there will be a slight rupture of the muscle cells, and the ruptured cells will gradually recover and heal to meet the needs of the limb strength, which will lead to the thickening and enlargement of the muscles at the same time, thus leading to the overall enlargement of the muscles. Stretching, relaxation and other yoga-like movements will make the muscle endurance stronger and the muscle extension better, thus achieving the role of correcting the muscle shape, that is, the role of correcting the body shape. However, it is necessary to ensure that the stretching is not carried out with large movements to avoid muscle damage, and proper stretching and relaxation will increase the blood circulation of the local muscles, making the overall muscles more soft and slender.