I will choose skipping rope. Such a cheap tool is necessary for dieters. The key is convenience, find a place where no one is (not in the dormitory, otherwise you know, haha). Generally, I will insist on jumping about 300 times, regardless of speed, and slow down when I am tired. At first, I felt sore all over the next day, and then I paid attention to relaxing, which was much better. If you relax, it's actually similar to the relaxation movements on the physical education class, mainly leg press, relaxing the calf and so on. There is also a good action, two toes touch the wall, one knee touches the wall, the other leg is straight, both hands hold the wall, lean forward against the wall and keep the lower body still, you will feel a pulling feeling on the calf muscles of the straight leg, especially the heel.