Stand upright on a stair (or any slightly elevated surface). This is the starting position.
2. Slowly flex your ankle to lower your heels (This is the bottom of the rep).
3. Once your heel touched the ground (Or you felt you can’t flex your ankle anymore), raise your heel as much as you can by squeezing your calf (This is the top of the rep).
4. Constantly move your heel between these two points until fatique.
5. Once finished, Repeat the steps for the other calf.
Working muscle/muscles:
