Bend your thighs and calves 90 degrees on the stool, then tighten your feet so that you can relax after a while and repeat the previous actions. Also, you can go up two floors when you go up the stairs.

1. Sit in a chair, hold both sides of the chair with both hands, fix your body, lift one foot and straighten your knees for 30 seconds.

2. Then do the same action with the other foot. It should be noted that the position of the knee should not move while straightening the knee. ?

3. (Left) Sit in a chair, hold both sides of the chair with both hands, fix your body, lift one foot and straighten your knees for 30 seconds. Then do the same thing with the other foot. It should be noted that the position of the knee should not move while straightening the knee.

4. (Right) Sit in a chair, hold your chest out, cross your legs, and land on your toes. Push down the thighs and push up the calves. After about 10 second, do the same thing 10 second, 2-3 times. You don't have to hold your breath to do this action.