You can stand up straight in class, sit on tiptoe for a while, and massage with your hands, grab your calves from top to bottom, and knead each leg with your thumb every day 15 minutes.

30 push-ups and 50 sit-ups before going to bed every night. Improve metabolism and exercise chest and abdominal muscles after sleeping. Now I must stand up and have a rest between classes, so that the blood in my legs can have a good circulation. This is what I do every day. Abdominal muscles are a little obvious.