Two freehand abdominal muscle exercises
1. Lie flat on your back, put your feet tightly together, and lift them 10 centimeters. Keep this action for about 10 seconds, then put your feet down. Repeat this set of actions 50 times. If you do it 100 times, the effect will be more ideal.
2. Lie flat on your back, put your feet together, bend your knees, cross your hands behind your head, rotate your neck, face up, lift your head slightly upward, look toward your knees, head upward. Exercise 50-100 times.
