Hook your feet to the front tube, put your hands behind your head and do sit-ups to exercise your abdominal muscles.

Sit-ups (mainly exercise six-pack abdominal muscles and quickly consume abdominal fat)

Back contraction exercise (mainly exercises muscles related to the back and is also the main method to relieve lumbar muscle strain)

Usage of supine leg lifting (mainly abdominal webbed exercise):

Lie flat on a healthy net.