But remember, if you want to lose belly fat, no matter what aerobic exercise you do, you'd better do some sit-ups. Also do the action of lying flat and lifting legs, which is also abdominal exercise. Specifically, lie flat with your hands on your sides. Keep your legs straight, lift them at a 90-degree angle, and then slowly lower them. Try to keep your legs straight in the meantime. After you put them down, lift them slowly (remember not to touch the ground when you put them down) to avoid repeated fatigue.