If you use a smart phone, you can do some abdominal slimming exercise software. Exercise for at least 45 minutes every day and do abdominal exercises for at least 15 minutes. For example, in Duoyan Zheng, there is a set of calisthenics that sit on the ground and do push-ups at no cost. You can spread a blanket in the living room. There is also free time to soak your feet every day and a 20-minute slimming package.
Sit-ups are good, but they are hard to stick to. Don't believe in hula hoops and things like that.