Frankly speaking, I don't know, but as a fitness enthusiast, I have learned from six years of intermittent exercise: exercise yourself and let others talk! Read more books about fitness by yourself. A reasonable diet can make your figure out of shape within one month, but it takes three months to get a piece. According to your physical condition. You can do push-ups and sit-ups at home, you must have a plan, and the most important thing is to stick to it! It's really hard to persist. It's up to you. I also want to add that abdominal muscles are the most difficult to practice and the most difficult to maintain. You have worked hard for a summer, but if you don't exercise as planned in a winter, your abdominal muscles will be gone.