Did you start doing it without warming up, or did you not exercise for a long time? Generally, in these two cases, after you finish all the actions of the abdominal ripper, you should lift your legs hard when you go upstairs, and wear pants with your hands! This is my personal experience. However, after three days, everything returned to normal. It is recommended to stop exercising or light exercise these days. You must pay attention to relaxing muscles after anaerobic exercise in the future, otherwise it will happen again.