120KG is really fat. First of all, there is a misunderstanding in your practice: you only do two sets of push-ups a day, which is really rare. You have to do at least four or more groups to be effective. The two groups just warm up, and the rest time between each group should not exceed one minute. The last few groups don't care about the number, even if they can't make 20, it doesn't matter, as long as they can't. The same is true of sit-ups. Do it in groups of three or four. If you feel unable to move, do sit-ups and leg lifts. This is to practice the lower abdominal muscles, and it is only complementary to sit-ups and upper abdominal muscles. Regarding dumbbells, I don't know what kind of exercise you do, but you can search the usage of dumbbells on Baidu, which is a lot. Which action to take depends on the individual situation. Do it in groups, too Increase the amount of each group and try to make each group exhausted. In addition, we should pay attention to rest, except for abdominal muscles, we can practice every day. It is best to practice other muscles every two or three days.