Over-doing is a term that refers to doing something excessively. It can be applied to various situations, from work to exercise and even eating. There are several antonyms to the word over-doing, which can be used in different contexts. One of the antonyms is moderation, which refers to doing something in a balanced and reasonable way. Another antonym is restraint, which means to hold back or restrict oneself from doing something too much. Other antonyms for over-doing include under-doing, inactivity, and relaxation. It's essential to find the right balance between over-doing and under-doing activities, activities that can be done in moderation or with restraint.