After a tummy tuck with muscle tightening, the muscles should be as tight and flat as possible and do not really need to be worked hard to keep them that way (such as with sit-ups or crunches). In fact, in my opinion, too vigorous excercise, especially in the early healing period, could do more harm than good.That being said, I have seen a couple of patients who relied so heavily on their compression garment to hold everything in that the muscles actually got lazy, lost tone, and let the belly pooch out.Due to that, I will sometimes recommend for patients to do isometric excersises such as holding the muscles tight and/or sucking the stomach in to help keep up the muscle tone. In general, after a tummy tuck, I believe core strengthening excercises that work the muscles without vigorous activity, such as yoga and planks, are better than other more active excercises such as sit-ups.Thank you.