Exercise IS necessary, however you do not want to do anything too drastic or too soon. Having triplets will definitely stretch that skin!!!
If your doctor allows it, you can do light cardio and/or brisk walking/treadmill 2-3 weeks post op, depending on the severity of the tuck. Hold off on weight training until 5-6 weeks post op. Wait at least 7-8 weeks for sit ups/crunches. You dont want to develop a seroma! Consult with your surgeon for individually based clarification.
Applying a topical to minimize scar appearance depends on several factors. Did you take appropriate supplements prior to your surgery? Did you apply olive oil or cocoa butter prior to surgery? Are you taking supplements currently? What topical did your surgeon suggest you apply? Mederma? These factors are all crucial.
Regardless of your surgeon's size or beliefs, exercise is necessary for everyone!!!
If many people exercised the PS industry would not be able to perform many procedures.