As far as I'm aware, insulin resistance for many people is caused by free fatty acids depositing fat around the internal organs, and the only way of getting rid of it is to lose most of the excess body fat, which will then trigger the body to burn off the internal organ fat. That's why the first thing they suggest is to lose weight, because it will help any meds to act more efficiently and take some strain off the pancreas. That applies to any of us, whether T1, T2 or non-diabetic. The only difference is that non-D's don't get to find out.
My weight has gone down a bit but my insulin requirements are currently going up, presumably due to sitting on my bum more instead of working outside. I really need to exercise more to burn off some of that internal fat.
Exercise also helps by speeding up the metabolism, which helps to burn off fat quicker and increase blood flow which will improve overall health, especially when at risk from neuropathy and other complications.
Rob