Hi Martin,
The usual school of thought is carbs to supply you body with fuel to give you energy to exercise before and protein afterwards to feed your muscles and promote growth.
Is that going to be ok for you how do you handle carbs?
If you on a Keto or LCFH diet then your body should handle burning fat instead of carbs for energy.
Have you tried lowering insulin before/after exercise, rather than eating carbs? My DSN suggested this and, through trial and error, I found what worked for me on MDI. The pump has made exercise even easier ( I don't mean that literally!).