As a student I used to do piecework on an arable farm in the Summer holidays. It involved driving tractors, walking up and down fields chopping the tops of bolting sugar beet, etc. It was fine and I never had any problems - just used insulin as needed for the amount of effort I was putting in.
I worked on farms for over 20 years as a qualified herdswoman, have also worked on pig/sheep/beef and arable farms.
Ran my own stud farm for about 16 years as well breeding Welsh cobs.
Type 1 for 50 years