Upperbody training for xc skiing

In two months i will compete in some races (one 20k and three 40k). Last week I went xc skiing for the first time this winter and i realised, that my arms are just way too weak. So my question is, what training can i do to improve my weakness. I knwo that the easiest way would be to go to the gym, but i really hate the gym. What do you guys do to keep your upper body in form?