In the summer I usually swim quiet a bit, and go out running too, and it seems to help quite a bit in developing my lung capacity, since that seems to be the area that I struggle with, rather than the leg strength. I also do core exercises, sit-ups, the plank, a lot of static movements to develop my lower back and stomach since it seems to help a lot when I go out for really long stretches of cycling. Do you do anything else than cycling and how does it relate or improve your ability to cycle? Does going to the gym help any of you?