I play squash 3-4times a week, for the last 4-5months, and I find the constant stretching and explosive sprinting is helping my riding no end! Obviously the general fitness that will come with it, will help too.
But, I've noticed when I HAVE to get out of the saddle, the leg burn takes a noticeably longer time to kick in. Moving my weight around the bike feels easier, and more nimble too.