I just try not to become a total slug in the winter. I amuse myself by : mountain biking when possible (it's warmer in the trees), xc skiing (when we have enough snow), running, swimming (indoors!), lifting (ugh), walking the dog, and doing yoga and pilates as needed. I drag out the trainer a couple-a times a week and find it's easier to do if I can gather up a few friends and a video. Drinking wine and reading good books still rank high on my list for "winter training" too and what about shovelling snow? That's gotta count for something, right?