I'm 6'3", 225 lbs and riddled with basketball injuries including bad knees and ankles. I think road running is boring and, at my size, counterproductive. Treadmills are the most perverse human creations ever. That said, I'm a firm believer in cross training and I know from experience that running has its benefits.

My solution is trail running. I run technical singletrack and fireroads at least once a week, sometimes 3-4 times a week if I'm bored of riding or my bike is in the shop. It's infinitely more fun than riding on the road, especially the singletrack, and it is much easier on your body once you develop your technique. Running a scenic fire road at night with a Petzl and an mp3 player rivals a good road ride. And the best thing is that my trail running shoes cost me $40. Who can beat that?

Cycling has been my main activity for the last eight or nine years and I love it to death but cyclists that shun running, lifting or other sports, especially in the off season, seem to subscribe to a one-dimensional view of fitness.