Nanci -
that's great! There are several studies that point out the beneficial effects of biking on running ability, and vice versa, so I'm not suprised at your success. I admit, I'm primarily a runner- competed in college- and found biking through the efforts of my bf (yes, the one that tangled with the SUV) and through triathlons. I doubt it will ever supplant running for me, barring injury like yours, but the appeal to the "long distance runner/biker" is exactly the same, imho. Your CV system doesn't know the difference, and the only real change is the lack of impact- which can be both good and bad. Congrats on your progress, and maybe, just maybe, I'll have to follow your lead and switch out some of my long runs for long rides!