You know, donrhummy has an interesting point. Maybe you'd be interested in building speed... Just as in foot racing, you've got sprinters and marathonners.

I have a work friend who lives in Europe now, but when he was here, we were known as Fast & Far. He was Fast, I was Far. Ben was good for maybe an hour & a half, but he'd average 20 - 22mph for the ride... dang near serious amateur territory. Me, on the other hand... As my screen name implies, I tend to plod. My best ever century was 6:07:20 at 16.6mph... somewhat off of the TdF group average of right around 4:00:00.

So there, you could build up to Far, or you could work on Fast. Either way, you're on a bike, and that's better than anything else I can think of.

BTW, cancer was of the rectal (Or Butt Rot, as I like to call it) variety... Just the thing to make perching on a skinny bike saddle all day that much more comfy. I'm pretty sure my fitness level saved my life. Also, I figure if that buzz-cut kid from Texas... Lance-something-or-other... can make the best of it, well, I can too. Tell ya this: After what I've seen, ain't a thing out there on the road gonna scare me at all.