I'm turning 40 next year, too!

The 2006 Danskin is the only tri I've done. Great fun. I want to do it every year.

What I've noticed with my longer biking rides is that I keep getting leaner and more flexible. I can sit crosslegged for hours. My posture is better, I think because my abs have gotten much stronger from the bike. (my abs were "cut" when I was kayaking 2-3 times a week last year, but they aren't that spiffy anymore!) I get fewer migraines. My knees and hips aren't as cranky.

And on the vanity side of things: I have lost 50 or 60 pounds, and my legs have some decent muscles!