Most Saturday mornings, I bicycle with a group of men, mostly in their 50s, whom I affectionately call the Cheat Death group. We are all in pretty good shape, competitive but supportive, and convinced that hard-core exercise is our ticket to postponing the inevitable.

The ride a few Saturdays back was a tough one. At 6:30 a.m., the pack took off fast and immediately headed for the hills near Durham, N.H. The first few climbs felt pretty good, but by the third hill I started to feel nauseated.

Figuring that was probably a result of the four beers and large Chinese dinner the night before, I kept going. Twenty-five miles into the ride, I had fallen to the back of the pack. I was short of breath and wondering how I was going to make it much farther.

I am someone who hates to quit. But after the third time the group had to stop and wait for me, I decided I had no choice. I watched them pedal away, then lay down in the grass.