I've done a grand total of 2! Both were done this year....Didn't really prepare for either, just rode my bike leading up the centuries. The first one was actually decided on the week or two before. My wife and I had intended on doing the metric, since it was our first major ride of the season, but got talked into doing the full blown century. That one hurt both us of because of the heat in Georgia. It was May, coming from Ontario, we were not accustomed to the hot and humid weather. It took a good bit to recover from that ride. The second one was better. It was in north Toronto and in September so it was cool, but really wet. We finished that one with gas left in the tank. Even though I felt good at the end it still took a bit to recover from that ride too.

Next year we hope to do another couple, but we'll see if we can manage more. I don't see us doing anything longer then that though since the recovery periods are long enough.

Personally we just like getting out on a Saturday morning and doing 100-130km and calling it a day. We get home just after noon, stretch, eat, get cleaned up and then head out for a coffee and the rest of the day.