I did it this past Sunday. I had been training on a mostly flat path with a few short, low grade hills. I have been nursing a sore achille on my left foot for about 3 months now, so I tried to be reasonable and took 2-3 days off between long rides. In the few weeks before the event, I would ride a minimum of 30km, with a 45 to 60km ride once a week.
The ride for heart took place on the Don Valley Parkway, which is the main highway through the core of Toronto. I had totally underestimated just how hilly it is. In fact, it seems to be just about all that, one long hill after another. About 13,000 participants showed up. To my amazement, I’m sure I passed hundreds of cyclists going up hills during the course of the event. I was more worried about the descents, however if anything that ride gave me tons of time to get better and more comfortable going down them. All went well and I felt pretty good until I had about 50km or so behind me. By the time I reached over 60km, my knees and thighs were hurting real good, but I pushed fwd anyway.
I got much satisfaction out of doing this. It is nothing compared to what some of you have accomplished, but it seems not so long ago I was trying to unicycle 30m without falling off - lol.