I am 35, just started road riding this summer. I plan to start racing next year. My 29yo brother started road riding 1 1/2 years ago and he was racing cat3 at the end of this season. I've been watching him race and I want to have some fun too. I would like to chase him in some crits next season, so I am powering up through the winter. I'm not sure that I will be in Cat 3 next year, but maybe the year after that. I go on rides with him and he kills me. It is all great fun though.

Train with people faster than you: experiment with a lot of different group rides. I have learned a lot by doing group rides. It has helped me get used to riding at close quarters, and to learn to pace myself and to push myself. If I ride too hard early and get dropped or fall off the back I consider it a victory - in an educational sense, and also because I know that I am asking my body to get stronger. I love the excitment and challenge of a fast group ride; I am sad when I miss one.

Your current mileage and riding sounds a lot like my own. Perhaps one difference is that I have generally maintained a level of fitness from running and mountain biking (on and off) over the years. So I had somewhat of an endurance base at the time I took up road riding. I have no fear about jumping into Cat 5. From the races that I watched and talking to my brother and some other riders I expect no problems getting into Cat 4 next season and it sounds like you could do the same if you go for it.

Good luck.