I had a quadruple bypass in May of 2003 at age 48. A few months prior to that I had stopped riding due to chest pain. After surgery and rehab, I finally got back to riding some in about May of 2004. I now ride 100 miles a week or so and am getting ready for a couple of organized bike tours this summer. At my last visit with my cardiologist, I asked him if I should worry about "overdoing" it, for example, I rode 50+ miles the day before. He said no, that I could train for a marathon if I was so inclined, as long as I did it the "right" way, with proper diet, hydration, training regimen, etc. He also said that if I could ride a bike 50 miles, that I must be doing something right.

So, I guess I would say to follow your Doctor's advice and do whatever you feel is right for you.