I right now promise not to ever feel sorry for myself after reading your OP. Congrats on beating cancer, your times and speed rate are not bad at all, mine are almost identical but, I am not getting over cancer surgery and radiation treatments. Size wise we are similar, I'm 6'-1", 230lbs, down from 278 last year and dropping. My mother had them following colon cancer, 2X day, 7 days a week, 6 weeks and it damn near killed her. You have nothing to be hanging your head about.

JYL and Chasm probably had the best summary of what you might try doing, I'll suggest you get Joe Friel's book, "The Cyclist Training Bible" http://www.amazon.com/Cyclists-Train...ords=joe+friel and maybe a few other books he has written. I really like the Cyclist/Bible tome a lot.

Best wishes on your training and riding Hobkirk, you are one of the members here that encourage and inspire me.

Bill