Originally Posted by srode1

Curious how fit you were before the back problems? That will have a big impact on how fast you can get back to shape for a double. I'd just start with 1 hour rides at an endurance pace to see how much you can tolerate, then start going longer, then a couple blocks of Temp intervals, then Steady State, then adding long rides on weekends to the Steady State intervals, so you have a long ride right after your intervals. Long ride work up to 4 hours or so.