If you're serious, don't take much time off, for each day you take off after your recovery period you'll need a week of training to get back to the same level.
It may be wise to find a way alternative way to train so you won't get stale- nordic skiing, skating etc. You should definitely weight train to strengthen your upper body. You should also work on your hamstrings,(leg curls), and inner quad heads,(concentrate on the last 10 degrees of leg extentions). Your hamstring strength to quadricep strength ratio should be at least 2 to 3. Riding heavily tends to over-develop the outer quadrecep muscle, which will eventually pull the kneecap off track and cause quandramalasia, spelling?, it is very painful and when you notice it, it is too late. The doctors like to cut your outer quad attachment at the knee to fix it. Plyometric exercises are good to develop your sprint and snap. Perhaps most important, work on your flexiblity, you'll spin faster and have less injuries, a martial art or modern dance class really helps.
[Edited by pat5319 on Jan 5th at 12:58 AM]