The goal for off-season is to stay fit but not work too hard at it! Your body and head need to recharge; any physical problems you’ve dealt with in-season need to be resolved before you ramp up next spring.
Some of us who ‘can’t kick the habit’ still need/want to do some training every day even though race season is months away, and that’s OK. Skip most or all of your intensity work for a few months. Put in less time. Base fitness will not drop off much if you stay consistent. Attempting to maintain peak fitness through the off-season is not realistic and unwise. For those athletes who need complete time off I recommend not going for more than 1-2 weeks without training.
Reflect on your race season; what could have been better; what can you do to improve going forward? Perhaps you need some time in the gym for core and weight work. Hit a scale every once in a while to keep it real.
Off-season is time to improve form in each discipline so you can focus 100% on the aerobic training come spring when you should be ramping it up; putting-in the S/B/R time without other distractions.
Add some variety to your off-season training to keep it interesting. Pedaling is pedaling when you don’t need to be tuned to a race specific bike. When it gets cold and ugly on the trails and roads I’ll be on my mountain bike (on pavement) more than on the road bike. I go slower on the MTB, so don’t get as cold, and my road bike doesn’t get trashed on messy roads.
Most athletes will be weather and/or darkness limited on at least on weekdays and so will need to do some workouts indoors. Indoor ‘dreadmill’ runs are better than no run; jumping into a spin class to get the heart rate up a bit is better than no ride. Solo on a spin bike at the gym, no problem, there might be some ‘visual vitamins’ to keep you pedaling! Stationary bikes at home with music, video, Computrainer entertainment, maybe even rollers. It’s all good!
Cross train: your aerobic system doesn’t know the difference between a swim, pedaling session, a run, even an XC-ski day. Cross country skate ski is a Colorado favorite, engaging upper body muscles as well as abductors and adductors that don’t see much work for S/B/R.
Whole body muscular fitness developed during off-season leaves you more balanced and less susceptible to injury in-season. Race season should be more aerobic workout time focused, but all endurance athletes should do some core work year-round.
And of course I recommend hiring a coach to make your off-season productive! =)