I try to keep in shape year round, although there have been two times during those 21 years (3 months in 2001, and several months in mid-2009) where health issues have caused me to lose my fitness.

I've been cycling regularly for 21 years now, and have combined that with other activities such as spinning classes, weightlifting, snowshoeing, cross-country skiing, swimming, canoeing, hiking, and lots and lots of walking.

If you can, join a spinning class ... a good one will whip you into shape!! And as soon as you can get outside, ride regularly 4-6 days a week. I'd also recommend doing some upper body work which can be very beneficial when riding longer distances and for other aspects of touring. How much and how often are you riding the trainer now?