I was in the Philippines for a month without a bike. Pretty hard to find a used bike there that would fit someone 6'3". So i went to the gym 3 to 4 times a week spending half the time on a stationary bike and half the time doing weight training. Not much different from my winter rkutine at home. Worked out fine. I dont compete, so im probably not as sensitive to missing a few days. But i do feel i retained my fitness well enough.