I've been there, or close enough, and am still recovering. As Maddmaxx suggested, you will probably need another form of exercise. He said "especially in winter." This is dependent on where you live of course, here in Florida winter is prime time for biking (most days anyway) and summer is when you tend to hybernate. I have a Nordic Track that is good exercise, it works well set up in front of a TV and under a ceiling fan. It is low impact and I dislike it enough that it gives me motivation to go get on the bike even if it is cold, hot, windy, etc. etc. etc. when that is my option :-)