Oh my gosh, I finally purchased mtn. bikes for my son and I today (GT avalanche 2.0's, one disc, one non-disc). He has never ridden a multi-speed bike before so we rode for a while when we got home. He did pretty well. Needless to say, after he was ready for a break, my testosterone kicked in and thinking I was 21 again instead of 37, I took off on my own (last time I biked consistently was probably when I was 21 or 22). I biked probably 3-4 miles at a pretty decent clip. Boy, am I out of shape! I knew I wasn't in the greatest shape but this is crazy. I've exercised my whole life until the last 3-4 years so I'm sure its just a matter of building up my endurance. I was looking at some nearby offroad options but I figure I better start with some regular riding before I jump off the deep end. Any advice? Thanks, Greg