Wow! Thanks OB1 that's a lot of info to digest at one sitting.

I am 43 years old and ride only on the road right now. I was a decent athlete in high school running track and playing football. I have done some athletic type stuff through the years so I don't know if I would classify myself as a couch potato.....although I could stand to be in much better shape. I'm not overweight(5'10" 160lbs) in my opinion and never have been. Just started riding last year and feel MUCH MUCH stronger now than I did when I started. A couple of hills that used to kick my butt every time I tried them are now a piece of cake. Now I just stand on the pedals and fly up them in a middle gear as fast as I can. Hiils were torture a few months ago, now they are FUN FUN FUN!
I'm not in it to win any races, or even ENTER any races for that matter. I just want to have fun riding but at the same time I want to be able to increase my strength and stamina along the way. I have plenty of days for those "easy" rides.....those would be the days my wife rides along...hahaha.

Seems like I only feel "weak" on days when I go out and ride two days in a row and really "push it". Even if I rest for two days after that I sometimes just feel plain lousy the next day I ride. I think I better stick to maybe one or two "hard" rides a week, followed by an easy day and then one rest day after the easy day(or some combination close to that). Maybe that would help flush out the bad stuff and give the old muscles a chance to renew. Thanks again!!