Originally Posted by bhtooefr
2manybikes: That's reassuring - I've done about, oh, 35 miles or so total since I got the bike (between weather, as I'm trying to take it easy, and lack of time due to driving so much, lol.)
And, I hadn't ridden a bike since I was 13 or so, until I got this one.
So, good to know it's normal.
(And, I've been trying to keep properly hydrated and all... but I think I WAS thirstiest today...)
The human body is an amazing piece of machinery that somehow even trumps the bicycle in its elegance, but not in its simplicity. The human body requires a lot of variables to be in spec in order to work properly. Hydration and nutrition are two of the most obvious. Don't forget about riding position, rest, and the value of pacing your effort. In time, your body will adjust to being used this way, and you will in turn learn what works for you. What you're experiencing is your body saying "Whoa, there, buddy! This isn't right!"
Part of it is just the usual routine of muscles coming out of hibernation after years of neglect. Your body doesn't know that's "not a problem" and will complain anyways. There could easily be other problems, though, like a seatpost that's adjusted wrong, not enough nutrients to sustain the effort you're putting out, or something else.
I agree with the others, though. Keep riding, remember to stretch before and after riding, watch your nutrition, and get plenty of rest. If you're like me and went from a 10-year-long sedentary lifestyle to a suddenly active one, there will be a LOT of changes in what your body wants. Learn to pay close attention to its cues.