Originally Posted by jrossbeck

It's not unusual. Especially if you rampe dup from 20 to 30 miles. That's a 50% jump, and many fitness "gurus" will tell you to only increase mileage in distance sports by 10% at a time.

If I had to guess, I would assume your form broke down in the last 10 or so miles. Try to ride more than once a week, and focus on keeping your elbows bent, wrists soft and try to absorb any bumps vs. tightening up when you hit them. As far as the legs - again, make sure you are in the proper gears, keep your tempo yup around 90 rpm or so, etc.