Well some people thought your problem was "overtraining". Overtraining is usually applied to a fit athelete who goes out and does more mileage at a higher intensity then their body can endure and instead of getting improving their performance slides. Usually, people who do this report an elevated resting heart rate.
Shoot I have put in lots and lots of miles in weeks and this has never happened to me. I think I do ok because my talent is endurance (I suspect I don't have a fast twitch muscle fiber). And if I ride hard one day and feel it on the next ride, I just back off some and recover. Quite a few people don't listen to their body and their body makes them pay.
I think I know what happened here. If after a ride, your legs feel weak, sore, or like jelly, it means you rode pretty hard and your legs are a little beaten up. GOOD. That means you had a good intense workout it also means taht you need to rest and let your legs recover. Take it easy tomorrow (you can ride but only do what feels ok).