I am only a weekend warrior, around 2 rides a month. I usually go around 30-40 miles for a ride. I often find that for the rest of the day after a ride, I am really crabby and have a head ache. I figure it would be one to two things: 1) dehydration - I try to drink a fair amount of water on the ride, and once I finish I drink a lot, or 2) I pushed my body past my current fitness level and I just need to exercise more.
Has anyone experience this type of thing? Any suggestions?