Common warning signs of overtraining include:

Washed-out feeling, tired, drained, lack of energy
Mild leg soreness, general aches and pains
Pain in muscles and joints
Sudden drop in performance
Insomnia
Headaches
Decreased immunity (increased number of colds, and sore throats)
Decrease in training capacity / intensity
Moodiness and irritability
Depression
Loss of enthusiasm for the sport
Decreased appetite
Increased incidence of injuries.
A compulsive need to exercise

Had the brilliant insight the other day what if my decreased capacity and sudden drop in performance was because I was overtrained…. On one hand it is kind of embarassing to speculate that little old me and the tiny bit of exercise that I was doing was enough to overtrain — but then, might that not also fall under “a compulsive need to exercise”?