A student who takes part in running sports for the fall, winter and summer seasons and lacks basic social skills. They usually travel together in groups. Due to their social ineptitude and/or lack of esteem given to their sport, they are usually among the least socially threatening, but most insulated and bizzare cliques that one encounters in high school.
Note that not all runners are trackheads, but all trackheads are runners.
"What are the Trackheads doing now?"
"It looks like they're trying to break each other."
"Like a Horse"
"seems that way"
"Not even they know, man."