Bron, yes, Athena (women) and Clydesdales (men) are weight classes in running and tri events (and cycling, I think). Since most participants in these events, or at least most elite participaants, are thin, and weight is such a factor in overall time, these categories have been created. I think the cutoffs are 150 lbs for Athena and 200 for Clydesdales.
Brina
"Truth goes through three stages: first it is ridiculed; then violently opposed; finally, it’s accepted as being self-evident." Schopenhauer