KOOM

Initialism combo of "King Of Mountain, KOM" from Strava and Oof, which means to expressing discomfort, as from sudden exertion or a blow to one's body; King OOf Mountain, KOOM.

Chad: "I saw the seggie on my garmin, tossed back 5 jetberry Gü's, and Zone 6'd my heart-rate for a KOOM."

Fred: "Bro that can't be good for your health."

Chad: "You wouldn't get it."