An initiation or hazing ritual in which a person attempts to perform sit-ups only to have their face strike the exposed buttocks of another who is straddling that person.
In August 1999, four varsity football players at Stevenson High School in Lincolnshire were disciplined for allegedly forcing younger players to do "atomic sit-ups," in which they were blindfolded while doing sit-ups. The upperclassmen dropped their pants and straddled the sophomores so that when the sophomores came up from a sit-up, they hit their faces against the varsity players' buttocks.
William P. Bohlen, "Hazing shadows paths to college," Contra Costa Times, August 29, 2000
The hazing allegedly occurred on at least two occasions about two weeks ago during breaks between the varsity and sophomore teams' morning and afternoon practice sessions, said Weinstein.
In the first incident, four varsity players allegedly instructed as many as 10 sophomores to do an "atomic sit-up," in which the upperclassmen cover the faces of the younger players and hold down their heads with T-shirts while they ordered them to strain to do the exercise, Weinstein said.
Some of the varsity players allegedly dropped their pants and straddled the blindfolded athletes. At that point, the other older players released the T-shirt restraints, causing the victims' heads to bounce against the players' buttocks, Weinstein said.
Jimmy Greenfield and Nancy Ryan, "News," Chicago Tribune, August 31, 1999
Metroplex marvel Darrel Nulisch is at Antone's, Mike Hall and friends perform at Hole in the Wall, Bad Livers are at the Saxon Pub, Mother Tongue and Split are at the Cannibal Club, Blue Train is at Joe's Generic Bar, Aztec Dreamer, O.S.O. and Atomic Sit-Ups play Steamboat.
Michael Point, "Best bets," Austin-American Statesman, December 9, 1991