Killer Workout

Killer Workout

Year: 1987

Runtime: 84 mins

Language: English

Director: David A. Prior

HorrorThrillerThrillers and murder mysteriesGory gruesome and slasher horrorSuspenseful crime thrillers

A seemingly ordinary fitness class turns deadly when a mysterious workout begins claiming victims. Two years earlier, Valerie survived a severe burn after a tanning‑salon accident, and her friend Rhonda now runs the local gym. As members start dying under strange circumstances, the community fears the exercise routine itself may be a lethal trap.

Warning: spoilers below!

Haven’t seen Killer Workout yet? This summary contains major spoilers. Bookmark the page, watch the movie, and come back for the full breakdown. If you're ready, scroll on and relive the story!

Killer Workout (1987) – Full Plot Summary & Ending Explained

Read the complete plot breakdown of Killer Workout (1987), including all key story events, major twists, and the ending explained in detail. Discover what really happened—and what it all means.

A young model, Valerie, is burned in a tanning salon accident. Five years later, Valerie’s twin sister Rhonda Johnson, Marcia Karr, is operating a fitness club in Los Angeles. Rhonda chastises one of her employees, Jaimy, Teresa Van der Woude, for missing an aerobics class she was supposed to lead. Shortly after, a killer brandishing a large safety pin enters the women’s locker room and slashes Rachael, Teresa Truesdale, a client, to death. While closing the club, Jaimy finds her corpse stuffed in a locker, as well as a blood-soaked knitting needle in the locker of Diane Matthews, Laurel Mock. Detective Morgan, David James Campbell, is assigned to the murder case and questions Rhonda and Jaimy.

The next day, Chuck Dawson, Ted Prior, is unexpectedly hired by Rhonda’s senior managing partner of the club. Chuck gets into a physical fight with patron Jimmy Hallik, Fritz Matthews, which impresses club patron Debbie, Jimmy’s ex-girlfriend. Later, Morgan learns that Diane’s knitting needle was not the weapon used to kill Rachael. Later that night, a group of teenagers vandalize the club with spray paint, only to be brutally murdered by an unseen assailant.

The next day, Tom, Richard Bravo, a club patron whom Morgan has deemed a suspect, is murdered in the locker room, and later, Jaimy is found hanged inside the club. Rhonda harangues Morgan for her perceived ineffectiveness of his investigation. Morgan uncovers that Rhonda is in fact Valerie, who survived the tanning accident, and that she never had a twin sister—instead, she legally changed her name to Rhonda and has kept her badly-scarred body hidden with clothing and a wig.

Morgan confronts Rhonda with his discovery, and she admits it, but remains stern and impervious to his assertion that she may be the murderer. Shortly after, Chuck is murdered. Morgan tracks Jimmy to a nearby concrete plant, believing that Jimmy has taken the fall as a suspect given there is no evidence linking him to the crimes. Morgan confronts Jimmy at gunpoint, questioning him if Rhonda committed the murders, but Jimmy manages to incapacitate Morgan. Jimmy returns to the gym and is shot to death by Rhonda, but not before admitting he killed Chuck out of his love for her, hoping to implicate himself to spare her from being suspected by police.

Rhonda claims self-defense, and Jimmy is widely believed to have committed the serial killings. Some time later, Rhonda is brought to a wooded area by Morgan. When asked why they are there, Morgan recounts a story of his police officer father, who enacted vigilante justice against a serial killer whose case was dismissed on a technicality. Knowing that Rhonda will not be prosecuted for her crimes due to Jimmy’s involvement, Morgan attempts to kill Rhonda, but she manages to kill him using a shovel.

Rhonda returns to her gym to oversee it, and is congratulated by her patrons, who herald her as a hero. In her office, she removes the large safety pin from her desk and fondles it, smiling.

Last Updated: October 09, 2025 at 14:38

Mobile App Preview

Coming soon on iOS and Android

The Plot Explained Mobile App

From blockbusters to hidden gems — dive into movie stories anytime, anywhere. Save your favorites, discover plots faster, and never miss a twist again.

Sign up to be the first to know when we launch. Your email stays private — always.

Unlock the Full Story of Killer Workout

Don't stop at just watching — explore Killer Workout in full detail. From the complete plot summary and scene-by-scene timeline to character breakdowns, thematic analysis, and a deep dive into the ending — every page helps you truly understand what Killer Workout is all about. Plus, discover what's next after the movie.

Killer Workout Timeline

Track the full timeline of Killer Workout with every major event arranged chronologically. Perfect for decoding non-linear storytelling, flashbacks, or parallel narratives with a clear scene-by-scene breakdown.

Killer Workout Timeline

Characters, Settings & Themes in Killer Workout

Discover the characters, locations, and core themes that shape Killer Workout. Get insights into symbolic elements, setting significance, and deeper narrative meaning — ideal for thematic analysis and movie breakdowns.

Characters, Settings & Themes in Killer Workout

More About Killer Workout

Visit What's After the Movie to explore more about Killer Workout: box office results, cast and crew info, production details, post-credit scenes, and external links — all in one place for movie fans and researchers.

More About Killer Workout

Similar Movies to Killer Workout

Discover movies like Killer Workout that share similar genres, themes, and storytelling elements. Whether you’re drawn to the atmosphere, character arcs, or plot structure, these curated recommendations will help you explore more films you’ll love.