Killer Workout (1987)

After the horrible tanning bed incident that ruined her reputation, fitness fanatic Rhonda Johnson, the co-owner of Rhonda's Workout Fitness Club in Los Angeles, tries to find her feet. Having devoted herself to shaping perfect bodies, Rhonda gets back to square one when a stealthy serial killer on the loose targets the health spa's unsuspecting customers. And as Rhonda's members die left and right, questions arise. Who is behind the outburst of Lycra violence? Can hard-boiled Detective Morgan stop the psychopath before more innocents die?