Killer Workout

In this campy, low-rent slasher schlock from the mid-80s, a young woman named Valerie was burned after entering a tanning salon two years prior to opening a gym in Los Angeles where all of a sudden, people are being murdered. The victims include women who work out, mostly aerobics, and a few patrons who wander into the wrong part of the gym at the wrong time. As Detective Morgan investigates the gruesome killings, he discovers that Rhonda Johnson, Valerie's twin sister, is actually the prime suspect, but her identity remains hidden beneath layers of clothing and makeup until it's too late for anyone to stop her from becoming the killer she always was.