Purpose: To evaluate the influence of physical fitness on the metabolic and perceptual responses to chest compression-only (CCO) CPR. Methods: In a counterbalanced design, forty-seven CPR-certified participants were randomized to perform: 1) a fitness assessment in which muscular (e.g., push-ups = PU) and cardiorespiratory endurance (e.g., step test recovery heart rate = RHR) were determined, and 2) a 10-minute CCO-CPR trial in which the heart rate (HR) response and ratings of perceived exertion (RPE) were determined. Results: Both PU and RHR were significantly correlated to the HR response to CCO-CPR (r = - 0.45, p < 0.01; r = 0.54, p < 0.001). PU were significantly correlated to RPE: local muscular (r = - 0.43; p < 0.01), central (r = - 0.45; p < 0.01), and over-all (r = - 0.39; p < 0.01). Conclusions: Greater physical fitness lessens the metabolic and perceptual strain to CCO-CPR. / by Adam J. Berrones. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.