Patients with autonomic dysfunction have benefited from balancing of parasympathetic and sympathetic activity through the practice of slow breathing exercises. In preliminary studies, patients with various autonomic dysfunctions used biofeedback of respiratory activity to slow breathing to a cadence of six cycles per minute, a frequency known as the resonant frequency (Vaschillo, Vaschillo, & Lehrer, 2006). Breathing at this rate produces cardiovascular resonance (large oscillations in heart rate and blood pressure), forcing the autonomic nervous system to continuously regulate these changes, thereby exercising, and eventually strengthening autonomic control over hemodynamic events. The present study examined several methodologies, such as slow breathing exercises, which are believed to strengthen autonomic control by inducing cardiovascular resonance. Specifically, the current experiment compared different methods of inducing cardiovascular resonance, such as paced breathing and biofeedback assisted protocols. The utility of positive emotion inductions to attenuate respiratory discomfort during slow breathing exercises was also examined. Accurate estimation of the resonant frequency using respiratory methods was largely unsuccessful. However, all respiratory methods produced profound effects in the cardiovascular system, with some differences in the magnitude of effect. In addition, the utility of an emotion induction during slow paced breathing was also demonstrated. The results of this study also support the notion that slow breathing improves pulmonary gas exchange efficiency, in addition to strengthening the baroreflex, by increasing heart rate variability.