Exercise often has a positive impact on quality of life, from mental well-being to reducing the likelihood of health-related diseases. Despite these benefits, many individuals do not exercise. Research suggests that boredom, or a lack of reinforcement, can be a reason for low exercise levels. Feedback has been used widely in the literature and, in some cases, can act as a reinforcer. Heart rate feedback is real-time information during exercise. Therefore, the primary purpose of the study was to evaluate the effect of heart rate feedback on participant-initiated modifications to exercise intensity during treadmill exercise of three neurotypical women. Two out of three participants increased the frequency of physical intensity modifications during heartrate feedback sessions (M = 97%). The methods of this study successfully increased how often two out of three participants modified the physical intensity of their exercise behavior while receiving heart rate feedback.