Radar can be used to detect human heartbeats. This makes radar a potential alternative to today's heartbeat monitoring techniques in medicine. In this paper, two antennas were located on the chest to monitor the heart activity. Simultaneous with the radar measurements, the Electrocardiogram (ECG) and blood pressure were measured. Details of the heart activity, such as opening and closing of heart valves and the filling and ejection of heart chambers, were catched by radar monitoring. Through physical activity, blood pressure as well as the pulse of the person were increased. Matching changes were observed in backscattered radar signal waveforms, thus showing that radar can be used to detect changes in the heartbeat in a reliable way.