In the past 4 years the investigators' research group has completed 2 studies on the effect of testosterone therapy on exercise induced coronary ischaemia (clinically manifest as angina pectoris). We, the investigators at Sheffield Teaching Hospitals, have shown that testosterone replacement therapy improved exercise duration on the treadmill and prolonged time to ischaemia (ischaemic threshold). Moreover, we demonstrated a dose response relationship between the increase in exercise duration and the baseline testosterone level so that men with lower baseline testosterone level derived the greatest symptomatic benefit from replacement therapy. Importantly we have also demonstrated that the effects of testosterone are maintained in the presence of concomitant anti-anginal drug therapy and at physiological levels of testosterone therapy. (English et al. 2000; Malkin 2004)