This report summarizes work concerning the exercise pressor reflex performed in my laboratory over the past 20 years or so. It is part of a symposium held to celebrate the 40th anniversary of two publications by Dr Jere Mitchell that appeared in The Journal of Physiology. For the most part, this report concerns itself with the discharge properties of group III and IV muscle afferents. Particular attention has been paid to their responses to arterial injection of putative metabolic byproducts of muscular contraction as well as their responses to both static contraction and dynamic exercise.