Effects of chronic and acute exercise on cardiovascular,&adrenergic responses

AND TAKESHI OGAWA. Effects of chronic and acute exercise on cardiovascular P-adrenergic responses. J. Appl. Physiol. 71(4): 1523-1528, 1991.-+Adrenergic receptor density and respon-siveness may be increased in experimental animals by physical conditioning, and the opposite effects have been observed after a single bout of exercise. To determine whether the chronic and acute effects of exercise include similar alterations in cardiovas-cular function in humans, we characterized heart rate, blood pressure, and distal lower extremity blood flow responses to graded-dose isoproterenol infusion in 15 young healthy sub-jects before and after exercise training and with and without a single preceding bout of prolonged exercise of either low or high intensity (61 t 1 or 82 t 1 % maximal heart rate). VO, mBx was increased 18 % after exercise training (43.2 k 2.7 to 51.1 k 3.3 ml. kg- ’ l min-‘; P c 0.001). Despite a concomitant fall in rest