Previous studies indicate a 5.5 second latency between a burst of muscle sympathetic nerve activity (MSNA) and the resultant peak blood pressure response, which averages up to 3 mmHg. Aging may attenuate α-adrenergic sensitivity, impair baroreflex function, and hence affect the ability to sympathetically modulate blood pressure. Yet a thorough examination of these relationships in older adults has not been performed. Purpose: To compare the relationship between spontaneous changes in MSNA to changes in blood pressure in young and older men