The effects of three post-exercise conditions on plasma norepinephrine levels in moderately active middle-aged males

Abstract

The purpose of this investigation was to evaluate the effect that three post-exercise conditions had on plasma norepinephrine concentrations following strenuous submaximal exercise in a group of moderately active, middle-aged males. Six healthy, moderately active male volunteers, aged 40 to 52, were evaluated during rest, submaximal treadmill exercise (85 percent previously-determined maximum oxygen consumption) and post-exercise periods on three separate occasions. The post-exercise conditions evaluated included: a slow (2 mph, 0% elevation) continued walk, standing with minimal movement and laying supine with minimal movement. Data concerning the variable of interest, plasma norepinephrine levels, were obtained from blood plasma obtained from an antecubital vein. A univariate, repeated measure, one-way analysis of variance design was employed to analyse the data. The following conclusions were made with respect to the data analyzed for this study. 1. The early post-exercise period following strenuous exercise produces markedly high concentrations of plasma norepinephrine in moderately active, middle-aged males. 2. Recovery in the supine position produced the least elevated plasma norepinephrine concentration throughout recovery of the three post-exercise conditions elevated. 3. Exercise of similar intensity performed at different times evoke a lesser or greater sympathetic response to the same subject.