Effects of exercise training on baroreflex control of the cardiovascular system

Dynamic exercise training has been recommended as an antihypertensive therapy and as a way to modify the effects of many cardiovascular risk factors (Arakawa, 1993; Arroll and Beaglehole, 1992; Kelly and McClellan, 1994: see references 1-3 in the paper). However, the mechanisms underlying the blood-pressure lowering effect of chronic exercise are still poorly understood. It has been suggested that a decrease in sympathetic tone is one of the major effects elicited by chronic exercise on the cardiovascular system. The importance of the sympathetic component is confirmed in this review, since it was found that in spontaneously hypertensive rats (SHR) a marked decrease in sympathetic activity occurred after exercise training. Moreover, our findings suggest that this effect is mediated by improving the depressed baroreceptor function, which is, in part, responsible for the attenuation of the baroreflex sensitivity observed in the sedentary SHR (Krieger et al., 1998, 1999; see references 4 and 5 in the paper).