Sympathetic nervous system: aging and exercise.

Both aging and exercise are associated with alterations in regulation of catecholamines. With aging, elevated circulating catecholamines at rest and after stress may result in increased sympathetic nervous system activity. The ability of the catecholaminergic system of older subjects to respond and adapt to environmental challenges is altered during aging. One consequence of these changes may be the increased prevalence of hypertension with age. Exercise training reduces both systolic and diastolic blood pressure in young and elderly hypertensive subjects. The reduction in catecholamine synthesis after training may be linked to the beneficial effects of exercise in hypertensive individuals.