The influence of recovery posture on post-exercise hypotension in normotensive men

Purpose: Postexercise hypotension may be the result of an impaired vasocons trictor response. This hypothesis was investigated by examining the central and peripheral hemodynamic responses during supine and sealed recovery aft er maximal upright exercise. Methods: After supine or seated baseline measu rements, seven normotensive male volunteers completed a graded upright cycl ing protocol to volitional exhaustion. This was immediately followed by eit her supine or seated recovery. Measurements of pulsatile arterial blood pre ssure and central and peripheral hemodynamic variables recorded 30 min befo re exercise were compared with those taken throughout 60 min of recovery. R esults: Compared with baseline, mean arterial pressure (MAP) was reduced af ter exercise (P < 0.05) although the degree of change was not different bet ween the supine (-9 +/- 4 mm Hg) and seated positions (-6 +/- 2 mm Hg). Thi s change in MAP was associated with a reduction in diastolic blood pressure (DBP) (P < 0.05) and arterial pulse pressure (APP) (P < 0.01) for the supi ne and seated positions, respectively. The reduction in APP during seated r ecovery was accompanied by a decline in stroke volume (SV) (P < 0.05), not seen in the supine position, that limited the contribution of cardiac outpu t (CO) to the maintenance of MAP. This effect of seated recovery was compen sated by greater systemic (SVR) and regional vascular resistances in the fo rearm (FVR) and the forearm skin (SkVR(A)). There was also evidence of an a ugmented return of FVR and SLVRA to resting levels in the seated position a fter exercise. Conclusion: The lower peripheral resistance in the supine co mpared with seated recovery position suggests there is potential for greate r vasoconstriction, although this is not evoked to increase blood pressure. This further suggests that the arterial baroreceptor reflex is reset to a lower operating pressure after exercise.