Original articles  CARDIOVASCULAR SYSTEM 

The Journal of Sports Medicine and Physical Fitness 2004 March;44(1):54-62

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

54 Postexercise hypotension and hemodynamics: the role of exercise intensity

Forjaz C. L. M., Cardoso C. G. Jr, Rezk C. C., Santaella D. F., Tinucci T.

School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil

Aim. ­Although post­ex­er­cise hypo­ten­sion (PEH) has ­already ­been exten­sively dem­on­strated, the influ­ence of exer­cise inten­sity on its mag­ni­tude and mech­a­nisms is ­still con­tro­ver­sial.
­Methods. ­Twenty-­three nor­mo­ten­sive sub­jects ­were sub­mitted to a con­trol (45 min­utes of ­rest) and 3 exer­cise ses­sions (­cycle ergom­eter, 45 min­utes at 30%, 50% and 75% of V.O2­peak) to inves­ti­gate the ­role of exer­cise inten­sity on PEH. ­Blood pres­sure (BP - aus­cul­ta­tory), ­heart ­rate (HR - ECG), and car­diac ­output (CO - CO2 ­rebreathing) ­were meas­ured ­before and ­after the con­trol and exer­cise ses­sions.
­Results. Sys­tolic BP ­decreased sig­nif­i­cantly ­after exer­cise at 50% and 75% of V.O2­peak. Dia­stolic BP ­increased sig­nif­i­cantly ­during the con­trol ses­sion, did not ­change ­after exer­cise at 30% of V.O2­peak, and ­decreased sig­nif­i­cantly ­after exer­cise at 50% and 75% of V.O2­peak. ­This ­fall was ­greater and ­longer ­after ­more ­intense exer­cise. CO and ­systemic vas­cular resis­tance (SVR) ­responses ­were sim­ilar ­between ses­sions, CO ­increased ­whereas SVR ­decreased sig­nif­i­cantly. ­Stroke ­volume (SV) ­increased and ­heart ­rate (HR) ­decreased fol­lowing con­trol and exer­cise at 30% of V.O2­peak ­whereas SV ­decreased and HR ­increased ­after exer­cise at 50% and 75% of V.O2­peak.
Con­clu­sion. PEH is ­greater and ­longer ­after ­more ­intense exer­cise. BP pro­file is fol­lowed by a ­decrease in SVR and an ­increase in CO, ­what was not influ­enced by pre­vious exer­cise. The ­increase in CO is ­caused by an ­increase in SV ­after ­rest and low inten­sity exer­cise and by an ­increase in HR ­after mod­erate and ­more ­intense ­aerobic exer­cise.