EFEITO DA MASSA MUSCULAR DO EXERCÍCIO ISOMÉTRICO NAS RESPOSTAS CARDIOVASCULARES AGUDAS EM JOVENS SAUDÁVEIS: ESTUDO CROSS-OVER RANDOMIZADO CONTROLADO

Exercício isométrico e respostas cardiovasculares

Abstract

It is known that the greater muscle mass involved in dynamic strength exercise promotes greater acute reduction in blood pressure. On the other hand, the effects of muscle mass in isometric strength exercise on blood pressure are not known. For this, the aim this study was to compare the acute cardiovascular responses of isometric exercise with different muscle masses in healthy young people. In this randomized controlled trial with a cross-over design, 12 healthy young men performed, in random order, four experimental sessions: isometric exercise with bilateral handgrip (SH), isometric wall squat exercise (SA), combined session of SH and SA (SCOMB) and session control (SC). All isometric exercise sessions had 4 sets of 2 minutes each. Blood pressure, heart rate and double product were evaluated before and 15, 30, 45 and 60 minutes after the sessions. There was no reduction in blood pressure after isometric strength exercise (p>0.05 for all). Heart rate was reduced after SH (70.3±8.3 vs. 66.1±8.0 bpm), while in SA (70.9±13.6 vs. 74.1±12.8 bpm) and SCOMB (69.5±9.6 vs. 69.8 ± 10.1 bpm), there was an increase (p<0.05 for all). The double product was lower after SH (8563±1689 vs.7869±1422 bpm*mmHg) than after SA (8589±1946 vs. 8965±1670bpm*mmHg), while in SCOMB, it did not show significant differences. In conclusion, the muscle mass involved in isometric exercise did not affect blood pressure responses, however, the session with the lowest muscle mass promoted a reduction in heart rate and double product in healthy young people.