CARDIOVASCULAR RESPONSES AFTER ISOMETRIC HANDGRIP EXERCISE AT DIFFERENT INTENSITIES IN HEALTHY MEN

RESPOSTAS CARDIOVASCULARES APÓS EXERCÍCIO ISOMÉTRICO COM HANDGRIP EM DIFERENTES INTENSIDADES EM HOMENS SAUDÁVEIS

Igor Marcelino da Silva Matheus Ferreira Leonardo Sobrinho Raphael Mendes Ritti-Dias Brunno Phellype Silveira Valença Sobral André Luiz Torres Pirauá Luciano Machado Ferreira Tenório de Oliveira Breno Quintella Farah About the authors

ABSTRACT

The 30% maximal voluntary contraction protocol for isometric handgrip exercise is widely used to improve the cardiovascular system. However, it is unknown whether intensity modulation affects these responses. Objective: To analyze acute cardiovascular responses after isometric handgrip exercise performed at different intensities. Twenty-three healthy men participated in this cross-over study. The volunteers performed three experimental sessions: 4x2 minutes of contraction at 30% (S30) MVC and 4x2 minutes of contraction at 50% (S50) MVC, besides control (CS). Blood pressure (BP) as well as time (SDNN, RMSSD and PNN50) and frequency (LF, HF and LF/HF) domain heart rate variability parameters were obtained before and after sessions. None of the experimental sessions promoted statistically significant changes in systolic and diastolic BP (p> 0.05 for all). After S50, there was a smaller increase in SDNN five minutes after the exercise (S50: +5±6, S30: +20±5, SC: +10±2 ms, p <0.05) and higher LF/HF after 20 minutes (S50: +1.59±0.80, S30: -0.49±0.49, SC: +0.39±0.49, p <0.05) compared to the other sessions. In conclusion, BP responses to isometric handgrip exercise are similar between intensities; however, the most intense exercise promoted a greater increase in sympathetic modulation and decrease in parasympathetic modulation after exercise.

Palavras-chave:
Pressão arterial; Exercício; Treinamento de resistência; Frequência cardíaca

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