Effects of different intensities of sedentary behavior interruption on cardiovascular parameters and muscle activity in healthy adults: study protocol

Abstract

Sedentary behavior is a relevant risk factor for cardiovascular, autonomic, and muscular alterations, even in physically active adults. Regular interruption of sedentary behavior has been proposed as a non-pharmacological strategy to attenuate these adverse effects; however, studies comparing different interruption intensities remain scarce. This article describes the protocol of a randomized, crossover, and controlled clinical trial aimed at analyzing the effects of interrupting sedentary behavior with light- and moderate-intensity physical activities, compared with uninterrupted sedentary behavior, on cardiovascular parameters, muscle activity, and autonomic function in healthy adults. Twenty-one participants will be exposed to three experimental conditions: uninterrupted sedentary behavior, sedentary behavior interrupted by light-intensity physical activity, and sedentary behavior interrupted by moderate-intensity physical activity. Blood pressure, heart rate, heart rate variability, electromyographic muscle activity, and skin temperature will be assessed throughout the experimental sessions. Data analysis will be performed using linear mixed models, with a significance level set at 5%. It is expected that interruptions, particularly at moderate intensity, will elicit more favorable physiological responses, contributing to the advancement of knowledge and supporting recommendations aimed at reducing sedentary time and promoting cardiovascular and muscular health. The study protocol is registered in the Brazilian Clinical Trials Registry under number RBR-7dx6s84.