Hemodynamic Effect of Handgrip During Cyclic Exercise: Study Protocol for a Randomized Crossover Clinical Trial

Objective: To test the hypothesis that isometric contraction with the Handgrip device modulates the response of heart rate, systolic and diastolic blood pressure, double product, and subjective perception of exertion (Borg) during cyclic exercise. Method : This randomized crossover clinical trial consists of three intervention arms. Forty male volunteers aged between 20 and 30 will be recruited. After screening, the volunteers will be randomized to treatment protocols (I: without HG; II: with HG at 30% of Handgrip Strength - HGS and III: with HG at 50% of HGS) which involve performing cyclic exercise on a treadmill, with four sprints at moderate intensity. The data will be presented by the variation (∆) of the sprint-rest and post-exercise-rest moments. The one-way Analysis of Variance (ANOVA) test will be performed in the case of symmetrical distribution and Kruskal-Wallys for non-parametric distribution, to analyze the three protocols during the same phases and then the same test to evaluate the individual responses over time. A p≤0.05 will be considered statistically significant. Impact of the project: This study will provide answers to the hemodynamic effects of isometric activity with handgrip associated with cyclic exercise and, if the hypotheses of this study are confirmed, we will have robust mechanistic evidence to broaden the field of scientific exploration in different clinical contexts. Clinical trial registration: Brazilian Registry of Clinical Trials (REBEC): RBR-78fhyrf, registered on November 17, 2023. Funding : Postgraduate Support Program for Private IES (PROSUP - CAPES) of the Bahiana School of Medicine and Public Health.