Efeitos da suplementação com guaraná (paullinia cupana) sobre a variabilidade da frequência cardíaca e parâmetros hemodinâmicos pré e pós-exercício: um ensaio clínico, cruzado, duplo-cego e placebo controlado

Abstract

Objective: The aim of the study was to evaluate the effects of guaraná (Paullinia cupana) supplementation on heart rate variability (HRV) and hemodynamic parameters before and after exercise. Materials and Methods: This randomized, crossover, double-blind, placebo-controlled study included 25 healthy, physically active men (age: 21±2.5 years; weight: 72±8.9 kg; height: 173±6.1 cm), normotensive (≤120/80 mmHg) and habitual caffeine consumers. Participants underwent three treatments: Guaraná, Caffeine, and Placebo. They received 5mg/kg of caffeine in both caffeine and guaraná capsules, with an equal number of placebo capsules, 60 minutes before continuous jump exercise protocol. HRV (RMSSD and SDNN) and hemodynamic parameters (systolic blood pressure [SBP], diastolic blood pressure [DBP], heart rate [HR], and mean arterial pressure [MAP]) were analyzed only during the final 40 minutes of a 60-minute rest period and the 15-minute post-exercise period. Results: In terms of HRV, a significant reduction in RMSSD at rest was observed with guarana supplementation (p < 0.033) compared to both caffeine supplementation and placebo. In the post-exercise, both guarana and caffeine supplementation decreased RMSSD when compared to placebo (both, p < 0.001). Regarding hemodynamic parameters, an increase in SBP was observed with both guarana and caffeine supplementation (both, p < 0.001), regardless of time point. For MAP, an increase was observed only in the caffeine group (p < 0.05) when compared to placebo, irrespective of time point. Conclusion: Guaraná supplementation (5mg/kg caffeine) reduced parasympathetic tone (RMSSD). Additionally, it delayed post-exercise parasympathetic recovery. These effects are likely attributable to the caffeine present in its composition, potentially alongside other bioactive compounds.