Acute effects of energy drink on arterial stiffness and endothelial function in young male bodybuilders with habitual caffeine consumption

Elite bodybuilders consume energy drink (ED) immediately before or during strength training. However, the effects of ED on cardiovascular responses have not been fully understood. In this study, the carotid-femoral pulse wave velocity (cfPWV) and flow-mediated dilation (FMD), which are indices of arterial stiffness and endothelial function in response to acute ED consumption, were examined. Forty-five young men (30.0 ± 3.9 years) were investigated: sedentary (CON, n = 15), physically active (PA, n = 15), and bodybuilders (BD, n = 15). After they consumed commercial ED, their vascular function was analyzed at the following time points: pre, post, 30 min and 60 min. At baseline, the age, height and systolic and diastolic blood pressure of the groups did not significantly differ; conversely, their weight, body mass index, lean mass, fat percent and grip strengths significantly differed (p < 0.05). After ED consumption, central and peripheral blood pressure markedly increased in the PA and CON groups (p < 0.05) but not in the BD group. cfPWV, augmentation index and wave reflection were not different among the groups and did not change at any time point (p > 0.05). However, FMD notably differed among the groups after ED consumption. The FMD of the BD group increased sharply and significantly after ED consumption at post-time points (pre, 6.5% ± 1.7%; post, 13.1% ± 2.6%; 30 min, 10.7% ± 2.9%; 60 min, 8.9% ± 2.4%, p = 0.001). The FMD markedly increased after ED consumption in the PA group (p = 0.004), but it did not change in the CON group (p > 0.05). ED consumption acutely triggered the increase in endothelial function in the BD and PA groups. Therefore, these findings helped elucidate the distinct cardiovascular responses to ED intake among different populations with varying physical activity or training levels.