Effects of caffeinated energy drinks on cardiovascular responses during exercise in healthy adults: a systematic review and meta-analysis of randomized controlled trials

Abstract

The impact of caffeinated energy drinks (CEDs) on the cardiovascular (CV) response to exercise has not been well described. A systematic review and meta-analysis was conducted on the acute effects of CEDs on CV responses during dynamic, aerobic exercise in 296 healthy adult males (224) and females (72) in 21 randomized controlled trials. During exercise, there was an increase in heart rate (HR) (mean difference (MD), 2.86 bpm, 95% CI, 2.39–3.34 bpm, I2 = 0%, p < 0.00001), and systolic blood pressure (SBP) (MD, 9.02 mm Hg, 95% CI, 4.25–13.79 mm Hg, I2 = 0%, p = 0.0002) with consumption of CEDs, compared with controls, but diastolic blood pressure was similar. Insufficient data were available to evaluate rate pressure product (HR × SBP) and exercise-induced arrhythmia. Though changes to HR during exercise were modest, the significant increase in exercise SBP highlights the importance of directly assessing CV effects of CEDs with exercise, especially in individuals prone to hypertension. Novelty: Exercise SBP in healthy adults is significantly increased during exercise with the consumption of CEDs compared with controls, despite limited data. The direct assessment of CV effects of CEDs with exercise highlights the particular relevance to individuals prone to hypertension.