Consumption of energy drinks on cardiovascular and metabolic response and performance. Is there an effect?

Abstract

Over the years, the search for nutritional strategies that promote improved sports performance has increased. Among the available options, energy drinks appear as potential nutritional resources for this purpose, because they offer, in addition to caffeine, substances that act synergistically to improve performance, such as taurine, carbohydrates, amino acids, vitamins and minerals, promoting improved performance for both amateur and professional athletes. The aim of the study was to verify the effects of ingesting energy drinks with (ED1) and without carbohydrates (ED0) containing 2 mg·kg-1 of caffeine, and a decaffeinated placebo (PL) on cardiovascular, metabolic and performance parameters during cycling. Twelve male cyclists (age = 24.4 ± 6.6 years old) volunteered to participate in this study. The protocol consisted of three experimental sessions of 60 min of continuous cycling (65-75% of VO2maxE) followed by time-trial 6 km. The subjects ingested ED1, ED0 or a placebo drink (PL) 40 min before beginning the exercise. The heart rate (HR), blood pressure (BP), plasma glucose and lactate concentrations, and the time taken to complete the 6 km time-trial were evaluated. The time taken to complete the time-trial was significantly higher (p < 0.05) in the PL group than in the groups ED1 and ED0. This time significantly decreased after the ED1 consumption relative to that for the ED0 consumption. Heart rate, systolic and diastolic arterial pressure and in the plasma glucose and lactate concentrations were similar in all the considered groups. These results demonstrate that ED1 consumption appears to be more effective at maximizing performance during the last 6 km.