Effect of Energy Drink on Sport Performance and Psycho-Physiological Responses.

Each participant visited the laboratory for two formal test sessions, drinking a caffeine-containing ED (RB) and a caffeine and taurine free beverage drink (PL). All sessions were arranged in the early evening hours to avoid any time of day effects. The two definitive test sessions were separated by an interval of seven days to allow sufficient recovery between tests and to ensure caffeine washout. To avoid identification, two opaque and unmarked cans of RB or PL were ingested by each participant (i.e., 500 mL) in the presence of a researcher. The two drinks were similar in volume, texture, and appearance. One can of RB drink (i.e., 250ml) contained 80 mg of caffeine, 1 g of taurine, 27 g of carbohydrates, 0.6 g of protein, 5 mg vitamin B6 and 487 kJ of energy.

The PL drink was prepared by an agri-food engineer; it did not contain any caffeine or taurine, but comprised carbonated water, carbohydrates, citric acid lemon juice reconstituted from concentrate (1 %), supplemented by flavorings, of sodium citrate, acesulfame K, sucralose, potassium sorbate and RB (a flavoring that contains propylene glycol E1520 (0.23 mL).