Resumen de Caffeinated Energy Drinks Improve Volleyball Performance in Elite Female Players.
Alberto Pérez López, Juan del Coso Garrigós, Juan José Salinero Martín, Javier Abián Vicén, David Valadés Cerrato, Cristina Gonzalez, Beatriz Lara, Cesar Hernandez, Francisco Areces Corcuera
AB Purpose: The objective of this study is to determine the effects of a caffeine-containing energy drink on female volleyball players' performance. Methods: Thirteen elite female volleyball players ingested 3 mg[middle dot]kg-1 of caffeine with an energy drink or the same drink without caffeine (placebo drink) in a double-blind and randomized study. Then, participants performed the following: standing spike, jumping spike, spike jump, blocking jump, squat jump, countermovement jump, manual dynamometry, and the agility t-test. A simulated volleyball game was played, videotaped, and notated afterward. Results: In comparison to the placebo drink, the ingestion of the caffeinated energy drink increased the ball velocity in the standing spike (19.2 +/- 2.1 vs 19.7 +/- 1.9 m[middle dot]s-1, P = 0.023) and in the jumping spike (17.9 +/- 2.2 vs 18.8 +/- 2.2 m[middle dot]s-1, P = 0.038) and the jump height in the squat jump (28.1 +/- 3.2 vs 29.4 +/- 3.6 cm, P = 0.028), countermovement jump (32.0 +/- 4.6 vs 33.1 +/- 4.5 cm, P = 0.018), spike jump (43.3 +/- 4.7 vs 44.4 +/- 5.0 cm, P = 0.025), and block jump (35.2 +/- 5.1 vs 36.1 +/- 5.1 cm, P = 0.044). Furthermore, the caffeinated energy drink decreased the time needed to complete the agility t-test (11.1 +/- 0.5 vs 10.9 +/- 0.3 s, P = 0.036). During the game, the volleyball actions categorized as successful were more frequent with the caffeinated energy drink (34% +/- 9% vs 45% +/- 9%, P < 0.001), whereas imprecise actions decreased (28% +/- 7% vs 14% +/- 9%, P < 0.001) when compared with the placebo drink. Conclusion: Commercially available energy drinks can significantly improve physical performance in female volleyball players. Increased physical performance led to improved accuracy during an actual volleyball match.
