Enhancing physical performance in elite junior tennis players with a caffeinated energy drink - Gallo-Salazar, C.; Areces, F.; Abian-Vicen, J.; Lara, B.; Jose Salinero, J.; Gonzalez-Millan, C.; Portillo, J.; Munoz, V.; Juarez, D.; Del Coso, J. (International Journal of Sports Physiology and Performance, 2015)