XL Caff is a pure caffeine supplement, designed for ease of use and effectiveness. Caffeine has a variety of effects on athletic performance; helping to delay the onset of fatigue during exercise1 as well as improving exercise performance2. Furthermore, other studies show that caffeine helps reduce blood lactate levels during high performance exercise3 and even has an antioxidant effect, reducing markers of stress after exercise4. Finally, caffeine has been shown to aid cognitive abilities, increase concentration and increase cognition after intense exercise5 1. Am J Physiol Regual Integr Comp Physiol, 284, 399-404. 2. Int J Sport Nutr Exerc Metab, 3, 328-42. 3. J Sports Sci, 7, 637-43. 4. Clin Chim Acta, 2, 141- 54. 5. Int J Sports Med, 6, 354-61.