Xndurance is a revolutionary athletic performance formula created by athletes for athletes. This formula has a Published, Gold-Standard, third party, double-blind, placebo-controlled, crossover study. Each batch of Xendurance is tested to ensure that it is not contaminated with banned substances to provide additional reassurance for elite athletes. Xndurance is a revolutionary athletic performance formula created by athletes for athletes. This formula has a Published, Gold-Standard, third party, double-blind, placebo-controlled, crossover study. Each batch of Xendurance is tested to ensure that it is not contaminated with banned substances to provide additional reassurance for elite athletes.