Where did Tailwind really come from? Direct experience, testing with endurance athletes here in Durango, Colorado, and some of the best scientific minds studying endurance nutrition:
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Articles of interest to learn more about caffeine and endurance.
International society of sports nutrition position stand: caffeine and performance
Influence of caffeine and carbohydrate feedings on endurance performance
Effect of different protocols of caffeine intake on metabolism and endurance performance
The Effects of Carbohydrate, Caffeine and Protein on Endurance Performance
Caffeine and Sports Performance