Why do many top athletes drink coffee? Probably because they enjoy the taste. But also because research shows caffeine can enhance athletic performance. And it's perfectly legal! Read more about how many top athletes competing in Rio make coffee part of their training regimen:
WSJ - Caffeine - the performance enhancer in your kitchen:
http://www.wsj.com/articles/caffeine-the-performance-enhancer-in-your-kitchen-1469457168
ESPN - Coffee - Secret training tool of top athletes:
http://www.espn.com/espnw/life-style/article/14982505/but-first-coffee-secret-training-tool-top-athletes
NY Daily News - Olympic athletes disappointed about not having coffee in the village:
http://www.nydailynews.com/sports/more-sports/won-rio-olympics-article-1.2738876