Caffeine

Source: Bicyling Magazine

Caffeine has long been demonized as a diuretic.  On paper, that means it should lead to dehydration and heat stress, especially when you consider that it also raises your heart rate and increases your metabolism.

A review of ongoing research recently revealed that caffeinated drinks don’t make you pee that much more than equal amounts of beverages without the buzz.  The stimulant also doesn’t worsen the effects of summertime heat.  In fact, caffeine makes you feel better.  Numerous studies have shown that it lowers your rate of perceived exertion while improving your strength, endurance and mental performance.  Even better, researches from the University of Birmingham, in England, found that riders who drank a caffeinated sports beverage burned the drinks carbs 26 percent faster than those who consumed a non-caffeinated sports drink, likely because caffeine speeds glucose absorption in the intestine.