In Men, Caffeine Is More Effective And Starts Working In 10 Minutes
http://www.scientificblogging.com/news_releases/men_caffeine_more_effective_and_starts_working_10_minutes --- A study headed by researchers from the University of Barcelona (UB) shows that caffeine has a greater effect on men than women, and that these effects start just 10 minutes after it is drunk. In addition, contrary to what was previously thought, it has also been shown that decaffeinated coffee also produces an increased state of alertness.