Caffeine blocks adenosine, the brain chemical that makes you feel tired. Less adenosine means more alertness, more focus, and a greater willingness to suffer. On top of that, ...

A few chemical processes can remove the caffeine from coffee beans. Andy Brunning/Compound Interest, CC BY-NC. As in the Swiss water method, the producers can reuse the “caffeine-free” water ...

Caffeine is a chemical that stimulates your central nervous system as well as your muscles, heart, and other parts of your body that help control blood pressure.