Caffeine is the most popular psychoactive drug in the world[i]. Many athletes believe that caffeine has performance-enhancing properties and so they use caffeine in training and racing. A large body of scientific study confirms their belief. Caffeine has been proven to enhance short-term power and long-term endurance. It also has a mental impact. Not only does caffeine increase awareness and concentration, it also lowers perceived exertion, allowing athletes to work harder for longer periods.[ii] So, not only can you actually go harder with a little caffeine on board, your perceived exertion is also lower, letting you go harder still.
How, exactly, does caffeine affect your concentration and rate of perceived exertion? Well, it’s actually very complex, as happens with neurology, hormones and musculature.[iii] Boiled down, this is how it looks.
It turns out that caffeine has some interesting properties in relation to other biochemicals. First, there is adrenaline, which caffeine seems to increase in your bloodstream. You have felt the effects of adrenaline coursing through your veins after a sudden scare, such as a near-miss in your car or after narrowly avoiding crashing your bike. That jittery, breathless, foggy, spacy feeling just after that incident is the impact of adrenaline. And caffeine elevates adrenaline in your system. How does that sharpen your focus and impact your RPE? Adrenaline prepares your entire system for action (the almost-cliché of fight or flight), and lowers your pain reception perception.
A second interesting biochemical is dopamine, which promotes good feelings, even inching toward euphoria, and strongly reduces pain perception. Caffeine acts on the same neural connections as does dopamine, mimicking its effects. So does morphine, heroin and cocaine. This relationship with dopamine-like effects is likely what causes caffeine addiction, including the withdrawal symptoms that many caffeine users complain about when they stop using it.
That’s too bad for regular coffee drinkers (80% of the adult U.S. population), because many studies show that the ergogenic effects of caffeine actually diminish with regular use. That means that the athlete needs to refrain from using caffeine for many days (4-30) before the event if she wants to gain a performance boost from caffeine. For regular users, that means risking withdrawal symptoms and forgoing the routine (morning cup of Joe, etc.) that supports the habit.
Because caffeine has a six-hour half-life (six hours after ingesting it, half of that caffeine is gone and half remains), on half- or full-Ironman-distance races, athletes will need to take in some caffeine during the race. Most writers encourage athletes to take caffeine (if they encourage it at all) about two hours before the start of the event. Some gels now have caffeine, and a new sports drink, Zum XR has caffeine and electrolytes contained in timed-release spheres in addition to in solution in the drink, so that you don’t have to continue ingesting caffeine—the time-release spheres do it for you.
Whatever your relationship with caffeine, a purposeful, disciplined dosing strategy may help you keep up your performance and stay sharp all the way through the finish line.
for more information on how to administer caffeine, see my post Does caffeine improve endurance sports performance? on January 30.
[ii] Kolata, Gina (2009) It’s Time to Make a Coffee Run. Retrieved from http://www.nytimes.com/2009/03/26/health/nutrition/26best.html?_r=2&pagewanted=all&
[iii] Graham, Terry et. al. (2000). Caffeine ingestion does not alter carbohydrate or fat metabolism in human skeletal muscle during exercise. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7793.2000.00837.x/full