Caffeine and I don’t get along very well so I don’t get the whole addiction but a recent study makes me wish I could turn to a cup of coffee when I’m super tired and still need to function.
First a little about how caffeine works. It takes about an hour for caffeine to reach maximum concentration in your blood (chewing caffeinated gum increases the concentration faster, consuming caffeine with a meal slows it down). Then the effects last for 3-5 hours depending on a bunch of factors like whether or not you’re a smoker.
It acts by binding to receptors designed for a natural body chemical called adenosine which is heavily involved in really short term energy storage in your body. When adenosine binds to its receptors it actually reduces the amounts (inhibits) of other chemicals that are released. These other chemicals are therefore found in higher concentrations in the presence of caffeine. What are the other chemicals? They are noradrenaline, serotonin, glutamate, dopamine, and acetylcholine.
Some of the mental effects of this change is improved reaction time, improved vigilance, and improved attention. There are limited studies regarding higher order skills like decision making and problem solving, and those that do exist show mixed results.
Caffeine can also impact how anxious someone feels but this depends on whether they were sleep deprived, in which case caffeine helps to decrease anxiety, or well rested, in which case caffeine increases anxiety. The size of the dose also affects anxiety with low doses decreasing it and high doses doing the opposite.
In terms of sport performance, caffeine used to be a banned substance for athletes, sort of. The threshold level you were allowed was high enough that you had to purposely consume a lot of caffeine to go over it. A recent study found that only triathletes, cyclists, and rowers consistently test at levels higher than the previous limit. But it does enhance performance below that level.
There is a reason that it is endurance athletes who are testing at higher levels – all of the benefits relate to endurance. Moderate caffeine levels improved general endurance, muscular strength and endurance, and reduced pain sensation during endurance activities. There does appear to be individual differences in the impact with some people experiencing no benefit from caffeine.
For a drug to be banned in sport it needs to do more than just enhance performance, it also needs to go against the nature of sport (not sure how the determine that) or cause health concern. There are maximum recommended intakes for caffeine (outside of sport), because beyond that level there is greater potential for negative effects. If you ban caffeine based on the performance enhancing levels it falls well under the level for health risks, which is probably why it was removed from the banned list (I couldn’t actually find their reasoning).
So, the end of the story is that in many situations caffeine is a completely viable performance enhancing drugs whether you are competing in a sport (just not ones that take less than 60 seconds), completing a monotonous or tedious task, or biking (driving) home after a long work day. Too bad it will never help me.
McLellan, Tom M., Caldwell, John A., Lieberman, Harris R., A Review of Caffeine’s Effects on Cognitive, Physical and Occupational Performance.Neuroscience and Biobehavioral Review http://dx.doi.org/10.1016/j.neubiorev.2016.09.001