After seeing the post this morning “How much caffeine on 100mi gravel” I went down a rabbit hole and have a question that I think merits its own topic.
I saw a paper that suggested that caffeine has an approximate half-life in the body of 5.7hrs. So by my math (degree in physics so I’m pretty sure I got this right) that means there is a k value of 0.1216 for caffeine when using hours and we can do some interesting calculations.
Let’s assume a racer has a cup of coffee (100mg) at 7am before a race. If that race starts at 9am, they will still have 78mg of caffeine in their system when the gun goes off. Then if they take a gel with 20mg of caffeine every hour after the start of the race for a 5 hour race, they will end up with 102mg of caffeine in their system at the end of the race.
So, does having 102mg of caffeine in the system mean the racer’s body will experience the same effect of that caffeine as when they took most of that in back earlier in the day? Or does this latent caffeine that’s been in the body for many hours end up losing its effect? Or, finally does the physiological impact of racing mean the caffeine gets cleared faster from the body than when just sitting at a desk typing at a computer so the racer would have less than 102mg?