How much caffeine on 100mi gravel

I’m trying to plan out my hydration for Almanzo this weekend. Big cup of coffee in the morning like usual. I’m doing straight water in an Osprey pack and two 24oz bottles on the bike with Nuun Energy tablets in each. My longest ride is 70 and only took one tab near 60. Weather is 50s and rain. :frowning:

wouldn’t go too crazy, and do what you normally use on a long training ride. Caffeine can have odd effects when you’re really smashing the pedals if you aren’t used to it. Good luck!

Personally I just drink a cup in the morning, as this is what i normally do. Then save the caffine gels for the last 1 hour 30 minutes as this is when I usually start to not want to ride any more. I eat a tube of caffeine shot blocks and that is enough for me.

That said everyone is different so as the person above me recommended do what you have tested before. Last thing you want to do is take a bunch of caffeine and have a bad effect to it.

Also, There is 4 water stops on the route check the almanzo site for details. Not sure if this would change your plan at all.

Lastly, I’ll be riding it this year as well. If you see someone on the following bike say hi.


short ride like that I wouldn’t have any caffeine other than the one cup in the morning

One of caffeine’s least touted benefits is that it improves activity of glut-4 in the gut. So glucose transport is improved. Because of this I like to start the race in a caffeinated state. So I’ll take a couple hundred mg of caffeine 30 to 40 minutes before the race. I’ll continue to consume another couple hundred mg of caffeine in metered doses throughout the race.

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I ended up going down a rabbit hole after seeing this question, and it turns out caffeine has a half-life of 5.7 hours. That means that if your race takes 6 hours, and you have 100mg (a normal cup of coffee) an hour before the start, you’ll still have 43mg in your body as you cross the finish line.

I don’t know how racing affects that half-life calculation (I created a new post on that) but it seems on the face of it that the caffeine will stay in your system pretty long, and even taking a couple gels with 20mg in them can keep your right around 100mg by doing just the straight math.

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Sorry, that’s wrong. Half life of caffeine can be highly variable between individuals and male/female. Off the top of my head from what I remember it can range from 3-10 hours. There’s an environmental component (exposure to caffeine leads to tolerance and the ramp up in expression of liver enzymes that break down caffeine) and a genetic component (there was a SNP, forgot which one but can easily look it up, that confers a higher rate of metabolism or lower rate).

The wrong part is that I didn’t include the uncertainty in the number. Sorry about that.

But in terms of half-life numbers, even 3-10hr isn’t that big of a swing. In the two examples I gave the results look like 31mg and 61mg for the 3 hour extreme case. 66mg and 117mg for the 10 hour extreme case. It still begs the question, what is the effect? In the other thread you were mentioning that the receptors get desensitized so 100mg sloshing around 5 hours after your first cup of coffee isn’t as “effective.” In the end it sounds like we all just need to do a bunch of experiments on ourselves to figure out what works for us individually.

From experience I wouldn’t experiment with caffeine this close to a race, I’ve found it’s had negative impacts.
I can’t say how or why but I worked on caffeine peak time and when to supplement a few times and it never worked.

However, towards the end of 100km gravel ride recently I took a caffeine shot and it worked. The thing is I had a normal cup of coffee in the morning and caffeine didn’t feature in my nutrition strategy other than “in case I need it”

It is a big swing if you look at realistic doses intending to improve performance. The numbers you’re using for caffeine in that hypothetical situation is too low. The recommended baseline for dosage is 3mg/kg. Some can tolerate upwards of 5mg/kg or more. For someone that’s 80kg the difference in rates of metabolism could be the difference between therapeutic levels of caffeine, sub therapeutic and toxic at 4 hours post maximal absorption.

I think you’re responding to another person on the other thread. Not me mentioning the stuff about tolerance.

Nice! Should bet a wet one.