Caffeine & Endurance: What Is Your Protocol?
I recently recorded a podcast with David Hellard about a variety of topics around The Golden Trail Series, which is a shorter distance trail races series that is growing fast and is very competitive. We also spoke a fair bit about caffeine usage for endurance performance. Due to endurance being such a big umbrella of race day intensities, and training protocols, it makes sense that caffeine is likely going to be applied differently across race distances and intensities.
Here are a few characteristics that have been explored regarding caffeine and its application to performance.
Caffeine impacts people differently, which is mostly differences in genetics and exposure.
A small amount, approximately 8-10 percent, of people do not respond to caffeine at all.
The range of both sensitivity and rate of metabolization differs, meaning some may get symptoms of caffeine use with lower inputs (energy, focus, jitters, anxiousness, etc…)
Caffeine’s half life is 5-6 hours (example: if you ingest 100 mg of caffeine, you will likely have 50mg left in your system after 5-6 hours).
After ingestion, effects begin in approximately 15-20 minutes and peak in 45-60 minutes.
Performance dose of caffeine is suggested to be between 3-6 mg per kg of body weight.
Caffeine ingestion increases fat oxidation, meaning it can have a glycogen spraying effect.
Caffeine can increase pain tolerance, and improve cognition. For endurance athletes, this can manifest as a reduction of perceived effort.
The FDA recommends daily limits of 400 mg of caffeine
Chronic caffeine consumption can lower some of its effects, meaning the more you consume the less you will likely notice its impact. However, this does not appear to be true for the fat oxidation improvements. Those likely remain.
Caffeine acts on adenosine receptors. Caffeine binds to adenosine receptors in the brain and blocks them, preventing adenosine from activating them. This prevents adenosine from causing things like tiredness.
Chronic caffeine consumption can increase the levels of adenosine receptors in the brain, resulting in the same amount being less effective.
One question I have played around with, being that I am an ultramarathon runner, is do I really want a performance dose of caffeine? When doing longer ultras like 100 miles, a bigger issue can be going out too fast. Peaking on caffeine too early, by taking a performance dose, may put me in a position of feeling too comfortable and overreaching on what would ultimately be a sustainable pace. Given there is a threshold of how much caffeine I can likely tolerate, it would seem using it at the right time and under the right circumstances would be wise. For these purposes, I prefer a micro dosing approach, where I will take in smaller than the 3-6 mg/kg performance dose more frequently. This is usually in 50-100 mg per serving amounts and between every 1-2 hours. With that said, it still isn’t an all race target. There is some evidence, although not conclusive, that exercise will increase the amount of caffeine you can tolerate as it will aid in how fast it clears. This may be why some people can go well beyond 400mg on race day. For me personally, if I am running a race of approximately 12 hours, I have been able to tolerate approximately 600-800 mg of caffeine. This won’t be the case for everyone, so please just consider this as an example of what I have been able to stress test out of training and racing. I can decide how I want to microdose within that number over the course of the race. Generally, I try to wait as long as I can, and use it to pull me back to the perceived effort I experience early in a race at goal pace. For example, let's say at hour four of a 100 miles I begin to notice my perceived effort creep up at the pace I have been targeting. I will take my first dose of caffeine (between 50-100 mg) at this point. From there I can start spacing out my remaining budget.
Like most things when it comes to race day gear, nutrition, hydration, etc… it is wise to practice what you plan to do in training, so you can have more predictable outcomes when it counts. If caffeine is part of your race strategy, playing around with how you use it is no different.
If interested in my episode with David where we dove into caffeine usage for endurance athletes in the second half of the episode, please check out Human Performance Outliers Podcast - Episode 409: Caffeine Performance & Golden Trail Series.
If you are interested in some additional support, I am currently onboarding for my group coaching package. It is designed for all abilities, and race targets that will help you better understand the training and racing process. It includes: access to my complete catalog of training plans from 5km to 200+ miles, weekly group meetings to help adjust your plan and cover questions/topics, recordings of meetings, future guest speakers, and a private forum for all members. Details can be found here.
Current Picks: here are some endurance training products I currently use, and a list of my favorite endurance books. Enjoy!
Podcast:zachbitter.com/hpo