Most people have probably noticed that the “buzz” of caffeine seems to be a bit less effective if you have it regularly. If you, have it more regularly, it is like you develop a tolerance to it, so you notice the effects less.
Based on this, I’d assume most people would naturally assume the benefits for performance would also decline if it were used overly frequently.
But it is still a question worth asking. Because what if you were an athlete who also liked utilising caffeine for other purposes? Or just liked the taste of coffee?
It’s a question worth asking because there are a few possible outcomes:
- Even though the “buzz” from caffeine is blunted, the improvements in performances remain unchanged.
- Consistent caffeine use makes it less effective when you want it. Which then means you either should use it less frequently or have to put up with the loss of performance related to frequent use.
- Some combination of the above.
Due to this, it makes sense to explore what the research on the topic has shown.
What Are We Defining as “Work for Performance?”
When figuring out whether caffeine works for performance, it makes sense to define what we are talking about.
One thing I will exclude from this discussion is general alertness and cognitive function. Because while that also is an interesting topic, I just want to focus on athletic performance in this article.
The specific criteria I would use as working for athletic performance is: Does it improve performance in a measurable way?
It cannot just be subjective. It has to be a measurable improvement.
We know that caffeine does improve performance through a variety of mechanisms. Having 3-6mg/kg of caffeine 30-60 minutes prior to an exercise session can improve outcomes such as strength, speed, power and endurance.
Obviously you can make arguments for higher or lower dosages than that, but it is a good general guideline.
The next criteria to add onto that is: Does it improve performance to the same extent as it would have with/without caffeine habituation first?
Since we are really trying to figure out if there is a downside to having caffeine regularly, that is why the metric we care about is whether there is a reduced performance benefit, even if there is still some level of benefit.
A Study Indicating Caffeine Habituation Reduces Effectiveness
A 2017 study from the UK got together 18 people who typically averaged a low caffeine intake (<75mg per day).
They then did two trials (60 min cycling at 60% VO2max followed by a 30 min performance test) at the start of the study. One involved a 3mg/kg dose of caffeine. The other involved a placebo.
Obviously in the first test, caffeine outperformed placebo.
The next step involved half the participants consuming 1.5-3mg/kg caffeine daily for 28 days. The other half had a placebo.
Then they underwent testing again on day 29, after consuming 3mg/kg of caffeine.
In this test, the group that consistently consumed caffeine no longer got a performance benefit. The group that had been consuming a placebo DID still get a boost in performance.
This type of research builds a bit of a case for the argument that you should consider having some time away from caffeine in the lead up to a big event. Since theoretically, based on this logic, it would allow you to better reap the rewards of caffeine when you use it.
Research Indicating That Caffeine Habituation Has Minimal/No Impact
A 2017 study from Brazil had 40 cyclists who were allocated into groups based on the following:
- Low consumers (averaging 58mg/day)
- Moderate consumers (averaging 143mg/day)
- High consumers (averaging 351mg/day)
They then did separate time trials following the ingestion of caffeine (6mg/kg) or placebo.
No difference between groups was found, indicating that habitual caffeine intake did not really play much of a role.
Another study on topic had 12 cyclists who regularly consumed caffeine undergo various scenarios.
They main thing compared was a 4-day caffeine withdrawal period followed by 3mg/kg of caffeine prior to a time trial, to the alternative of not abstaining from caffeine.
In this study, abstaining from caffeine for 4-days made no positive difference. This indicates that the habituation affects either did not matter in this case, or that 4 days abstinence was not enough to make a difference.
A Broader Look at The Research
The prior section only touched on a small sub-set of the research. There are a lot of studies that make it looks like caffeine habituation is an issue, and others that do not.
A better area to be focusing on rather than individual studies, is what does the overall body of research on the topic show?
A 2019 review on the topic concluded that caffeine habituation likely does reduce the performance benefits of caffeine a bit. But a proposed solution is simply to go even higher than your normal caffeine dosage, when trying to reap the performance benefits.
An interesting conclusion from this review was that caffeine withdrawal prior to an event offered minimal competitive benefit to habitual users.
This is an interesting practical point. Caffeine withdrawal could contribute to headaches and irritability in somebody who normally has high dosages. Potentially experiencing this for a few days leading up to a competition could have downsides that outweigh any potential upside.
A 2020 review from the ISSN concluded that there were no consistent differences in the performance affects of acute caffeine ingestion between habitual and non-habitual users.
Both reviews highlighted that there are studies that provide evidence for both sides of the argument. But a safe interpretation of the research would be:
- If there is a reduction in the performance benefits of caffeine due to habituation, it likely is not a large/consistent reduction.
- Taking a short break from caffeine prior to consuming it for an event does not seem to consistently improve performance in a significant manner, beyond just continuing normal caffeine consumption.
Practical Takeaway Message
Because there is not a strong conclusion here, there is a lot of room for individualisation.
If you do not habitually consume caffeine, it likely makes sense to keep it that way, and just save it for events that matter.
But if you do consume caffeine regularly there are a few things to consider.
One is that if you choose to take a break from caffeine, there are likely withdrawal symptoms.
From another perspective, the placebo affect could be beneficial. If you have a break, and then consume caffeine, you likely “feel” it more, which could be of benefit.
Another option could be simply to have more caffeine than you normally do.
Or alternatively, you might not decide to change anything since the research is not consistent. And because it is not consistent, it is clearly not a big difference.
There are a lot of options, so it makes sense to do whichever one of these options appeals to you the most personally.