This post is taken from the Vitamin. Every Thursday, I drop some knowledge bombs on your face to help you reach your goals faster while avoiding all the bullshit.
There’s a good chance you consume caffeine as a pre-workout supplement to improve your workout performance. And rightfully so. Caffeine’s ergogenic benefits (i.e., performance-enhancing) are well documented. But we (including yours truly) don’t just limit our caffeine intake to the pre-workout window; our days are filled with a steady stream of coffee, tea, energy and diet drinks, all of which come packed with caffeine.
If you are a caffeine-fiend (and, let’s be honest, who isn’t?), there’s an equally good chance you’ve heard people recommend “cycling off” caffeine every now and then to resensitize yourself to caffeine’s benefits.
But is this actually true–do you need to go cold turkey for a while to reap the performance-enhancing benefits of caffeine?
Carvalho et al. (2022) conducted a systematic review and meta-analysis to determine how habitual caffeine consumption affected caffeine’s effect on acute exercise performance.
What did the researchers do?
A total of 59 studies were included in the final review, which consisted of 1,137 individuals (958 men and 179 women). Of these:
- 958 were men and 179 were women.
- 718 were trained, 400 were untrained, and 19 were classified as elite.
From here, three-level meta-analyses were performed on outcomes within endurance, strength, or power exercise tests, and within studies including males or females (except for those which combined both sexes) and trained or untrained individuals.
The researchers also conducted meta-regressions within each of the eight main meta-analyses (overall, endurance, strength, power, males, females, trained, untrained) to see how habitual caffeine consumption (in mg/kg BM/day) affected each of these individual variables.
In addition, the researchers also looked at the overall influence of:
- The acute relative caffeine dose (<3 mg/kg BM, 3–6 mg/kg BM, and>6 mg/kg BM).
- Whether the acute caffeine dose provided was lower or higher than the mean daily dose of caffeine habitually ingested by participants.
- The caffeine withdrawal period prior to the intervention (<24 h, 24–48 h, and>48 h).
- Studies had to be in English, peer-reviewed and conducted in healthy humans of any age and training status (i.e., beginner, intermediate, advanced).
- Meta-analyses were conducted on studies that had evaluated habitual caffeine consumption in mg/kg BM/day or that could be calculated as such using participant data (i.e., provided mean BM and mean absolute daily caffeine consumption).
- The intervention required acute caffeine supplementation at any dose or in any form (capsule, tablet, beverage, coffee, and gum) prior to an exercise task, with a placebo session or group required as the comparator.
- For the outcomes, studies must have evaluated exercise performance or capacity in a randomised single- or double-blind parallel-group or cross-over study design.
What did the researchers find?
Habitual caffeine consumption
The results showed no influence of relative habitual caffeine consumption (mg/kg BM/day) on the effects of caffeine.
Sub-analysis by caffeine dose showed a significant effect of caffeine supplementation when doses were <3mg/kg BM and between 3 and 6mg/kg BM, but not >6mg/kg BM.
Caffeine dose higher or lower than habitual consumption
There was a significant effect of caffeine both when the acute dose was higher and lower than the habitually consumed daily dose of caffeine.
Caffeine withdrawal before intervention
Caffeine supplementation showed a significant effect regardless of the time of withdrawal prior to the intervention (<24 hrs, 24-48 hrs, >48 hrs).
Similarly, within the exercise type subgroups (endurance, strength, and power) there was no influence of habitual caffeine consumption.
Males/ females and trained/untrained
Habitual caffeine intake also had no effect on acute exercise performance when considering male and female participants and trained/untrained participants.
This systematic review and meta-analysis suggests even people who consume a lot of caffeine, compared with low caffeine consumers, can still benefit from pre-workout caffeine supplementation, with this effect holding true across a range of exercise types (endurance, strength, and power), gender, and training status of the individual.
Further, a pre-exercise dose of caffeine lower than what you usually consume seems to be just as effective as taking a higher than habitual caffeine dose, so there likely isn’t a need to exaggerate your pre-workout caffeine intake. Interestingly, this study found the ergogenic effects of caffeine were only present in doses up to 6mg/kg BM, but not when this amount was exceeded. The researchers noted too much caffeine could have the opposite effect due to the increased risk of side effects, such as nausea, anxiety, and insomnia.
The present study also found no reason to cycle off or withdraw from caffeine use for an extended period to amplify its benefits. As the researchers explain:
These data are in direct disagreement with this notion and suggest that caffeine withdrawal is unnecessary to elicit performance improvements with caffeine supplementation, with signifcant improvements when withdrawal was<24 h, between 24 and 48 h, and>48 h.
Going on to say:
Thus, what seems apparent is that even with little to no withdrawal, there is an ergogenic effect of caffeine.
Now, this is the part where I have to spoil the caffeine-filled celebrations. While caffeine may provide ergogenic benefits regardless of your habitual caffeine consumption, I’d posit the people who will see the biggest benefit from pre-workout caffeine are those who have a low to moderate habitual caffeine intake. For those who consume high amounts of caffeine, there may still be some benefit to pre-workout caffeine, but it might not be as potent.
As such, I do think it’s worthwhile to take a look at how much caffeine you’re consuming, and where possible, try to reduce this amount to retain caffeine’s ergogenic benefits.
For example, when I’m not actively dieting, I’ll only have one cup of coffee daily (about 200mg of caffeine); that’s the entirety of my daily caffeine intake. Conversely, when I am dieting, I’ll add an energy drink into the mix (~160mg of caffeine) an hour before training. Even then, I’ll try and hold off on increasing my caffeine intake until the latter half of the cut when I’m a lot leaner and energy begins to lag and training performance begins to suffer.
Remember, caffeine is a drug, and it pays to be mindful not to abuse it.
Thanks for reading. If you enjoyed this, you’d love the Vitamin
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