I’ve previously written about this in Dutch. And although I never write stuff on this blog in English, I’ve decided to translate this one since I’ve seen this question being repeatedly asked on the internet.
About two decades ago the Belgians of the Catholic University Leuven published a study named ‘Caffeine counteracts the ergogenic action of muscle creatine loading’ . Well, that’s fucked up. Everybody loves creatine and everybody loves their caffeine-enriched beverages. And now we have to choose?! No, of course not. In this article I’ll explain to you why you can take caffeine and creatine in conjunction, so you don’t have to choose between these two lovely miracles of nature.
So what were these guys up to in this creatine & caffeine study?
Vandenberghe and his co-workers of the Catholic University Leuven hypothesized that caffeine might increase the absorption of creatine by the muscle cells and consequently could lead to a higher creatine concentration in these cells. They actually had a good reason to think this. Creatine transport through the cell membrane is facilitated by sodium-dependent transporters. Sodium can be found in the cells in a low concentration and a high concentration outside the cells. This gives sodium the ‘tendency’ to flow into the cells and your cell can extract energy from this current. To grasp this, think of a real world dam. If you have water on one side of the dam at a higher level than the other side, the water ‘wants’ to flow down and you can extract energy from this. Since cells require energy to take up creatine, they have to get it from somewhere. And in this case, cells extract the energy from the ‘downhill’ sodium gradient: from outside the cell, to inside the cell. Basically, the larger the gradient, the better the creatine transporter might work. So what has caffeine to do with all of this? Caffeine stimulates sodium-potassium pump activity . Sodium-potassium pumps utilize ATP to pump sodium out of the cells, and pump potassium into the cells. So when these pumps pump a little harder, the sodium concentration gradient can increase.
So in a nutshell:
Caffeine-> increased sodium-potassium pump activity -> increased creatine transport activity -> more creatine in your muscle cells -> $$$ gains
This same line of thinking is behind the story of creatine taken together with an insulinogenic meal, as insulin also stimulates sodium-potassium pump activity.
In order to test their hypothesis, the researchers recruited nine healthy young men. These were then randomly assigned to one of three groups. A placebo group, a creatine group or a creatine + caffeine group. The placebo group got a placebo (glucose) for six days, the creatine group received creatine (0.5 g/kg bw per day) for six days, and the creatine + caffeine group received the same amount of creatine with an added 5 mg/kg bw caffeine for the final three days of the six day period. After the last day of the experiment, a muscle biopsy was taken to assess intramuscular ATP and creatine phosphate concentrations and the men also had to undertake a physical test. The physical test included three consecutive maximal isometric contractions (knee extensions) of three interval series of 90, 80 and 50 maximal voluntary contractions performed with a rest interval of 2 minutes between the series. And they determined dynamic torque. And since it was a crossover trial, there was a wash-out period of three weeks in total after which the men were assigned new groups, etc. Although the wash-out period seems a little bit too short, the data in the study does not appear to indicate this being a problem.
Anyways. What did they find? 1) There was no significant difference in intracellular creatine phosphate concentration between the creatine and creatine + caffeine group, and 2) there was a significant increase in dynamic torque in the creatine group vs. the placebo group, but not in the creatine + caffeine group. Holy shit. How can that be? Well, some years later, Hespel and his co-workers, also from the Catholic University Leuven, came with a possible answer. Creatine and caffeine might have a counteracting effect on the relaxation time of the muscle. When you activate a muscle, a signal is conducted by a motor neuron to the muscle cell. This depolarizes the muscle cell which leads to a fuck load of calcium flowing out of a cell organelle called the sarcoplasmic reticulum into the cell. This increase in the intracellular calcium concentration is what makes your muscle contract. When there isn’t a new signal coming from the motor neuron to depolarize the cell and start this cycle, the sarcoplasmic reticulum will suck up all this calcium again so the muscle relaxes. The time required for this reuptake of the calcium is called the relaxation time. Creatine decreases this  and the combination with caffeine apparently negates this effect .
What was wrong with the first study and why relaxation time is boring
So as I mentioned earlier, the wash-out period of 3 weeks in the study by Vandenberghe et al. can be considered a little too short. Since it can take up to about 6 weeks before the creatine concentration is back to baseline. Consequently, some of the creatine & caffeine lovers criticized the study because of this. However, the researchers also measured the creatine phosphate concentration on day 1 in all three groups, and there were hardly any differences. This makes it unlikely that this has influenced the results of the study. A way bigger issue in my eyes is the following sentence which can be read in the full text:
The last dose of caffeine preceded the measurements on day 8 by at least 20 h.
So the participants got their high-dose of caffeine three days in a row, then didn’t get their happy shot for 20 hours, and then they had to physically perform. Wouldn’t that make everyone feel like rubbish? Symptoms of caffeine withdrawal appear within 12-24 hours, with a peak in fuckery between 20-51 hours . And the badness of these symptomes increases with the amount of caffeine you took before you went cold turkey on your caffeine. With 5 mg/kg bw of caffeine (as in the study) a 80-kg person would take 400 mg. To put that in perspective, withdrawal symptoms can already occur if you took 100 mg per day. In short, the study basically showed that you suck at knee extensions after caffeine withdrawal.
And what about the relaxation times? I cannot be bothered to translate this from the Dutch version, but really? A decrease in relaxation time is the magic behind creatine’s strength-increasing effect? No. Just no. Note that the study with the relaxation times by Hespel et al. also write the following:
It is intriguing that short-term caffeine supplementation (5 mg/kg/day for 3 days before the posttest) but not acute caffeine intake (5 mg/kg bolus 1 h before the posttest) impaired muscle relaxation. The last dose of caffeine during the Caf protocol preceded the experiments by at least 20 h.
So the counteracting effect of caffeine on relaxation time only occurs after you’ve NOT taken your caffeine-dose for 20 hours.
It should therefore come to no surprise that creatine and caffeine, when put into a multi-ingredient supplement, or when taken with caffeine-holding beverages such as coffee or tea, has shown ergogenic effects over and over again .
In my opinion it is quite simple. You can take creatine and caffeine together. Just make sure your last caffeine dose wasn’t more than 12 hours ago (unless you never take caffeine) or the withdrawal might bite you. So please, enjoy both your creatine and caffeine.
- Vandenberghe, K., et al. “Caffeine counteracts the ergogenic action of muscle creatine loading.” Journal of applied physiology 80.2 (1996): 452-457.
- Lindinger, M. I., R. G. Willmets, and T. J. Hawke. “Stimulation of Na+, K+‐pump activity in skeletal muscle by methylxanthines: evidence and proposed mechanisms.” Acta physiologica scandinavica 156.3 (1996): 347-353.
- Hespel, Peter, B. Op‘t Eijnde, and Marc Van Leemputte. “Opposite actions of caffeine and creatine on muscle relaxation time in humans.” Journal of Applied Physiology 92.2 (2002): 513-518
- Van Leemputte, Marc, K. Vandenberghe, and Peter Hespel. “Shortening of muscle relaxation time after creatine loading.” Journal of Applied Physiology 86.3 (1999): 840-844.
- Juliano, Laura M., and Roland R. Griffiths. “A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features.” Psychopharmacology 176.1 (2004): 1-29.
- Trexler, E. T., and A. E. Smith-Ryan. “Creatine and Caffeine: Considerations for Concurrent Supplementation.” International journal of sport nutrition and exercise metabolism (2015).