Caffeine: The Miracle Supplement?

Let's face it - most supplements are overhyped, overpriced and under-researched. However, there are a few that have stood the test of time and have an overwhelming body of scientific evidence to support their efficacy in improving performance, and caffeine is definitely one of them.

While many of us turn to caffeine first thing in the morning in the form of coffee or maybe  an energy drink when we need an afternoon pick-me-up, you may want to consider shifting around some of your caffeine consumption to before your training session. Although we are all familiar with the energy boosting effects of caffeine, it is important to note that there are actual quantifiable improvements in performance associated with the substance as well.

That's right, there is strong evidence showing that the supplementation of caffeine can illicit improvements in muscular strength, power, endurance, and both aerobic and anaerobic performance (1,2,3,4). Not only could caffeine supplementation be beneficial before some type of event or competition, it can also provide benefit in our day to day training. If you are able to lift more weight or do more reps in your training, then theoretically this can lead to faster or larger rates of progress.

Now I don't want to overhype the effects that caffeine has, because we are talking about single percentage point improvements in most people. But better is better, right?

With that being said, it is worth noting that there is variability in response to caffeine supplementation between individuals. Some individuals will see large improvements in performance from small doses, while others see no improvements regardless of how much they take. There are a number of different hypotheses for why this might be true, ranging from genetic variations, to training status, to daily caffeine consumption (4). While the likelihood of being a non-responder to caffeine is low, realize that it is a possibility. 

How much to take and when?

Now that we have established that caffeine can improve performance in most people, it's time to go over how much you should be taking and when you should be taking it. 

Most studies have shown positive benefits associated with doses ranging from 3-6mg/kg of bodyweight (1.36-2.73mg/lb of bodyweight for my U.S. friends). It is important to remember what we discussed earlier about the variability between individuals though. For some people, they could take 3 mg/kg and feel out of control, while others could take 6mg/kg and not feel a thing. Finding the right dose for you might take a little experimentation. The FDA recommends keeping caffeine consumption under 400mg/day for most people, and toxic side effects have been observed with rapid consumption of  1,200mg of caffeine. So I would recommend trying to adhere to those guidelines.

As for when you should consume caffeine, about 60 minutes before training seems like the sweet spot considering about 99% of it is absorbed into the tissues within 45 minutes and has a half life of approximately 5 hours (5).

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Downsides to caffeine?

The first, and arguably the most apparent, downside to caffeine supplementation is the negative impact it can have on sleep. As mentioned earlier, there is a ton of variability between individuals when it comes to the effects of caffeine, but considering it has a half life of around 5 hours it's probably best to try and consume most of your caffeine earlier in the day if possible. 

The second downside to caffeine supplementation is once again largely based on the individual, but there are some folks who experience negative side-effects such as feelings of anxiety, jitteriness, headaches, gastrointestinal issues, and rapid heart rates. However, this appears to be associated with higher doses and can likely be remedied by simply reducing the dose (6).

Another possible downside to caffeine supplementation is it's potential interference with creatine (7). Notice I said potential interference. There is still a lot of research that needs to be done to prove this and provide an exact mechanism. However, if you want to play it safe it may not be a bad idea to take your creatine at a different time than your caffeine.

As with many other substances, many individuals will develop a tolerance to caffeine when it is taken frequently for long periods of time (12). Therefore, it's probably not a bad idea to take a week or so off from caffeine every once in a while in order to re-sensitize yourself.  I don't have any specific recommendations here, but you'll likely notice when you reach the point where you feel like you need higher and higher doses to get the same results. 

Finally, I think it is important to address the issue of caffeine "dehydrating" you. You've likely heard that energy drinks, coffee, or  just caffeine in general will "dehydrate" you. While it is true that caffeine has an acute diuretic effect (makes you pee), the claim that reasonable intakes of caffeine will actually cause you to lose a meaningful amount of fluid to dehydrate you is largely unfounded and has been disproven (8, 9, 10, 11). 

Major Takeaways

• There is a ton of variability between individuals. Find what works for you.
• 3-6mg/kg of bodyweight is likely a good dose for most individuals.
• Consume the caffeine about 60 minutes before training.
• Try and keep total intake < 400mg/day.
• Try and consume most caffeine earlier in the day if possible.
• Take a week off from caffeine use to re-sensitize yourself when you notice a diminishing effect.

Anytime we are discussing supplements it is important to make clear that a supplement is just that...a SUPPLEMENT. It is meant to supplement you. It won't do the work for you, and it will not make up for poor diet, training, or sleep.

However with that being said, caffeine is no doubt one of the better supplements out there. It is cheap, readily available, and proven to work in most individuals. As far as supplements go, caffeine is a great one, and it is one that I indulge in regularly. 

Stay caffeinated my friends.

​-Clayton

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References
1. Grgic, J., Trexler, E.T., Lazinica, B. et al. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. J Int Soc Sports Nutr 15, 11 (2018). https://doi.org/10.1186/s12970-018-0216-0
2. Southward, K., Rutherfurd-Markwick, K.J. & Ali, A. The Effect of Acute Caffeine Ingestion on Endurance Performance: A Systematic Review and Meta–Analysis. Sports Med 48, 1913–1928 (2018). https://doi.org/10.1007/s40279-018-0939-8
3. Shen, Joy G et al. “Establishing a relationship between the effect of caffeine and duration of endurance athletic time trial events: A systematic review and meta-analysis.” Journal of science and medicine in sport vol. 22,2 (2019): 232-238. doi:10.1016/j.jsams.2018.07.022
​4. Guest, N.S., VanDusseldorp, T.A., Nelson, M.T. et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr 18, 1 (2021). https://doi.org/10.1186/s12970-020-00383-4
5. Institute of Medicine (US) Committee on Military Nutrition Research. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington (DC): National Academies Press (US); 2001. 2, Pharmacology of Caffeine. Available from: https://www.ncbi.nlm.nih.gov/books/NBK223808/
6. Pallarés, Jesús G.; Fernández-Elías, Valentín E.; Ortega, Juan F.; Muñoz, Gloria; Muñoz-Guerra, Jesús2; Mora-Rodríguez, Ricardo1 Neuromuscular Responses To Incremental Caffeine Doses, Medicine & Science In Sports & Exercise: November 2013 - Volume 45 - Issue 11 - P 2184-2192 Doi: 10.1249/Mss.0b013e31829a6672
7. Vandenberghe K, Gillis N, Van Leemputte M, Van Hecke P, Vanstapel F, Hespel P. Caffeine counteracts the ergogenic action of muscle creatine loading. J Appl Physiol (1985). 1996 Feb;80(2):452-7. doi: 10.1152/jappl.1996.80.2.452. PMID: 8929583.
​8. Killer SC, Blannin AK, Jeukendrup AE. No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS One. 2014 Jan 9;9(1):e84154. doi: 10.1371/journal.pone.0084154. PMID: 24416202; PMCID: PMC3886980.
​9. Maughan RJ, Griffin J. Caffeine ingestion and fluid balance: a review. J Hum Nutr Diet. 2003 Dec;16(6):411-20. doi: 10.1046/j.1365-277x.2003.00477.x. PMID: 19774754.
10. Seal, Adam D et al. “Coffee with High but Not Low Caffeine Content Augments Fluid and Electrolyte Excretion at Rest.” Frontiers in nutrition vol. 4 40. 18 Aug. 2017, doi:10.3389/fnut.2017.00040
11. Armstrong LE, Casa DJ, Maresh CM, Ganio MS. Caffeine, fluid-electrolyte balance, temperature regulation, and exercise-heat tolerance. Exerc Sport Sci Rev. 2007 Jul;35(3):135-40. doi: 10.1097/jes.0b013e3180a02cc1. PMID: 17620932.
​12. Evans SM, Griffiths RR. Caffeine tolerance and choice in humans. Psychopharmacology (Berl). 1992;108(1-2):51-9. doi: 10.1007/BF02245285. PMID: 1410146.