Caffeine has been widely proven as a means of enhancing exercise performance and is used as a pre-workout by many athletes. At the same time, it offers its benefits on a universal level, maintaining primacy in preference as everyday drink of energy, concentration, mental and physical alertness.
The first known study on the subject was published in 1907. Since then a wealth of research has approached the “magic” chemical compound that has a wide range of ergogenic effects1 as it increases:
- muscular endurance
- muscle strength
- anaerobic power
- aerobic endurance
The data converge that the magnitude of the effect of caffeine is probably greater for aerobic exercise compared to anaerobic exercise.
“How much caffeine is necessary for optimal athletic performance?”
Current guidelines recommend intake of 3-9 mg caffeine/kg body weight approximately 60 minutes prior to exercise 2,1.
The “average” cup of coffee contains about 100 mg of caffeine. So as a general rule of thumb, 2 cups of coffee (200 mg of caffeine), consumed about 60 minutes before exercise, should have an ergogenic effect on most people.
However, the effect varies considerably between individuals, with responses ranging from highly ergogenic to the other extreme, i.e. ergolytic.
What factors are involved in the personalized response?
Genes
Differences in response between individuals seem to be mediated by genetic predisposition, as well as environmental factors that have evolutionarily influenced DNA 2,3. The main genes that seem to be involved are those that affect the speed of caffeine metabolism and the excitability of the nervous system. Genetic differences cannot explain all the variation in the effect spectrum, but they can at least explain some of it.
Sleep and Anxiety
Sleep disturbances have been observed after caffeine ingestion3 and therefore the time of consumption is important. It is recommended to consume less caffeine before an evening race compared to a morning one. Also, consumption should be controlled when a race is approaching, where reduced recovery and insufficient sleep can affect final performance.
The beneficial effect of caffeine in fatigue conditions could, with appropriate planning of consumption, contribute to the management of jet lag and the time difference when the athlete competes in another country4.
Some athletes experience greater anxiety when consuming caffeine3. In this case, it makes sense to moderate the intake before high-profile matches.
Sex
Comparisons between men and women report similar effects of caffeine in both sexes. However, there were significant differences in post-exercise caffeine concentrations, with women having a greater amount. This suggests that women do not metabolize caffeine as quickly as men, so they may be able to benefit for a longer period of time after consuming caffeine.
In conclusion, there is a need to develop individualized guidelines on caffeine intake. Further science study could clarify issues where research conclusions remain conflicting.
- Grgic J, Grgic I, Pickering C, et al Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analysesBritish Journal of Sports Medicine 2020;54:681-688.
- Pickering C, Kiely J. Are the Current Guidelines on Caffeine Use in Sport Optimal for Everyone? Inter-individual Variation in Caffeine Ergogenicity, and a Move Towards Personalised Sports Nutrition. Sports Med. 2018 Jan;48(1):7-16. doi: 10.1007/s40279-017-0776-1. PMID: 28853006; PMCID: PMC5752738.
- Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021 Jan 2;18(1):1. doi: 10.1186/s12970-020-00383-4. PMID: 33388079; PMCID: PMC7777221.
- Pickering, C., Grgic, J. Caffeine and Exercise: What Next?. Sports Med 49, 1007–1030 (2019). https://doi.org/10.1007/s40279-019-01101-0
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