How Coffee Makes You Run Faster
The benefits of caffeine for sport performance
Caffeine is the most used drug in the world. Caffeine is present in coffee, tea, soda and chocolate but also in plants and seeds. Because caffeine is overly present in our daily foods, the World Anti-Doping Agency decided to remove caffeine from the Prohibited List in 2004, making it a legal drug in sports and an interesting subject for research.
Caffeine is considered to be a central nervous system stimulant and various mechanisms of cell metabolism seem to be stimulated by caffeine [6]. These mechanisms could permit an athlete to train at a greater power output and/or train longer. How does caffeine affect sport performance and could it be useful to ingest caffeine to enhance your own sport performance?
Performance effects
Endurance sports: Caffeine ingestions of 3–6 mg/kg body mass significantly increases the time till exhaustion at supramaximal power output (75–80% of maximal oxygen uptake) compared to a placebo ingestion [2, 3]. Ingesting caffeine 1–3h before exercise seems to have more effect than 6h prior to exercise [2].
Because time to exhaustion isn’t used in any sport event, caffeine effect on time trial performance has also been studied. The mean time trial performance improvement is 3%, as was concluded in a meta-analysis4. Another meta-analysis also showed an bigger improvement in performance in longer time trials in comparison with shorter time trials after caffeine ingestion compared to placebo groups [12].
Sprint performance: Caffeine seems to increase sprint performance in team sports1. However, performance improvement of the Wingate-test (an 30 sec all-out sprint test) are controversial with one meta-analysis showing no effect [1], and another meta-analysis showing significant increase in performance [7]. Improvement in sport-specific sprint performance (swimming 100m, cycling sprint) seems to increase after caffeine ingestion in most studies of a meta-analysis [1].
Resistance training: Caffeine ingestion is likely to increase repetition number [1]. Maximal strength seems to increase after caffeine ingestion, but only small effects have been found [1, 8]. Mean propulsive power and propulsive velocity of bench pressing and squatting significantly increases after caffeine ingestion, with better results when ingesting a higher caffeine dose (3, 6 or 9 mg/kg body mass) [11]. Time to exhaustion at 50% of maximal voluntary contraction increases significantly after caffeine ingestion10.
Research of sprint and resistance performance is controversial. Individual differences seem to be the most common explanation to the different effects found, but differences in protocols, performance duration, muscle groups, doses of caffeine and level of fitness of the subjects can add to the differences as well.
Side effects
Although side effects of caffeine are minimal, they could occur if individuals tolerance is low or a high dose of caffeine is ingested. Side effects are e.g. anxiety, sleep quality decrease, increased urine output, gastrointestinal problems, increased heart rate in rest, or headache).
Caffeine ingestion of 3–6 mg per kg body mass produces minimal side effects, while ingestion of 9mg drastically increases side effects [11].
Influence of habitual caffeine consumption
In the study of Bell and McLellan [2], a significant difference was found between non users and users after acute caffeine ingestion in cycle to exhaustion trials at 80–85% of maximal oxygen uptake. Another study showed no significant difference between low (58mg), moderate (143mg) and high (351mg) habitual users in time trial time after acute caffeine ingestion in comparison with placebo [5]. However, acute caffeine ingestion did not improve performance in the high habitual caffeine ingestion group where low and moderate did improve, while not significant. Caffeine withdrawal of 0, 2 or 4 days showed a little, non-significant difference between days of withdrawal group, with 4 day withdrawal performing a bit better after acute caffeine ingestion at a cycle to exhaustion test at 80–85% VO2max [13].
In conclusion, drinking 1 or 2 cups of coffee a day doesn’t seem to harm the benefits of acute caffeine ingestion. However, quitting drinking coffee a couple days before your match may increase the benefits of acute caffeine ingestion.
Types of ingestion
Ingestion of 3–6 mg/kg body mass for an average person is equivalent to 4 to 8 cups of coffee. Because most people will have a hard time drinking so much coffee, caffeine pills of chewing gum are also available. Good news: there seems to be no difference in performance effects between ways of ingesting caffeine [9].
Individual differences
In most of the analyzed studies, performance effects differ between subjects in a big range: some participants show significant improvement , while others show no improvement or even a decline. Explanation of these different results given by the authors of these studies mostly come down to individual differences in response to caffeine ingestion. Side effects are also reported to be different among individuals [11]. Due to these individual differences, it is suggested to experiment with caffeine doses and timing of ingestion in training, before using caffeine in a match.
In short
- For optimal effect, a caffeine dose of 3–6mg/kg body mass should be ingested 1–3h before performance.
- Most studies show an improvement in endurance performance and resistance training performance after ingesting caffeine, while effects on sprint performance are controversial.
- Ingestion too much caffeine will lead to side effects, so trying a caffeine ingestion in training before using it in a match is suggested.
- Effects of acute caffeine ingestion prior to exercise isn’t much different between habitual caffeine drinkers and non-drinkers. However, quitting caffeine a couple of days before performance could help.
- The way caffeine is ingested doesn’t change the performance effects.
- Participants in the analyzed studies show big individual differences in performance and side effects after caffeine ingestion. Experimenting with caffeine dose and timing in trainings is really important in order to get the best effects in match.
References
1. Astorino, T.A. and D.W. Roberson, Efficacy of acute caffeine ingestion for short-term high-intensity exercise performance: a systematic review. J Strength Cond Res, 2010. 24(1): p. 257–65.
2. Bell, D.G. and T.M. McLellan, Exercise endurance 1, 3, and 6 h after caffeine ingestion in caffeine users and nonusers. J Appl Physiol (1985), 2002. 93(4): p. 1227–34.
3. Desbrow, B., et al., The effects of different doses of caffeine on endurance cycling time trial performance. J Sports Sci, 2012. 30(2): p. 115–20.
4. Ganio, M.S., et al., Effect of caffeine on sport-specific endurance performance: a systematic review. J Strength Cond Res, 2009. 23(1): p. 315–24.
5. Goncalves, L.S., et al., Dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation. J Appl Physiol (1985), 2017. 123(1): p. 213–220.
6. Graham, T.E., Caffeine and exercise: metabolism, endurance and performance. Sports Med, 2001. 31(11): p. 785–807.
7. Grgic, J., Caffeine ingestion enhances Wingate performance: a meta-analysis. Eur J Sport Sci, 2018. 18(2): p. 219–225.
8. Grgic, J., et al., Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. J Int Soc Sports Nutr, 2018. 15: p. 11.
9. Hodgson, A.B., R.K. Randell, and A.E. Jeukendrup, The metabolic and performance effects of caffeine compared to coffee during endurance exercise. PLoS One, 2013. 8(4): p. e59561.
10. Meyers, B.M. and E. Cafarelli, Caffeine increases time to fatigue by maintaining force and not by altering firing rates during submaximal isometric contractions. J Appl Physiol (1985), 2005. 99(3): p. 1056–63.
11. Pallares, J.G., et al., Neuromuscular responses to incremental caffeine doses: performance and side effects. Med Sci Sports Exerc, 2013. 45(11): p. 2184–92.
12. Shen, J.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. J Sci Med Sport, 2019. 22(2): p. 232–238.
13. Van Soeren, M.H. and T.E. Graham, Effect of caffeine on metabolism, exercise endurance, and catecholamine responses after withdrawal. J Appl Physiol (1985), 1998. 85(4): p. 1493–501.
