Caffeine is the most used psychoactive drug In the world. In fact an average Australian consumes 3mg/kg of caffeine per day (1). Caffeine and athletes are like swimmers and chlorine, they can’t go for long periods without each other. I have a question on my initial consult form that asks “ is there any food you cannot live without?” And almost all my endurance clients write a funny comment about coffee next to it. Caffeine is the drug we get up for, the reason we ride and the dietary staple that no matter what any new research tells us, we are all never giving up. But what are the actual facts about caffeine and can this legal drug be a performance enhancement or perhaps assist in our recovery?
Caffeine for performance
Caffeine is a naturally occurring stimulant found in nuts, seeds and leaves. Caffeine is mainly associated with coffee, however it is also found in Coca Cola, tea, sports drinks and supplements, energy drinks and chocolate.
The main benefit of caffeine consumption is its effects on the central nervous system and reduced perception of effort or fatigue. This means that when we have a certain dose of caffeine we may prolong our time to fatigue and hence go harder for longer. Exactly what we are trying to do when racing endurance events.
Caffeines effect on the central nervous system and its effectiveness on enhancing sport performance is seen at doses between 3-6 mg/kg. A standard coffee contains around 120mg of caffeine and therefore a double shot of coffee would be required for a 70kg person to see a performance enhancement (2). Often when we are told we need at least 3mg/kg of caffeine to enhance performance our A type personalities go, “I’m going to have 5 times as much then I’ll have an even greater performance enhancement”. Hold onto your, 'more is better’ vibes, as there is no benefits in having more than 9mg/kg of caffeine to improve performance (2).
Caffeine is ergogenic for sustained maximal endurance exercise such as triathlons, marathons, endurance swimming and any efforts that have a time trial factor (4). Interestingly caffeine has a greater ergogenic effect when consumed in a supplement form compared to having it in coffee (3). This shines a light on the benefits of caffeine in sports nutrition gels such as; Clif Bar Double Espresso with caffeine, Maurten Gel 100 Caf 100, SIS Go Energy + Caffeine Gels and Neversecond C30 Energy Gels Cola with caffeine and Espresso with caffeine.
Caffeine combined with carbohydrates has been proven to have no significant enhancement on exercise performance (6). Therefore there is no need to have a strategic race day plan that combines caffeine and carbs for a performance benefit.
Caffeine and fat oxidation
Caffeines performance enhancement was originally thought to be that it increases intramuscular fat oxidation during exercise and spared glycogen (5). Probably a big contributing factor to its popularity in the sporting community. However once again we are reminded that this metabolic energy change is within the muscles and does not correlate to a reduction in overall fat loss.
Although caffeine may act to increase performance by altering substrate utilisation this doesn’t mean it necessarily increases performance or enhances overall fat loss.
Caffeine for recovery
More recently caffeine has been seen as a hero assisting recovery when partners with carbohydrates post workout. The combination of carbs and caffeine has been proven to increase the rate of glycogen synthesis post exercise (7, 8). In simple terms this means help replace the stored carbohydrates in our liver and muscles that we have just used up while exercising. So having Tailwind Nutrition Recovery Mix straight after training may actually assist muscle glycogen synthesis by up to 66% within 4 hours of finishing training (8).
Caffeine has a half life of 3-6 hours in the bloodstream which means its takes this long to clear out of your system. An important fact worth noting if you are having caffeine in the late afternoon and consumption is within 3-6 hours of your bedtime. Sleep is one of the best tools for recovery and therefore consuming caffeine and stimulating the nervous system before bed can negatively impact recovery.
Can caffeine make me dehydrated?
Caffeine consumption actually does induce an acute state of dehydration. However having caffeine supplement and having caffeine in drinks present two varying scenario’s. When we have caffeine in our a drink form like Fixx Nutrition - Cold Brew Coffee Shot we are also consuming liquid, I.e. water. Therefore the diuretic effect of the caffeine may be cancelled out by the water consumed in the drink.
Furthermore while caffeine may induce acute dehydration the scientific literature does not support caffeine-induced diuresis during exercise, or any harmful change in fluid balance or blood plasma volume that would negatively affect performance (2). This means that it is unlikely that having caffeine in supplement to drink form up to 6mg/kg will effect endurance performance or hydration status (9). It is worth noting most of these studies are done on males and females with varying hormonal phases my react differently, an area that has little evidence thus far.
Summary
Caffeine supplementation can enhance sport performance however this is dependent upon a number of factors such as; the condition of the athlete, exercise and dose of caffeine. If you enjoy your caffeinated gels, hydration or recovery mixes during after training you are likely to be getting some small benefits in perceived effort of training and replenishment of glycogen stores after training.
It is imperative to remember however that each individual responds differently to caffeine dosages whether as a performance enhancement or recovery tool. There may be more variability in females response to caffeine as again many studies are done on males so results may be skewed for females.
Caffeine Per Gel
30mg of Caffeine- Pure Sports Nutrition [Espresso with caffeine]
75mg of Caffeine- Neversecond - C30+ Energy Gels [Cola with caffeine and Espresso with caffeine]
100mg of Caffeine- Clif Bar - Shot Energy Gel [Double Espresso with caffeine]
80mg of Caffeine- Koda Nutrition [Cappuccino with caffeine]
100mg of Caffeine- Maurten - Gel [100 Caf 100]
75mg of Caffeine- Science In Sport [Go Energy + Caffeine Gels]
References
Alcohol and drug foundation, Caffeine (2020). Victoria. Available from; https://adf.org.au/drug/facts/caffeine/#:~:text=The%20average%20intake%20of%20caffeine,2.6%20standard%20250mL%20energy%20drinks).
Goldstein, E.R., Ziegenfuss, T., Kalman, D. et al. International society of sports nutrition position stand: caffeine and performance. J Int Soc Sports Nutr 7, 5 (2010). https://doi.org/10.1186/1550-2783-7-5
McArdle WD, Katch FI, Katch VL: Exercise physiology. Energy, nutrition, & human performance. 2007, Baltimore Lippincott, Williams & Wilkins, (Series Editor)
Fredholm BB, Battig K, Holmen J, Nehlig A, Zvartau EE: Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev. 1999, 51: 83-133.
Spriet LL, MacLean DA, Dyck DJ, Hultman E, Cederblad G, Graham TE: Caffeine ingestion and muscle metabolism during prolonged exercise in humans. Am J Physiol. 1992, 262: E891-8.
Jacobson TL, Febbraio MA, Arkinstall MJ, Hawley JA: Effect of caffeine co-ingested with carbohydrate or fat on metabolism and performance in endurance-trained men. Exp Physiol. 2001, 86: 137-44. 10.1113/eph8602072.
Battram DS, Shearer J, Robinson D, Graham TE: Caffeine ingestion does not impede the resynthesis of proglycogen and macroglycogen after prolonged exercise and carbohydrate supplementation in humans. J Appl Physiol. 2004, 96: 943-950. 10.1152/japplphysiol.00745.2003.
Pedersen DJ, Lessard SJ, Coffey VG, Churchley EG, Wootton AM, Ng T, Watt MJ, Hawley JA: High rate of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine. J Appl Physiol. 2008, 105: 7-13. 10.1152/japplphysiol.01121.2007.
Del Coso J, Estevez E, Mora-Rodriguez R: Caffeine during exercise in the heat: Thermoregulation and fluid-electrolyte balance. Med Sci Sports Exerc. 2009, 41: 164-73.
Ashley Thomas
Masters in Nutrition and Dietetics
Bachelor of Physical and Health Education
