Caffeine needs little introduction; it is a stimulant, is widely consumed (by ~90% of the population), and can enhance sports performance. This short blog post will cover the ‘need to know’ regarding caffeine for sports performance.
After consumption, caffeine reaches a peak in the body after 30 – 60 minutes. It has a ‘half-life’ of somewhere around 3 – 5 hours (meaning that half the amount of the ‘peak’ level is still in your system that many hours later). Additional intake on top of this is ‘additive’ (in that the level will keep increasing). Caffeine is absorbed a little better as a tablet or powder, than it is in coffee. In addition, it may also be better absorbed as caffeine chewing gum than as a tablet/in powder form.
How does it work? caffeine primarily promotes performance improvement via central nervous system stimulation. It blocks adenosine, which would otherwise serve to decrease arousal and alertness (due to inhibiting the release of brain excitatory neurotransmitters, especially dopamine).
Problems with research: caffeine is one of the most researched sport performance supplements. However, there are some research issues to bear in mind. Many studies have used small sample sizes (of less than 15 individuals) and some have used untrained individuals (who often demonstrate the greatest response to consumption, compared to well-trained individuals). In addition, fixed doses of caffeine are often prescribed (as opposed to a dosing strategy ‘tailored’ to perhaps better suit the individual). For example doses such as 100mg, or 200mg or 400mg are given, as opposed to using doses such as: 3mg per kg of bodyweight, or 6mg per kg of bodyweight. (As a reference, 3 miligrams per Kilogram of bodyweight would necessitate 240mg of caffeine for an 80Kg athlete – see below). Lastly, some people may experience hypersensitivity to consumption, so it’s importance to know one’s individuality. (If you do experience hypersensitivity to caffeine, L-Theanine may help to counteract this).
Action: 80Kg athlete, taking 3mg/Kg Bw = 240mg caffeine 45 minutes prior to performance. See HERE for caffeine tablets.
Caffeine most probably has it’s best effects in endurance-based sports lasting between 30 and 90 minutes. This would apply to running, as well as team sports like football and rugby. Studies replicating endurance performance show an increased time to exhaustion, a decrease in fatigue and an increase in performance. It is possible that caffeine can increase someone’s sprint performance and strength, although results findings are mixed. The same goes for multiple sprint performance events, where perhaps more studies are required.
In summary: where exercise or sport performance lasts between 5 and 120+ mins, a dose of caffeine between 3 & 6 mg per kg of bodyweight would appear one of the only supplements worth taking that will significantly improve performance (anywhere from 1 – 5%). Sports where caffeine consumption is probably beneficial would include: football, rugby, 10Km, half- and full-marathons, 50 mile Time trial cycle rides, and perhaps some others. Take this 30 minutes prior to commencing performance, and consume this as a powder/tablet/chewing gum for best effects. (See HERE for more information on caffeine chewing gum).