Caffeine dosage for performance
As can be seen from all of these results, the effect of caffeine on each person is highly individual, and is largely mediated by our genes. Specifically, the gene that codes for the CYP1A2 enzyme – I know, catchy name! Essentially that gene means we either break down caffeine really quickly, so we need a higher dose to have an effect, or it takes ages to break the caffeine down so we need a much lower dose for a large effect. This video explains it all really neatly.
Caffeine doses, timing and how to take it
The doses of caffeine used in these trials all range from 3-6mg per kilo of the athlete’s weight. There doesn’t seem to be any performance benefit of going above 9mgs per kg, but there are potentially quite a few drawbacks including heightened anxiety, gastro-intestinal issues and a rapid, potentially irregular heartbeat.
For a 70kg athlete, 3-6mg per kilo of the athlete’s weight would be 210mgs – 420mgs, which equates to roughly 2.5-5 shots of espresso. However, the amount of caffeine in coffee can vary dramatically, even if you get the coffee from the same place and order the same thing each day. Therefore it’s probably not the most reliable source of pre-training caffeine if you want to be precise about it!
Coffee also comes with its own drawbacks, in that it contains a whole load of other compounds besides the caffeine and can potentially be quite irritating to the gut. Combine that with competition day nerves … and an athlete may find themselves more than a little distracted!
Logistically, it can be a bit of a nightmare for athletes to make sure they find and can consume the coffee at the right moment, and as coffee is usually something we have hot, it’s not always great for summer competitions or trying to drink quickly during a warm-up.
More reliable, easier-to-take sources of caffeine include anhydrous tablets, caffeine chewing gum, pre-workout shots, energy drinks and caffeine in gels and energy bars. Caffeine can also be taken as mouth rinses and nasal sprays, but the jury is still out as to whether they are as effective. However, as with any supplement, it’s the dose that makes the poison, so athletes need to be careful they are getting the right overall dose – especially if they’re combining different sources.
General guidelines for caffeine suggest taking it about 60 minutes before exercise, as it needs to be digested, absorbed, and pass through the liver before it can start to have an effect on the central nervous system. It usually takes about 20-30 minutes before the effects are noticeable, and about 60 minutes before the blood concentration reaches its peak. Chewing gum tends to be absorbed faster, as it doesn’t need to be digested through the stomach and is instead absorbed through the membranes in the mouth, as described in this article.
Which form of caffeine is best for each athlete can vary enormously, and comes down to things like:
- Is it easily available at the competition, or in the country where the athlete is competing?
- Is it easy to travel with? Liquids can get heavy if an athlete is away for several back-to-back competitions.
- If the athlete is travelling with hand luggage only, can it be taken on the plane?
- Does it contain any other ergogenic aids which the athlete may also be taking separately?
- Is it cost effective?
- When will the athlete have time to take it before the competition in relation to pre-competition commitments?
- Does the athlete have access to their bag 60 minutes before competition, or is it away in a locker room? In which case would they need to have it in a pocket or similar?
- Is it Informed Sport tested?