The daily fix or the ergogenic aid?
The morning brew is pretty damn important to some of us. There is not much better than a well crafted cafe to start the slog. For the day-to-day man it makes the commute bearable and the first few emails a breeze, but there is also good evidence that caffeine is both safe and possibly beneficial for performance in athletes.
Caffeine is a stimulant. That is why we crave it and why it makes the morning more pleasant. It also changes your perception of events and one important perception is that of effort. Not only does that mean we can get through the morning with minimal fuss but this is also why it assists athletes perform harder, changing their perception from “are you crazy?” to “one more rep”. The most promising results shown in most research is that of improvements in endurance performance but the benefit also extends to other mixed-type events (team sports) as well as short, high intensity sports (middle distance events) lasting 1-60 minutes too. There does not appear to be any benefit for strength and power events however.
To summarise a review article by Louise Burke:
- the mechanism of action is poorly understood
- caffeine enhances endurance performance over a range of protocols
- caffeine can be ingested before or during exercise or after the onset of fatigue
- benefits occur at 1-3 mg/kg body weight with little or no dose-response relationship
- some people are non-responders
- withdrawing from caffeine to maximise its effect may occur over 24-48 hours but this effect is unproven
- dosages as high as 6-9 g/kg body weight may have adverse effects
- the effect of caffeine may last up to 6 hours with individual variances
Caffeine was previously a banned substance but has since been removed from the World Anti Doping Agency (WADA) list. This decision was taken due to caffeine being a commonly consumed compound in a regular diet and the fact that it has no adverse health effects at normal doses. However high doses of caffeine (10 mg/kg body weight) can cause adverse effects such as heart palpitations, diarrhea and cramping, particularly to those who are sensitive to the stuff. Adults who do not consume caffeine in their diet should not aim to use caffeine as a supplement and anyone under the age of 16 should avoid excess dietary intake of caffeine.
While a dose-response is small it seems as though the performance benefit of caffeine plateaus at around 3 mg/kg and a safe recommendation is thus 1-3 mg/kg, split it into a pre-exercise and mid-exercise dose. For a 70 kg athlete this would be around 70 mg before exercise and 70 mg toward the point where you know things get difficult.
We do also get responders and non-responders to caffeine supplementation which means that it might not work for everyone. At these dosages, however, it is safe to try and see the effects for yourself. Make sure you try it in training first though, not at 6h30 on the morning of the Argus.
The jury is still out on the effect caffeine might have on recovery from exercise. The concern here is the link to sleep deprivation, dehydration and altered glucose metabolism that are all important aspects of recovery and impact glycogen replenishment in the muscles. Research does suggest that altered sleep quality is linked to the responder and non-responder issue and the dehydration and altered glucose metabolism may be less of an issue than first thought.
Coffee, or most foods for that matter, are not a great way of supplementing as the values vary greatly but food sources are a safer bet than commercial products in terms of safety for athletes. Some products like gels and bars from Gu or Hammer have caffeine added and listed. The good old “Regmaker” is a caffeine pill that provides 150 mg per serving.
Common sources of caffeine are listed below.
|Food/Beverage||Serving size||Caffeine content (mg)|
|Instant coffee||250 ml||60 (may be 15-150mg)|
|Brewed coffee||250 ml||80 (may be 40-110mg)|
|Espresso||35ml||110 (may be 25-210mg)|
|Tea||250ml||30 (may be 10-50mg)|
|Scheckters Energy Drink*||250ml||85|
|GU sports gel||32g sachet||20|
*Scheckters Energy Drink is Informed Choice approved and safe for use by athletes
For more on the safety and efficacy of supplements READ HERE. Consult your health practitioner or specialist before using any supplement.