Caffeine to enhance performance

Caffeine has been recognised for hundreds of years for its ability to enhance performance and is commonly used by amateur and professional athletes today (professional athletes can use a certain amount of caffeine until it is deemed as doping – it’s the equivalent of about 8 cups of brewed coffee).

But does it really increase performance?


How does it work? Are there any side effects? Let’s see what the evidence actually says….

Caffeine is the most commonly used drug in the world and is used regularly by most of the UK population in the form of coffee, tea, coke, chocolate and some drugs.

Caffeine and performance

The majority of research that has been done about caffeine intake has shown that caffeine increases performance (specifically the time it takes to fatigue) in longer exercise bouts (30-120mins).

The research for shorter bouts of exercise are a little less clear – some researchers have found that it increases performance and some researchers have found that it has no effect (there have little/no studies that have found that it decreases performance).

Interestingly it seems that more is not nessasily better when taking caffeine.

The majority of studies have found that smaller intakes (3-6mg per kilo) have the same benefits as larger doses (up to 12mg/kg).

Caffeine is a substance that your body can build a tolerance to

 I’m sure we all know someone who can drink coffee all day without it affecting them as it might somebody else. The time it takes for the body to build up a tolerance to caffeine is really quick – you can build up a tolerance in as little as 3 days.

But, most of the literature has shown that doses of caffeine have similar effects for habitual and non-habitual users, so the actual performance benefit would be the same if you’re a regular caffeine taker or not.

Caffeine has also been shown to reduce tiredness and as a result people perceive that they’re not working as hard compared to people who have not had caffeine, which can make them work harder, which will result in a further increase in performance.

How long does it take to work?

Peak blood concentrations are after 30-60 minutes after ingestion but the effects can last for up to 12 hours.

So the best advice at the moment is to take caffeine about an hour before exercise.

Interestingly, smoking speeds up caffeine clearance from the body (due to smoking increasing the activity of the liver cytochrome P450, which metabolises caffeine), however the effect of the nicotine are similar to caffeine so you’d probably feel the same.

caffeine exercise performance_2Is it all about coffee?

Maybe not..some studies have shown that taking caffeine as a pill can give better performance results than drinking coffee, however this is still under debate.

Fat burning

Caffeine has been reported in the media recently about its ability to reduce fat stores in the body (many sports brands are currently reporting this too and using it as a tool to sell their caffeine added drinks/gels).

But what is the truth about fat burning and caffeine?

The answer is – we simply don’t know for sure (sorry for the indefinite answer!). However there is a theory which is generating some momentum at the moment which concludes that caffeine can help with utilising fat stores, basically when you ingest caffeine it causes the release of fatty acids from the fat into the blood, where it can be used as a fuel source.

This theory also suggests a physiological reason why you would have an increase in performance – whilst you are using fat then you are saving the energy stored in your muscles for later, so you can go for longer before you become fatigued.

One interesting question about this theory is – where does the fat go if it is not all used whilst exercising (ie. You don’t do enough cardio exercise to use all of the fat that has been released into the blood steam).

The answer to this is that it goes straight back to where it came from – the body. So using this theory, using caffeine alone won’t help you lose fat (if it did we wouldn’t have so many overweight people in the world!).

Side effects

There are a few potential side effects when using caffeine:

– Caffeine also produces an increase in the activity of your bowels, meaning that everything down there is essentially sped up! It also produces an increase in the production of acid in the stomach, meaning that if you are prone to things like acid reflux and/or heartburn it may be uncomfortable and make these things worse.

– People have also reported headaches and stomach cramps as a result of having caffeine, so all of these things need to be taken into consideration when thinking about taking caffeine before exercise.

‘Caffeine makes you dehydrated’ This is an urban myth (similar to the myth that alcohol dehydrates you) – there is no evidence to support this at all.

There have been many studies that show caffeine does not negatively affect hydration status in resting and in exercise.

The bottom line

Using caffeine during a longer (more than 30 minutes) exercise bout is likely to increase your performance, but could have some unpleasant side effects.

It could also increase the chance of using fat as a fuel source, which could lead to fat loss, although this is under debate.

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