Performance nutritionist Dr Kevin Currell brings together the latest caffeine research to give you a performance edge.

Caffeine is one of the few supplements that has been shown to improve performance over a variety of distances. In general you can expect it to give you an improvement of around two to three per cent. Despite the benefits, there is still confusion about how to use it properly and why it works. In worst-case scenarios it can leave you feeling nauseous, nervous and sleep starved.

How Caffeine Works

There are lots of different theories as to how caffeine might improve performance, and some are more convincing than others.

Theory 1. Caffeine spares muscle glycogen during exercise by promoting fat usage.
It is clear that caffeine has very little effect on metabolism and will not promote fat usage or help you lose weight.

Theory 2. Caffeine enhances carbohydrate absorption.
Research has suggested that adding caffeine to your carbohydrate source during exercise may aid its absorption, but this is far from conclusive.

Theory 3. Caffeine stimulates your brain.
Caffeine seems to talk to the brain to alter the sensation of pain and effort you feel during exercise. It works by making exercise feel ‘less painful’.

How Caffeine Can Make You Faster

It is a fact that caffeine can positively enhance your training and racing performance, especially in situations
like these:

Early morning training
Recent research has shown that taking caffeine when in a sleep-deprived state improves performance and allows you to make better decisions and execute skills. If you have a strong coffee 30 to 60 minutes before an early swim it may help you train more effectively. Only about one 1mg of caffeine per kilogram of body weight is needed to benefit.

Prior to high intensity training sessions
Caffeine has research proven benefits for athletes exercising at high intensities. Therefore, it makes sense to use a dose of caffeine about an hour before a tough session such as run reps. Again aim for 1mg of caffeine per kilogram of body weight. This will help you to exercise harder and faster, enabling you to maximise your workout.

Sprint and Olympic- distance triathlons
To boost your race-day performance, take 1-2mg of caffeine per kilogram body weight an hour before your race. I would also recommend a strong coffee three to four hours before your race too. During the bike leg of the race I aim to take 50-100mg of caffeine in the form of gels and drinks.

Long-distance triathlons
There is less research in this area, but there is evidence to suggest taking caffeine late in exercise when you are already fatigued will improve performance. I would recommend taking 1mg/kg body weight of caffeine in the morning to enhance skill performance during the swim. Then wait until the second half of the bike before taking any more. At this point start to take 50mg per hour for the rest of the bike and throughout the run. Flat cola works perfectly on the run but be sure not to overdo it, as you may upset your stomach

This article was originally published in Triathlon Plus magazine. Save time and money by having every issue delivered to your door or digital device by subscribing to the print edition or buying digitally through Zinio or Apple Newsstand.

You’ll find loads more triathlon training advice in’s Training Zone section.

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