Former professional road cyclist and Sports Performance Nutrition lecturer Danielle Clay tells us once and for all if caffeine is beneficial for athletic performance.

There’s a lot of research surrounding the pros and cons of caffeine for both sprint and endurance athletes. A quick Google search will result in a plethora of conflicting opinions which can be frustrating when you are trying to optimise your training and event diet to ensure you maximise performance.

So, in a bid to settle the debate once and for all, we’ve enlisted the help of Danielle Clay, a former professional road cyclist, who now lectures in Sports Performance Nutrition at Leeds Trinity University.

Here she shares her views on how caffeine can benefit athletic performance, how much you should take and when you should take caffeine on board.

What effects does caffeine have during exercise?

1. Caffeine will kick start your fight or flight:

“Caffeine makes you feel more alert, less tired and it’s also been proven to influence pain perception too. Your adrenaline and cortisone levels which are the stress hormones involved in fight or flight will increase when you take caffeine – this helps with both muscle contraction and pain perception. The increased muscle contraction will benefit every kind of athlete from downhillers to gym-goers and endurance athletes.”

2. Caffeine will keep you going for longer:

“We believe this primarily because caffeine helps to burn fat which in turn will save some of your glycogen stores. At the end of the race, when you need it the most, you will then have some carbohydrate left in reserve to get you to the finish line.”

How much caffeine should we take?

“The amount of caffeine you should take on board is a very individual thing. If you are a habitual coffee drinker then you are going to need more caffeine to stimulate you. I would normally recommend that most athletes try and abstain from consuming caffeine habitually if they want to use it for performance because your body does adapt to having a chronic intake of caffeine.

“I would usually recommend that people take on board 1-3mg of caffeine per kilo of body weight. So if you are 80kgs a can of Red Bull is about right as it contains 80mg of caffeine. Some people will need more as it really depends on how your body reacts to caffeine, how it metabolises it and how much you drink habitually day-to-day. We would tailor the amount of caffeine recommended to the specific athlete based on these variables.”

When is the best time to take caffeine on board?

“Caffeine seems to peak about two hours after it is ingested if it is taken in the form of a drink. Now that doesn’t mean that it won’t have effects much sooner but that peak effect is actually quite delayed.

“It goes through various stages of breakdown in the liver and some of the later stages can actually be as potent as the original caffeine stage. So, if you are using it for events you need to ingest it about one to two hours before your start time. Again, this differs from person to person. Some people find that two hours is too long and they feel a little bit too wired too early on, so you have to experiment a little bit with it.

“You have to be a little more careful with endurance events. You want a more sustained effect so you will need to take on smaller amounts more regularly. You might drip feed the system every hour so that will give you glycogen storing effect but also a small stimulant effect regularly through your event.”

Is there such thing as too much caffeine?

“Taking on too much caffeine can be really detrimental to performance as you will produce too many of those stress hormones we were talking about and this can actually deplete your energy stores. Those doing endurance events need to be especially wary of this, it is all about drip feeding the system from early on in this case.”


“I cannot stress enough that everyone is different. Try to experiment and see what works for you.”

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By Outsider

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