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When it comes to ergogenic aids for exercise performance caffeine is one of the most common and most effective supplements on the market. Used for years by runners, cyclists and power lifters for its beneficial stimulant properties and one of the supplements on the ISSN list of recommended ergogenic aids there’s little doubt about its effectiveness.

First of all, let’s just define what exactly we mean by an ‘ergogenic aid’. This is how the ISSN describe it:

An ergogenic aid is any training technique, mechanical device, nutritional practice, pharmacological method, or psychological technique that can improve exercise performance capacity and/or enhance training adaptations.

Caffeine is categorised as a ‘thermogenic’ because it’s one of a group of supplements which increase metabolic rate. Caffeine is often used in so-called fat burners for this reason. However, many of these contain very high levels of caffeine which may cause unpleasant side-effects such as heart palpitations. But, if in an energy deficit caffeine ingestion may result in slightly elevated caloric burn to assist weight loss. But, let’s face it, most people consume plenty of caffeine in their daily tea and coffee anyway.

There is however considerable literature to support the use of caffeine to improve exercise performance right down to dosage specific advice for each discipline.

Can caffeine make you go?

If you are an endurance athlete is the use of caffeine likely to help you perform for longer, and it has even been shown to improve power output during a hypo glycolytic state in cyclists. Importantly, though, in this study there was an improvement compared to hypo glycolytic states with no caffeine, but power output was still better when tested with adequate glycogen levels. So, taking on caffeine may help you when you’re flagging but not necessarily more effectively than if you were just drip feeding your carbs to avoid glycogen depletion.

It has been observed that cyclists significantly raised their time to exhaustion by consuming 330mg of caffeine in coffee prior to riding. Other benefits have been shown with lesser amounts too. Trials on runners have been a bit more mixed however.

As a general rule taking a minimum dose of 200mg of caffeine 1-hour before endurance type exercise may produce some improvements in endurance performance and, even small doses show improvements in cognitive function which could be just as beneficial over longer distances as any improvements in power output. So, if you like an Americano before you ride then go for it.

However, it also appears that relatively untrained individuals don’t experience an ergogenic effect from caffeine. This is interesting and could mean that most recreational athletes up to intermediate level probably just need to train more. That’s not a bad thing and it’s not like this should come as a surprise to anyone. If you want to get fitter, improve your fitness. If you are fit and want to improve your performance taking some caffeine may make you train a bit harder and perform a bit longer.

The ISSN recommend 3-9mg of caffeine per kg of bodyweight 30-90 minutes prior to exercise to improve endurance exercise capacity. Work out the level that works best for you, and consider starting at the low end when working that out.

Can caffeine improve performance in strength and power sports?

So, it appears that caffeine does indeed have some pretty good benefits for endurance athletes with the main caffeine induced benefit appearing to be improved glucose tolerance and delaying the onset of fatigue so does this transfer over to the gym floor?

When talking about improvements in strength you must understand that the kind of tests used include a rep max bench press and the wingate test, which assesses peak anaerobic output, usually on a cycle ergometer. So, we’re not talking maximal single rep strength here but muscular endurance and power output.

Caffeine certainly seems to exert benefits for team sports like rugby or field hockey and any form of exercise with anaerobic elements to it. So, although it’s not entirely clear whether taking caffeine will make you lift more weight in a single pull it will almost certainly help you to maybe squeeze out an extra rep or two which is great for increasing volume when training for hypertrophy. It’s also highly likely that caffeine will be great for helping you to smash out a few strong man circuits at the end of your session.

Naturally, because it has a high glycolytic load and heavy anaerobic emphasis CrossFit and caffeine seem like a match made in heaven.

Most of the literature seems to indicate that around 5mg per kg of bodyweight 60 to 30 minutes prior to exercise works best.

How should you take caffeine?

Obviously, most people consume caffeine in the form of coffee and tea or soft drinks like colas and so-called energy drinks. Although coffee and red-bull have been used in some of the research it does appear that anhydrous caffeine is preferred. Anhydrous caffeine is in non-liquid form, either powders or tablets, usually.

Caffeine still delivers performance benefits when consumed in coffee but the dosage is more easily controlled in tablet form. If you are aiming for, say 400mg of caffeine before an event you can easily measure out the dosage using caffeine tablets but the coffee is more difficult to quantify and may even contribute to gastrointestinal discomfort in some.

Endurance sports seem to benefit the most from caffeine ingestion

Many commercial pre-workout supplements, like the dreaded ‘pink drink’ contain very high levels of caffeine and we have all seen that bro at the gym downing one of those in on his way in from the carpark and then chugging down Relentless between sets. This is poor caffeine timing – generally meaning that it ‘kicks in’ during his third or fourth exercise when the heavy work is already done - and could be the reason said bro often seems on the verge of throwing the squat rack across the studio in a caffeine fuelled rage (at least we hope it’s caffeine rage).

Interestingly, where it has always been considered useful to limit habitual caffeine intake if you are looking for ergogenic performance benefits more recent research has shown that this may not be the case, or at least not as significant as previously thought. So, if you like your coffee it does appear that you can drink 2-3 cups per day and still strategically use an anhydrous caffeine supplement to experience the ergogenic effects.

Of course, some people are genetic non-responders and may not feel much benefit at all or just simply be able to tolerate a lot more caffeine than the next athlete, meaning that they might not benefit too much from caffeine use as a sports supplement. Conversely, some people have a slow caffeine metabolism and may feel jittery and wired after only one cup of coffee so it’s important to understand how your body responds to caffeine and act accordingly. If you are sensitive to its effects then you would be best to save your caffeine usage for around training and avoid it the rest of the time, your friends and colleagues (and that squat rack) will thank you for it.


Yes, caffeine is safe for use, is effective for use and makes a significant difference to sporting performance. Endurance sports seem to benefit the most from caffeine ingestion, especially cycle time trials. Exponents of strength and power sports like rugby, crossfit and bodybuilding may experience some benefits but the results are a bit more mixed and require further research.

However, the improvements in power output and muscular endurance seen in time trial performance could well carry over to the athletes training, especially when utilising anaerobic intervals. So, although caffeine may not make you lift more weight it could well make you train harder and squeeze out more volume.

  • For endurance sports 3-9mg per kg of bodyweight 30-90 minutes prior to exercises is recommended.
  • For strength and power sports 3-6mg per kg around 30 minutes prior should do it.

Listen to your own body, although the above amounts are clearly stated in the literature there is nothing saying that you couldn’t get great results on less than that. But do be aware that 9mg/kg seems to be the safe upper limit so don’t exceed that.

Obviously, we sell caffeine tabs and they go great mixed in with your pre-workout drinks.


  1. Goldstein et al. International society of sports nutrition position stand: caffeine and performance. Journal of the International Society of Sports Nutrition20107:5 DOI: 10.1186/1550-2783-7-5
  2. Stephen Layne et al. Caffeine Ingestion and Cycling Power Output in a Low or Normal Muscle Glycogen State. Medicine and science in sports and exercise · February 2013. DOI: 10.1249/MSS.0b013e31828af183
  3. Spriet LL. Exercise and Sport Performance with Low Doses of Caffeine. Sports Medicine (Auckland, N.z). 2014;44(Suppl 2):175-184. doi:10.1007/s40279-014-0257-8.
  4. Clark et al. Coffee and Caffeine Ingestion Have Little Effect on Repeated Sprint Cycling in Relatively Untrained Males. Sports 2016, 4, 45; doi:10.3390/sports4030045
  5. Lívia de Souza Gonçalves et al. Dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation. J Appl Physiol (May 11, 2017). doi:10.1152/japplphysiol.00260.2017

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