Nutrition, Podcast

Caffeine in racing – best practices with Andy Blow | EP#346

 July 11, 2022

By  Bernardo Gonçalves


Andy Blow - That Triathlon Show

Andy Blow is the founder of Precision Fuel & Hydration. He returns to the podcast to discuss the science and practice of using caffeine to enhance endurance performance.

In this Episode you'll learn about:

  • The scientific background of caffeine as an ergogenic aid. 
  • Who should and who should not consider using caffeine in endurance events?
  • How to use caffeine before the start of the event
  • How to use caffeine during the event
  • How the duration of the event impacts caffeine intake - from sprint distance to Ironman and through the extreme of multi-day ultra-endurance events
  • Case studies from some of the top triathletes in the world - what are typical caffeine intakes in half and full distance races?

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Caffeine and its effects on performance

02:39 -

  • When you do an endurance event, you sweat and lose fluid and sodium, and you burn calories mainly in the form of carbohydrates.
  • These points are the crucial levers you need to pull during an endurance event. 
  • However, caffeine ingestion is another parameter that is not crucial but that influences performance.
  • Caffeine is a stimulant that acts on the central nervous system to influence the perception of fatigue and the ability to perform, especially when you are tired. Therefore, it can improve performance, and it is one of the only few ergogenic supplements marketed that has the potential to do it.
  • From a meta-analysis that looked at many different papers, the improvements with caffeine ingestion are around 3 %, which is significant.
  • For elite athletes, a 0.5 % improvement is significant, so it is worth it, as it is a low-risk cost-effective strategy to implement.
  • However, the 3 % improvement does not capture the range. Some people should expect more, but some might not experience an improvement and even negatively affect performance.

Caffeine intake

06:03 -

  • While we recommend carbohydrate ingestion in absolute terms (60-100 g/h), we present recommendations in terms of mg/(kg. body weight).
  • The body's ability to metabolise caffeine depends on your size.
  • 3-6mg/kg is the standard caffeine ingestion recommendation to maximise the effects.
  • Caffeine takes some time to affect the body, and it will depend on the person and the nutrition intake before ingesting caffeine.
  • You start to have caffeine in your system after about 15 minutes, but it will only peak after 45-60 minutes.
  • The half-life of the caffeine in the body (the time it takes the body to metabolise 50 % of the caffeine) is around three hours.
  • And these dynamics will influence the timing when you intake caffeine.
  • For example, I would only ingest caffeine at the end of a race because of the thought you will need a boost when you are tired.
  • However, you might take it too late, and the benefits will cost you when you cross the finish line.
  • The amount of caffeine in coffee will depend much on the type of coffee you drink.
  • You get from 70-100mg of caffeine in a standard coffee. Coca-cola has 10 mg/100mL, so 30 mg in total.
  • Red bull is about 30mg/100mL. 
  • A standard recommendation for athletes is to get a strong coffee one hour before the event, followed by a caffeine gel 15 minutes before the start, giving a dose that allows peak caffeine values in the system at the start. Moreover, giving another dose closer to the start will give you another "boost" after one hour of racing.

Caffeine intake in long-distance events

12:18 -

  • Studies on military personnel show improvements in fatigue resistance with caffeine intake for ultra events lasting multiple days.
  • However, no studies are looking at ultra-endurance sports.
  • For Olympic distance or marathons (2-3 hour races), if you have a decent caffeine intake an hour before the start and another caffeine intake before the event's start, you would have enough caffeine in your system to have a decent effect throughout the race.
  • It would taper by the end of the race, but it would not be significant. 
  • Many elite marathoners will take a caffeine drink in the second third of the race because they could get a boost in the last 2-3 miles.
  • A mistake would be to save the caffeine gel for the final miles of the race, but we are so close to the race that it will only give you a boost psychologically. 
  • However, it will only help later.
  • Therefore, taking caffeine one hour, immediately before and mid-race, is a good strategy for these events.
  • When thinking of middle distance triathlons (4-6h), I see athletes follow a pre-caffeinating routine, but they top it off with another 2-3 doses during the race. 
  • For Ironman and ultras, some athletes perform better with pre-caffeinating routines. Still, there is potential for some people to moderate caffeine before the start because you will feel the effects during the race to mitigate the fatigue that will happen later.
  • For Ultras, timing comes into play, and I had seen examples where people abstained from caffeine before the race and used it strategically to get through the nighttime when body cycles tell them to sleep.
  • You can use the caffeine effects to decrease fatigue perception and increase awareness by taking them later in the race.
  • In an Ironman, taking caffeine before the start could still be wise because swimming in the front group can be a crucial part of the race.
  • On the other hand, if you have anxious people before the start, the addition of caffeine could augment the effects.
  • For example, I had a vital race late in the afternoon, and by taking a considerable amount of caffeine combined with the nerves, my heart rate at the start of the race was 160 bpm, and I was feeling anxious and overstimulated.
  • It settled as the race progressed, but it was not a pleasant experience.

Scenarios where people might want to avoid taking caffeine

20:25 -

  • We have some people with different levels of sensitivity to caffeine and people who metabolise caffeine at different speeds.
  • If caffeine has an anxiety-inducing effect, you might be someone for whom caffeine might be detrimental to performance.
  • 20-30 % of people do not find caffeine advantageous.
  • Our dataset of 120 athletes showed a higher percentage of athletes using caffeine across various sports. Some took small doses, while others took large doses.
  • In our latest blog, we have created a diagram of three overlapping circles with three questions: Did you previously use caffeine in a race? Did you have anxiety symptoms associated with taking caffeine in your daily routine? If yes, you should not use it. Do you take coffee and tea regularly? 
  • If the answers are all positive, caffeine ingestion will likely benefit performance. Two out of three, you can test and play around with it.
  • If you have one or none, caffeine might not suit you.
  • For example, my wife cannot drink coffee. She gets all the adverse effects.

Using caffeine in races

24:39 -

  • Like any part of your equipment, nutrition, or strategy, it is essential to understand how to use it in a race. 
  • You must know the timing and dosage of products and try them in some crucial, more demanding sessions.
  • It is helpful to use it in low-key races because even though they do not simulate the effects of your "A" race, you cannot simulate the nerves of racing in training. The "C" races naturally bring race anxiety, and you can check how you respond to that.

Potential downsides of caffeine ingestion

25:46 -

  • There are reports of GI distress in people that consume large amounts of caffeine. 
  • It is the case of starting with a lower dosage and working until you reach a point where you are at the higher end of the dosage or feel you do not benefit from it. The more you take, the bigger the risk of GI distress.
  • However, it is challenging to understand the roots of GI distress during races because the intensity is higher, blood flow around your stomach is lower, and GI issues are prevalent.
  • Regularly, you cannot point out one single factor. You will have to do trend analysis to see whether you have encountered similar circumstances with and without caffeine.

General recommendations for caffeine intake before and during the event

27:43 -

  • Up to faster Ironman athletes, intaking caffeine before the race is a good idea. If you have breakfast many hours before the start, taking some caffeine 2-3 hours before the start will not harm you, especially if it is part of your general "wake-up" process.
  • For example, for a 70 kg athlete, I recommend taking 200-300 mg one hour before the race, followed by a top-up dose in the last 10 minutes if you can.
  • In this way, you have the peak before the start of the race, and that level remains for one hour or more until you start taking caffeine during the race.
  • The top-off dose comes down to availability and preference. It is an excellent method to get both carbs and caffeine if you have a lot of caffeine gels.
  • Some gels have small doses of caffeine. (20-45 mg) Therefore, you can take some of those more frequently throughout a bike race or middle distance.
  • I do not think there is a right or wrong decision considering caffeine ingestion. You want to be mindful of the total amount you are taking in.
  • We have examples of athletes that were unaware of some products they were taking that had caffeine.
  • They would find themselves overconsuming caffeine, so like the other points (carbs/hydration), it is crucial to have a broad idea of the absolute values you are taking and the products you have at your disposal.
  • For example, we analysed Leo Chevalier in Ironman Mallorca in 2021, where he had the misfortunate of his bottle bouncing off his bike, which had most of his gels for the bike ride. Therefore, he was taking gels from the course and took many caffeine gels to hit his carbohydrate numbers.
  • He consumed around 1000 mg of caffeine (12-14 mg/kg).
  • He won that race and did not report any adverse GI problems during or after the event. However, he did not want to take so much (maybe half of that).
  • Of course, if you race later in the day, consuming caffeine might disrupt your sleep, which can be detrimental to recovery.
  • Once you have established if caffeine works for you, study the dosage that works.
  • All the studies give us an overview of what a good strategy might look like in a race. (3-6 mg/kg)
  • However, we must be mindful that the early doses of caffeine will eventually disappear from the body. Leo took 14 mg/kg of caffeine, but most of it was not in his body by the end.
  • We do not want to go above those higher recommendations because reduced benefits from higher intakes and higher risks of GI issues seem to exist.
  • Moreover, in our database, athletes performed well in various caffeine intakes. Therefore, like most things in triathlon, you need to do the test on yourself.

Caffeine intake case studies

37:20 -

  • Most individual case studies are on our website.
  • We have 15 case studies where athletes consumed caffeine during middle-distance triathlons, and the average time was 4h08min. (men and women)
  • The average caffeine consumption is 3.5-3.6 mg/kg, which includes the pre-intake of caffeine for many athletes.
  • For Ironman events, we have nine case studies with an average time of 9h45min, and the average was 6.5 mg/kg of caffeine. (the longer you go, the more caffeine you can take and tolerate)
  • If you race for nine hours, your body will have metabolised the caffeine you take before the race by the end.
  • It is not the same as taking 6.5 mg/kg in a single dose.
  • The dosage of caffeine is like drinking alcohol. You will get drunk quickly if you attend a party and drink ten shots in one go.
  • Whereas, if you drink spread out over a few hours, the alcohol amount in your blood will increase over time, and you might only need to get some small drinks throughout to have a pleasant evening.
  • You have to understand the rate at which we consume caffeine.
  • Of course, there is a range of values that athletes consume caffeine. One athlete can consume 8 mg/kg, the other 11 mg/kg (the athlete reported having problems sleeping after).
  • You might point out caffeine intake, but many athletes struggle to sleep the night after an Ironman.
  • However, we also had an athlete who consumed less than 1 mg/kg during the race (that won the race).
  • While everyone needs energy and hydration intake right, caffeine is individual to performance. 
  • We are talking about something that can give a slight edge from not taking it.
  • I see caffeine being a game-changer in very long ultra-distance stuff, where you must go through the night.
  • If you are doing 12 hours or more, the prevalence of people DNF is because of fatigue and unwillingness to continue at 3-4 am when your body clock wants to rest.
  • Using caffeine during the night will give you a bump, and the sunrise will wake you up eventually.

Ultra-endurance event case study

46:32 -

  • Damien Hall is a world-class ultra-runner that did the Spine Race (multi-day, non-stop ultra race in the winter).
  • He was leading this race and probably would win it but had to pull out because he slipped and strained his groin after 52 hours.
  • At that period, he took 1400 mg of caffeine, 22 mg/kg. Of course, any caffeine taken at the start would have metabolised out of his system.
  • If you break down the 52 hours, it would be five Ironman races, meaning he was taking 5 mg/kg of caffeine on that time distance.
  • So it was not an unreasonable dosage for him and was working. He was dripping caffeine throughout the race, and it was not giving him any detrimental effect.

Ideal caffeine intake for Ironman age-groupers

48:40 -

  • It is plausible that age groupers can take more caffeine because they race for more time. However, it will depend on your daily usage and your tolerance level.
  • If you are a heavy daily user of caffeine, you will need more to have the same stimulus level.

Best sources of caffeine

49:56 -

  • It is about finding dosage forms that work for you. Sports products' primary advantages are that the dosage is precise. If you take 100 mg of caffeine gel, you will get something close to that value. If you have an expresso, there are so many variables in the production that the variability of caffeine you get is high.
  • However, if it is a more pleasant way to start the day, it is something viable to consider.
  • The other advantage of sports products is that you carry them during the races and know the dosage you regularly get.
  • Of course, estimating dosages on the move is challenging, but if you have raw numbers on your head, it can help your management of the race. coca-cola has ten g/carb per 100mL and 30 mg of caffeine)

Additional considerations on caffeine

52:59 -

  • The process of using caffeine is figuring out if it works for you. It works for most people, but it might not work for you.
  • Most people answer that quickly in their lives because people expose themselves so much to caffeinated products that they figure out if they work or not.
  • Moreover, we figure out our degree of sensibility and tolerance.
  • For example, here in Precision Hydration, you do not see me around the coffee machine after 11 am, and it is rare if I have more than 2-3 coffees a day. In contrast, I have colleagues that smash 5-6 strong coffees a day with no problems at all.
  • As an athlete, the next step is to get the number right. We have many resources on our blog to get you in the zone.
  • Science says it may be 3-6 mg/kg, but you might be better with seven or two.

Sodium replacement during a race

55:50 -

  • Even with our data and case studies, it is still a challenging question to answer.
  • If you have an athlete with a low sweat rate and a low sweat sodium concentration, we see that athletes can go through a half-Ironman with little or no sodium intake and perform well. They need to drink fluids, but replacing it might be unnecessary if they lose so little sodium.
  • These athletes seem to perform better in hotter conditions because they are economical with their sweat. They do not need to replenish sodium and can drink only by feel.
  • Conversely, we have athletes with high sweat and sodium losses. 
  • The battle then is not finding the percentage they can replace but figuring out how much they can tolerate.
  • If they sweat 2.5 L per hour and lose close to 2000 mg/L of sodium, their gut cannot tolerate that.
  • We have seen athletes drinking more than 1 L per hour with 2000 mg/L of sodium, which enabled them to finish and be competitive in longer, hotter races. However, they might only replace 50 % of their losses.
  • If you drink a sports product, you get some sodium along with some electrolytes. For some people, that is enough, while others have to try to consume as much sodium as possible.
  • It is sensible if you can replace 70-80 % of the losses, but that is still an estimation. 
  • We want to achieve homeostasis when you try to drink and consume fluid and carbohydrates to keep functioning.
  • We know that aiming to cover 100 % of the losses might not be helpful because it puts much strain on your stomach and GI tract.
  • We can finish slightly dehydrated and still recover well from the race.
  • Replacing a high percentage of the losses helps with homeostasis, and as long as it is not causing GI distress, you can drink slightly less than you lose.
  • This topic is highly individual, as we are getting closer to understanding how much each athlete needs to replace to stay in homeostasis, but it will depend on the circumstances.
  • We believe an absolute fluid and sodium loss causes a catastrophic change in homeostasis that leads to problems like cramping.
  • However, this will depend on the athlete's size and the intra- and extracellular fluid each athlete has.
  • It will also depend on your hydration status. Athletes tend to overdrink before an event, which can harm the sodium levels because you pee so much that you can start the race with low sodium stores.
  • For most people, there should be a total sodium deficit that causes them to break down.
  • There has been some debate around this topic of hydration. Some people do not agree with our work at Precision Hydration, but they come from a place where they had previous problems with electrolyte drinks.
  • So, they extrapolate that it does not matter to anyone. However, our database shows that there are athletes for whom this is crucial even to finish the event.
  • If you check for extreme case studies, check Luke Henderson, a top age grouper with exceptionally high sodium and sweat loss.
  • Some coaches advised him that he would only need to drink water or drink to thirst, and he ended up in the medical tent several times because of it.
  • We implemented an aggressive strategy, and he started finishing races and getting PBs.
  • However, we do not want to push that you need large volumes of fluid and sodium to succeed. It is all about individualisation.
  • While you might sit between the extremes concerning hydration, some nuances allow checking where you can sit in the range.
  • Once you figure out how much sodium and fluid you need, we can help you create a strategy to succeed.

Future projects, products to be released by Precision Fueling and Hydration

01:06:43 -

  • The caffeine gel we launched has 30 g of carbs and 100 mg of caffeine.
  • We wanted to ensure the label was clear for the athlete to hit their targets easily.
  • We also wanted the product to taste good. So far, athletes in different environments have tested them, so it was the product people asked about the most, and we are excited that we can get it to market.
  • We launched a fueling and hydration plan. We had the online version of the sweat test, where people place their sweat fluid and sodium losses.
  • We also developed a calculator that allows athletes to estimate how much carbs they need for a specific intensity and duration.
  • It covers triathlon, cycling and running at the moment, and we want to add other sports as the development continues. And we are proud of that product because of the work put into that product.
  • We collaborated with different teams from various levels and accumulated a lot of knowledge about fueling and hydration.
  • We tried to put it all in the fueling planner with all that knowledge.
  • You can put all the data concerning the race and your estimated sweat losses and historical performance.
  • The result is a fueling and hydration plan that presents guides and allows you to play around with the ranges that are right for you.
  • Hopefully, that will cover a huge market gap and avoid people having to do much research themselves or hiring a sports dietitian to do that for them.
  • We wanted to give people access to information that allows them to decide for themselves. Then if they want to get more services from us, they can get them, and we start from an advanced point because they have a basic understanding of their nutrition plans.

Rapid-fire questions

1:12:19 -

What is your favourite book, blog or resource?

Caffeine: How Caffeine Created the Modern World by Michael Pollan

What is an important habit that benefited athletically, professionally or personally?

Waking up and doing my exercise session in the morning. It allowed me consistency in competing with younger athletes.

Who is someone you have looked up to or who has inspired you?

Paul Van Doren: wrote a fantastic book called Authentic: A Memoir by the Founder of Vans about a person that achieved a lot in his life. I found this book inspirational, and I recommend it to everyone.


Bernardo Gonçalves

Bernardo is a Portuguese elite cyclist and co-founder of SpeedEdge Performance, a company focused on optimising cycling and triathlon performance. He writes the shownotes for That Triathlon Show, and also produces social media content for each new episode.

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