Coffee before a triathlon: good or bad? (definitive answer)

It’s not because I do not enjoy the taste of coffee that I haven’t noticed all my friends and fellow triathletes being avid coffee drinkers. Like them, you most likely enjoy your morning coffee and it may even be part of your daily routine. It gives a little boost to start the day with a bit of energy, and its warmth is very appreciated.

But you probably heard about some of the negative effects of coffee: like nervousness, dehydration, dizziness, and chronic fatigue… which generally appear with high consumption of coffee. It might have made you wonder if coffee can affect your performance in triathlon.

Should you just stop drinking coffee, or just avoid your morning coffee on race day? and does it really affect your performance? Let’s see in detail the rights and wrongs about coffee for triathletes.

Grab your nicest mug and enjoy the read!

Is drinking coffee good for a triathlete performance?

Coffee may increase performance in many sports if taken in moderate amounts. But coffee is particularly good for endurance sports such as running, swimming, and cycling as studies proved on several occasions. As such, coffee is a great drink to enhance triathletes’ performance.

Coffee increases endurance by delaying muscle fatigue and increasing the availability of glucose. It also improves motivation and alertness while reducing the perception of pain. These are useful benefits during a race. Coffee even helps muscle recovery after exercising!

Recent studies as shown that coffee does not cause dehydration during sports contrary to the common belief. Indeed, a meta-analysis performed in 20141 on 16 scientific studies shows the diuretic effect of caffeine does not exist while exercising. The diuretic effect of coffee does exist at rest but not when doing sports. That’s the reason why this common belief exists.

Of course, that holds true as long as you don’t drink large amounts of coffee. It makes sense that if you drink a lot you would need to pee at some point. But if taken into the recommended amount suggested by Joy G. Shena et al.2, 2 to 3 short cups (8 oz) of coffee for someone that weighs 150 pounds should increase performance without causing dehydration.

1 Caffeine and diuresis during rest and exercise: A meta-analysis. Yang Zhanga et al.

2. Establishing a relationship between the effect of caffeine and duration of endurance athletic time trial events: A systematic review and meta-analysis. Joy G. Shena et al.

Is drinking coffee before a triathlon a bad idea?

It is ok to drink coffee before a race. In fact, taking coffee before a triathlon or an Ironman can increase your performance between 1 and 6%2. The longer the event, the better the benefits. The effects also vary among people due to genetic predispositions, but they are never negative.

These benefits, which average around a 3% increase in performance, have been backed up by 40 studies2 that range from 1997 to 2015. So there is no doubt coffee has positive advantages for endurance sports such as triathlon.

Note it is also common to see athletes consume caffeine in the form of snacks during long-distance events, such as ultra-distance triathlons or long-distance cycling. Thus, the consumption of caffeine during an event seems also beneficial, but it hasn’t been as intensely backed up by scientific research.

2. Establishing a relationship between the effect of caffeine and duration of endurance athletic time trial events: A systematic review and meta-analysis. Joy G. Shena et al.

When is the best time to drink coffee before a triathlon?

The best recommended time for drinking coffee before a triathlon is 30 minutes before the start. Indeed coffee takes approximately 1 hour to reach its maximum concentration in your body and then fades slowly. Drinking coffee 30 minutes before a race will therefore optimize the coffee concentration throughout the exercise.3

On this graph, you can see that caffeine concentration is at maximum after 1h. But its concentration is already high after 30 minutes and stays so for 6 hours. Thus taking it 30 minutes before the race will give you the benefits of caffeine right from the start of the race. Then, 30 minutes into the race, you will feel the maximum of these benefits, at a moment when muscle fatigue may start to kick in.

Please note that if you can’t take your coffee 30 minutes before the race due to preparation, drinking it 60 or 90 minutes before is also very fine. Indeed caffeine fades very slowly, so you will still have great benefits if you take it earlier than the optimum 30 minutes before race start.

Taking caffeine in other forms than the usual hot beverage may also change the timing. Some studies suggest that caffeine capsule reach their maximum concentration in the body in only 30 minutes. Fortunately, in any of its forms, caffeine takes a long time to decay in the body.

So other forms of caffeine such as capsules, gels, and snacks are also great if you cannot drink a coffee just before the race. All you need to do is respect the right dosage of caffeine which I cover in the next paragraph.

3 Pharmacokinetic analysis and comparison of caffeine administered rapidly or slowly in coffee chilled or hot versus chilled energy drink in healthy young adults. John R. White Jr et al.

How much coffee should I take before a race? (in cups)

To increase the benefits of coffee before a race, drink between 1.36 to 2.72 mg of caffeine per pound of body weight. That represents 3 to 4 coffee cups (brewed) for someone weighing 150 to 160 pounds, or 1 Grande Americano from Starbucks.

Here is how much coffee you should drink before a race depending on your weight:

Body weight
Body weight
Instant coffee cup
(8 oz) or Espresso
Brewed coffee cup
(8 oz)
Grande Starbucks
Americano (16 oz)
100 lbs45 kg3 to 42 to 31
110 lbs50 kg3 to 42 to 31
120 lbs54 kg3 to 52 to 31
130 lbs59 kg3 to 52 to 31
140 lbs64 kg4 to 52 to 41
150 lbs68 kg4 to 63 to 41
160 lbs73 kg4 to 63 to 41
170 lbs77 kg4 to 73 to 51
180 lbs82 kg4 to 73 to 51
190 lbs86 kg5 to 83 to 51
200 lbs91 kg5 to 83 to 51
210 lbs95 kg5 to 84 to 62
220 lbs100 kg6 to 94 to 62
230 lbs104 kg6 to 94 to 62
240 lbs109 kg6 to 104 to 62
250 lbs113 kg6 to 104 to 72
260 lbs118 kg7 to 114 to 72
270 lbs122 kg7 to 115 to 72
280 lbs127 kg7 to 125 to 82
290 lbs132 kg7 to 125 to 83
300 lbs136 kg8 to 125 to 83

If you follow the recommended amount from this table, you should have a 3% performance increase and avoid any dehydration risk.

Should you cut caffeine before a race?

It’s not necessary to cut caffeine before a race. On the contrary, coffee enhances performance by around 3% when consumed before the race. Just make sure not to exceed 2.72 mg per pound of body weight to avoid negative effects. That represents 435 mg for someone of 160 pounds or 4.5 cups of brewed coffee.*

* or 6 mg per kg, representing 420 mg for someone of 70 kg or 4.5 cups of brewed coffee.

If you are a heavy drinker though, reducing your intake before the race is probably a good idea. Indeed, coffee addiction is known to cause chronic fatigue and lower your immune system. So if you are a coffee addict, cutting in half your consumption the days prior to the race is probably better. And if you feel like it, try to cut it down entirely.

Then, when you will take the recommended amount of caffeine during race day (see table), you will feel empowered and have much more benefits. The coffee will act as a boost and not be filling your usual craving state.

Does caffeine in other forms than coffee also work?

Yes, caffeine in the form of capsules, chewing gum, energy gels, energy drinks, and caffeinated snacks, will have the same positive effects as the regular beverage. What is essential is to follow the recommended 1.36 to 2.72 mg of caffeine per pound of body weight.

The form in which you take the caffeine may change slightly the time the effects start to kick in, but we are talking about a difference of 1-hour maximum. After that, there are no major changes since the caffeine takes a long time to get out of your system.

However, be cautious when you ingest caffeine in other forms. First caffeine quantity varies a lot depending on the products. For instance, gels may have caffeine spanning from 30 mg to 160 mg. But gels also come with other nutrients: carbs and electrolytes. Taking too many carbs in order to have the right amount of caffeine is probably not ideal. So make sure to read what is written on these products before!

In my opinion, caffeinated gels are better to be taken during the race. They will give you energy, help with hydration, and reboost your caffeine levels.

Pre-race, I believe the caffeine capsules are the best. Many have exactly 100 mg of caffeine, similar to brewed coffee. They have the benefits of coffee without having to pee afterward. Furthermore, they are handy to carry in a pocket. It’s simpler to ingest before a race where having hot coffee nearby is not always possible.

If you want to go with the capsules, you can buy these ones on Amazon. Then take the brewed coffee column in my previous table to know how many capsules to take.

What about the maximum caffeine limit in official races?

Caffeine is only restricted by the National Collegiate Athletic Association (NCAA). Its concentration in urine should not exceed 15 µg/mL, a concentration that you cannot exceed if you follow the recommendation of 1.36 to 2.72 mg of caffeine per pound of body weight.

Thus there is no need to worry. Reaching the limit of 15 µg/mL is quite impossible for any normal coffee drinker. And this rule only applies to triathlons organized by the NCAA, which means you still need to be in college!

In all scientific studies performed, the lowest coffee ingestion someone has done to reach this limit was 4.082 mg per pound of body weight4. For someone around 160 pounds, that means drinking 7 brewed coffee cups (8 oz) or 3 Grande Americano from Starbucks (16 oz).

Thus, if you stick to my table on how much coffee you should drink before a race, you should not worry about this limit. 🙂

4 Prevalence of caffeine use in elite athletes following its removal from the World Anti-Doping Agency list of banned substances. Juan Del Coso et al.

Talking about rules, did you know you could take a break during a triathlon race? There are rules to follow not to get disqualified, but it is possible. Please read my article “How to take a break during a triathlon”, if you want to know more.

Things you need with your smart tra...
Things you need with your smart trainer

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Posts

Black Friday Amazon deals

These are affiliate links to They are designed to provide us a mean to earn advertising fees.