How Many Calories Are Consumed In Triathlons; Why Is It Important? All Distances

A triathlon is a multisport event that comprises three different sports. These sports include swimming, biking, and running. Triathlon is not a simple event as you would find yourself working out every muscle in your body, causing you to run out of energy before you even know it.

Triathlon is a lot of work, and you might be wondering how many calories you burn during the race.

So how many calories does a triathlete consume in a giving triathlon race? For a triathlete with an average body mass of 70kg, the triathlete consumes 1,600 calories in a sprint triathlon, 2,250 calories in an Olympic triathlon, and around 10,000 calories in an Ironman triathlon.

The table below provides an approximate snapshot of the number of calories burnt during the triathlon event for the three major distances.

SPRINT227682675I hr. 45 min1584
OLYMPIC4149768403 hrs.2230
IRONMAN8404582420012 hrs. 40 min9622
Number of calories burnt by a triathlete with an average body mass of 70kg during a triathlon.

Let’s delve deeper to better understand the different triathlon distances and how we arrived at the approximate total calories burnt for each but first make sure to check out our post on Triathlon Nutrition Guide: Before, During & After Race (What Not To Eat !!!)

Also check out our post on Are Ready-made Energy gels better than their natural substitutes? Honey, Maple-Syrup, Datesโ€ฆ

How Many Calories Are Consumed In Sprint Triathlon

The sprint triathlon includes a 750m swim, 20km bike ride, and 5km run. A sprint triathlon is the second shortest triathlon distance with the super sprint triathlon being the first. Despite its short distance, you would still burn some calories.

So you still have to properly fuel your body for the race, and your body still needs proper nutrition no matter the distance, activity, or amount of running youโ€™ll be doing.

A good understanding of the number of calories burnt during a sprint triathlon will help you know what your body needs during the event.

For triathletes, several factors play a role in how many calories are burned during a race. But the major three factors are bodyweight, distance covered, and speed during the event.

A person weighing 70kg swimming a distance of 750m would burn approximately 682 calories each hour. The swim typically takes up to 20 minutes, so the total calories burned would be around 85 to 227 calories.

A 20Km bike ride would take approximately 38 minutes.  For a person that weighs 70 kg, the calories burned covering this distance would be around 682 calories.

It takes 45 minutes for an average triathlete to complete a 5 km run. When you run at this particular pace, you burn up to 15 calories per minute per kg body mass. This equates to approximately 675 calories for a person weighing 70kg.

The number of calories burned can vary according to your weight, speed, and your training beforehand.

So, the total average calories consumed during the sprint is approximately 1,584 calories.

That amount could increase for triathletes that run faster and decrease for the athlete who has less body mass. (source)

How Many Calories Are Consumed In Olympic triathlon.

An Olympic triathlon requires an athlete to swim1.5 kilometers, bike 40 kilometers, and run 10 kilometers. The average person takes slightly more than three hours to complete an Olympic-distance race, and this time is reduced to 1 hour and 47 minutes for pro-athletes.

Although the point to notice is that even if someone finishes it in half the time, they are burning the same amount of calories because they are putting in more effort, and the calorie requirement increases with speed and effort.

To get an estimate of the average calorie requirement, we would use the approximate values of:

  • 0.13-0.16 calories per minute per kg for swimming,
  • 0.15-0.17 calories per minute per kg for biking, and
  • 0.10-0.20 calories per minute per kg for running.

Although this is not highly precise because of all the variables influencing your calorie requirement, this is good enough to give you a basic idea of your calorie requirement and calorie usage. (source)

The calorie requirement equates to the calorie expenditure so we can say that;

The number of calories burnt during the Olympic swim for a 70kg triathlete is approximately 0.16 calories x 37 minutes x 70 kg = 414 calories

The Olympic triathlon swim is usually done in open water and takes an average of 37 minutes to complete. Depending on your speed and ability to swim effortlessly in the water, it could take anywhere from 23 to 48 minutes total.

The number of calories burnt during the Olympic bike ride for a 70kg triathlete is approximately 0.17 calories x 82 minutes x 70 kg = 976 calories

A 40 km ride takes, on average, 1 hour and 22 minutes (82 minutes) to complete during an Olympic triathlon.

Note that, as the time increases for the lower age group and triathletes, calorie requirement also increases.

The number of calories burnt during the Olympic run for a 70kg triathlete is approximately 0.20 calories x 60 minutes x 70 kg = 840 calories

For a 10 km run, it takes the average triathlete about 1 hour to complete.

So calories consumed from completing in Olympic triathlon is approximately 2,230 for an average person of 70kg.

We recommend that you also check out our post titled “Does Running Outside Burn More Calories Than On a Treadmill ?!

Th Many Calories Are Are Consumed In Ironman triathlon.

Ironman is a long event that takes about 12 hours and 35 minutes for the average triathlete.

Triathletes complete a Swim distance of 4 kilometers in 1 hour and 15 minutes, a Bike distance of 180 kilometers in 6 hours and 25 minutes, and a Run distance of 42 kilometers in approximately 5 hours.

Recall that the calorie requirement equates to the calorie expenditure, so according to the calorie requirement we mentioned above, we need approximately 0.13-0.16 calories per minute per kg body mass for a typical average swimming course.

So for a 70kg triathlete, the number of calories burnt for the swim of 1 hour and 15 minutes is approximately 0.16 calories x 75 minutes x 70 kg = 840 calories.

Similarly for biking 180 km, we need approximately 6 hours and 25 minutes (385 minutes). Calories burnt during biking are 0.15- 0.17 per minute per body weight.

So, for a 70kg triathlete, the number of calories burnt for the bike is approximately 0.17 calories x 385 minutes x 70 kg = 4582 calories.

Running approximately takes 5 hours (300 minutes) and calories burnt during this is 0.10-0.20 per minute per kg body mass.

The Run work up to approximately 0.20 calories x 300 minutes x 70 kg = 4200 calories.

We can say approximately, for a person of 70 kg body mass, the average calorie requirement in an ironman triathlon is 9,622. (source)

What Determines The Amount Of Calories Burnt During A Triathlon?

The number of calories you burn during the triathlon race depends on different factors, which include your size, your gender, the race course, your effort at each of the sports, and how long it takes you to complete the race.

There are many variables but let’s look into the effect of distance and effort on the number of calories burned in triathlon.

The effect of distance

First of all, you need to know the distances of the triathlon and the time it takes for you to run each distance. The longer the distance of the triathlon, the more calories you’ll burn.

Olympic triathlons are contested on courses at the International Distance with a 1.5-kilometer swim, a 40 km bicycle ride, and a 10 km run.

Sprint races have the same three legs but they are significantly shorter than the rest of the distances and much easier to race.

Ironman competitions are longer and they have a swim of 4 kilometers, a 180 kilometers bike ride, and a 42 kilometers run, which is the distance of a marathon and burns more calories than any other distance.

Once you know the distances youโ€™ll know how it affects your calorie expenditure/requirement.

 The average person takes slightly more than three hours to complete an Olympic-distance race.  A sprint distance triathlon might take around 1 hour and 30 minutes for the average person or less than one hour for pros.

While Ironman distance triathlons usually finish between 8 and 12 hours for pro- triathletes to an average non-athletic person.

Kids usually take a little longer than that. Find out how much time it takes for kids to race a triathlon.

The effect of a triathlete’s effort

You burn more calories in the hard part of the triathlon where you need to put extra effort. For example, you burn more calories during running and bike because you have to work against resistance than you can burn in swimming.

Check out How much to spend on triathlon energy gel?

Water provides you with the basic force needed during the activity.  Biking requires you to apply force against the resistance of the ground and bike wheel, hence the extra effort and the extra calorie burn.

There are many other variables like age, weight, body mass, BMI, equipment, training, and many others which contribute to your calorie burn. This is why calorie burn for each person is different.

Why Calories Counting Is Important For Triathletes?

As a triathlete, you should get familiar with your calorie requirement because a good understanding of what is required of you to consume before each triathlon event would help you maintain peak performance and good overall health.

Your performance during any triathlon event totally depends on your training and how well-prepared you are for the high level of calorie burn during the race.

If you over-consume food or any other energy drinks you may end up with stomach and intestinal issues and severe cramping.

This will severely affect your health and your performance during the event.

Similarly, if you under-consume, your performance will likely not live up to your expectations and you will find yourself in mid of burnout sooner than you expected.

Under consumption will not only slow down your pace but will also have negative effects even after the triathlon. These include fatigue restlessness and body weakness.

Carefully planning your calorie expenditure and replacement will be key to your performance and your overall health.

Final Thoughts

There are way too many variables covered in this article. This is directed towards giving you a proper idea of the approximate calorie expenditure/requirement.

This can increase according to your external environmental factors, such as your biking route, resistance due to your bike tubing, your speed, age, and your body weight.

Everything contributes to the number of calories burnt during any strenuous exercise. Here is a quick review of the number of calories consumed during a triathlon for the three major triathlon distances.

A person of average body mass 70 kg will burn approximately;

  • 1584 calories for a sprint triathlon
  • 2230 calories for an Olympic triathlon
  • 9622 calories for an Ironman triathlon

For more on the topic of calories and triathlon, check out our post ” Swim, Bike & Run Typical Calories Burned & Timings In Triathlon

Also, check out Is It Okay To Add Alcohol/Vodka to Gatorade/Electrolytes In Triathlon Races?


An extreme triathlete who have competed in dozens of triathlons including IronMans and Extreme triathlons.

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