Is Triathlon an Aerobic or Anaerobic Sport? Why You Need To Practice Both!

Triathlon is one of the most demanding ultra-endurance sports in the world and that’s why so many of us are drawn to its challenges. But it’s about more than transition times and wetsuit hacks. Understanding the science behind the sport can help you maximize your training and make you a better athlete overall. Plus it’s just fun to learn about.

Let’s get the foundation down first: Is triathlon an aerobic or anaerobic sport?

Triathlon is a sport that relies heavily on the cardiovascular system (hence why refer to these kinds of activities are often referred to as “cardio”). Any endurance sport that can be done for a sustained period of time while utilizing oxygen as the primary source of energy production is considered an aerobic sport, thus, Triathlon is categorized as an aerobic sport.

We’ll go into what that means and how you can use that information to train more effectively.

Why Is Triathlon Aerobic?

As explained earlier, Triathlon is considered an aerobic sport because it is a sport that relies heavily on the cardiovascular system.

Generally speaking, there are two broad types of physical activity: aerobic and anaerobic. Aerobic means “with oxygen” while anaerobic means – you guessed it – “without oxygen.”

We’re going to look at these two types of activities (aerobic and anaerobic) more closely before diving into what that means for triathlon. We’ll also look at the ways you can train both of these systems for maximum results.

Aerobic Training

Aerobic activities require using oxygen to produce energy (as mentioned above, the word aerobic translates to “with oxygen”). Breathing controls the amount of oxygen that makes it to the muscles, which is then converted to energy to help the muscles move and burn fuel (Source). This is very common in endurance sports, as you’ll see below.

Notice that the first three activities turn into a triathlon!

Examples of aerobic exercise:

  • Swimming
  • Cycling
  • Running
  • Dance

Anaerobic Training

Anaerobic translates to “without oxygen” which is the key difference between this type of training and aerobic training. Rather than using oxygen as the main energy source, anaerobic activity uses the glucose that is already stored in our muscles. It is a much quicker and more immediate form of energy, which is why you’ll experience it during high-intensity efforts or even strength training and stretching (Source).

Examples of anaerobic exercise:

  • Bench press
  • Stressing
  • High intensity interval training
  • Short sprints (on the bike or running)

It’s important to incorporate both aerobic and anaerobic exercise in your training to get the full benefits of each. You can do this on your own by dedicating certain days to each type of workout, or by following a pre-made training plan.

For more on this topic, check out our post Do Triathletes Lift Weights? Is The Gym & Crossfit For Triathletes!


Also, check out our post titled ” Swim or Gym – Which Is Better? Should You Swim Before or After a Workout!

How to Improve Triathlon Aerobic Capacity (workouts)

Increasing aerobic capacity means increasing the amount of oxygen your body can take in and convert into energy. This is often referred to as VO2 max, which you might see referenced in your training plans or if you track your workouts using a smartwatch.

Most training plans will include efforts that push your VO2 max threshold, usually in the form of intervals or pushing your pace a bit faster than your race pace for a period of time within the workout. Runner’s World gives the example of pushing anywhere from 10 to 30 seconds faster than your 5K race pace. You should hold that pace for either a certain amount of time (like 3 to 5 minutes) or for a distance (800km). This would be followed by an easy jog for 3 to 4 minutes. Continue to repeat this cycle 3 or 4 times (Source).

Following a specific training plan based on your skill level, triathlon distance, and the time you can devote to training is your best bet, especially if you want to see real improvement. Training Peaks is one platform you can use to find a training plan based on your needs. You can also try and find free options online, though they may not incorporate threshold training for improving your VO2 max.

Another thing to keep in mind is that measuring VO2 max requires the use of some very specific equipment. Your watch may have a feature that claims to measure VO2 max, but it is mostly a guess based on the data that’s inputted. If you’re really serious about learning your VO2 max, you can reach out to local colleges and universities and see if they have the equipment to test you.

What Is the Anaerobic System?

The anaerobic system is the way for the body to quickly and efficiently turn glucose into usable energy during exercise, a process that produces ATP (adenosine triphosphate, A.K.A. energy-carrying molecules). This process can power muscles for anywhere from 10 to 30 seconds for intense efforts. It actually bypasses the use of the aerobic system, though that will kick back in once the anaerobic effort has been tapped out (Source).

Anaerobic capacity is measured differently than the aerobic system (which is typically measured through VO2 max). You would measure your anaerobic capacity by seeing how much power you can put out during a 30-second sprint test. You can also measure how many times you can repeat this level of effort, often referred to as repeatability.

While triathlon is primarily an aerobic sport due to the lengthy endurance efforts, you’ll still want to train your anaerobic system. This will help when push comes to shove and you need to power up a hill or sprint across the finish line.

What Are the Benefits of Aerobic and Anaerobic?

You’ll want to incorporate both aerobic and anaerobic exercise into your training. There are benefits to each that will help you become an all-around more powerful and effective athlete (Source).

Benefits of Aerobic Exercise

The benefits of aerobic exercise will primarily be within your cardiovascular system (which is why aerobic exercise is often called “cardio”).

Here are just some of the benefits:

  • Reduced risk of heart attack
  • Reduced risk of stroke
  • Increase stamina
  • Decrease fatigue during exercise
  • Boosts mood
  • Can help lower or control high blood pressure

Of course, you’ll also find benefits within the sport by increasing the amount of time you can maintain your endurance efforts.

Benefits of Anaerobic Exercise

Anaerobic exercise may not seem as important as aerobic exercise is for a triathlete, but it still needs to be incorporated into your training. This will help you become a better athlete all around and can be a way to prevent injuries.

Here are some benefits of anaerobic exercise:

  • Strengthens bones
  • Increases muscle strength (and sometimes size)
  • Increases stamina
  • Increases power output (like your wattage on the bike)

Having a higher anaerobic capacity will also help you during those times when you really need to push during a race (looking at you, hilly courses).

Things to keep in mind

It’s always important to follow a structured training plan created by a professional.

This will help ensure that you’re targeting both aerobic and anaerobic efforts throughout the duration of your training.

Not only will this make you a better triathlete, but it will also make you healthier in the long run. It can be easy to neglect the anaerobic system, especially after you’ve already spent hours on the bike or doing brick workouts.

But having a designated time to work on sprints, strength, and mobility will help you stay strong and (hopefully) injury-free.

Aprill Emig

Based out of Duluth, MN Aprill loves to write about the outdoors, education, and all forms of adventure. You can find her mountain biking, running, or playing roller derby.

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