Cardio Capacity_ What to Know

If you’re looking for an accurate way to understand how your body is working during exercise, you may want to consider testing your aerobic capacity. It is one way to track your fitness level, and can be used in addition to various fitness and endurance tests.

This article will discuss aerobic capacity, how it is calculated, how to build it, and how it compares to aerobic endurance.

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Your aerobic capacity refers to the maximum amount of oxygen your body can use at one time during an intense exercise.

When you perform any type of aerobic exercise, your body is using oxygen to fuel metabolism (chemical reactions in cells that change food into energy) to give your body energy for movement.

For more intense exercise or quick movement, your body switches to another type of metabolism that doesn’t use oxygen. However, your body can only sustain this type of metabolism for a very short time, like 10 to 15 seconds.

A higher aerobic capacity allows you to perform more intense movements while continuing to use oxygen.

How to Calculate Aerobic Ability

Your aerobic capacity is measured by assessing your VO2 max, which is the maximum volume of oxygen you can use at one time.

Some wearable fitness devices—like Fitbit, Apple Watch, and Samsung watch—provide an estimate of your VO2 max based on your heart rate during exercise, age, weight, and sex.

However, these devices can only provide a rough estimate and can’t give you a precise measurement. But if you don’t care to know the exact number, you could just use this option.

To get an accurate assessment of your aerobic capacity, you’ll need to get an indirect calorimetry test performed. This test could be difficult to find depending on where you live. Check for sports labs, universities, or hospitals in your area that may offer the test.

An indirect calorimetry test involves fitting a mask to your face to measure your breathing while performing an increasingly intense workout on a treadmill or bike. It typically takes five to 10 minutes to complete the breathing test.

Aerobic Capacity vs. Aerobic Endurance

While aerobic capacity and aerobic endurance are similar, they aren’t the same thing, in that:

Aerobic capacity is the maximum amount of oxygen your body can use at one time.

Aerobic endurance measures your ability to do moderate- to high-intensity exercise for an extended period of time.

The two can influence each other and be related, but they don’t always correlate. For example, you could have a high aerobic capacity and endurance for swimming, but have trouble with endurance running.

Aerobic endurance is influenced by the strength and capacity of the specific muscles being used in that exercise.

How to Build Aerobic Capacity

Now that you understand your aerobic capacity, you can focus on ways to increase it. Here are some of the ways to build your aerobic capacity.

Interval Training

Interval training is one of the most effective ways to increase aerobic capacity. A 2017 study found high-intensity interval training (HIIT) improves aerobic capacity more than maintaining a consistent moderately intense pace.

If you want to build aerobic capacity, adding interval workouts into your exercise routine will help. Examples of interval training include Tabata, cardio HIIT, and HIIT with weights.


Cross-training, meaning using multiple types of exercise, helps build aerobic capacity and endurance. For example, to cross-train you could mix in days of running, sprints/walking intervals, strength training, yoga, and low-intensity days.


Aerobic capacity refers to your body’s ability to efficiently use oxygen. The greater your aerobic capacity, the more intense exercise you can do while continuing to use oxygen to produce energy. Aerobic endurance, on the other hand, refers to how long you can perform moderately to highly intense exercise.

You can build your aerobic capacity with interval training and mixing up your training methods.

A Word From Verywell

Your aerobic capacity is just one of the measurements of your aerobic and cardio fitness levels. Learning your aerobic capacity can be an interesting method to track your progress throughout your health and fitness journey.

If you have any questions about your health and fitness degree, talk with your healthcare provider as well as other health and fitness specialists.