Aerobic capacity is a great indicator of your overall health and fitness. Not only is aerobic capacity linked to better athletic performance, increased stamina, and a decreased risk of certain diseases, but it’s also positively correlated with other areas of fitness such as muscular endurance, strength, and flexibility. 

Since it’s such a great all-around data point, it’s important to understand what aerobic capacity is, as well as how we can work to improve it. 

In this article, we’ll take a look at exactly that, as well as how you can use VO2 Max testing to work towards improving your aerobic capacity. 

What is aerobic capacity?

Aerobic capacity, also known as VO2 Max, is the point at which the body uses the most oxygen it can, as efficiently as it can. 

Aerobic capacity is closely related to aerobic endurance – the ability to exercise at a moderate intensity for an extended period. This means that aerobic capacity is a great way to estimate our overall cardiorespiratory fitness, and how intensely we can exercise before having to do so anaerobically (without oxygen). 

Aerobic vs. anaerobic exercise 

Aerobic exercise, as the name suggests, is any exercise in which your body effectively processes oxygen to produce energy for your muscles. Steady-state cardio exercises such as walking, jogging, swimming, and cycling are examples of aerobic exercise. 

Anaerobic exercise, on the other hand, occurs without oxygen being used to produce energy. Anaerobic exercise involves a short amount of high-energy activity, such as sprinting, weightlifting, HIIT, jump squats, etc. 

Our anaerobic systems can generate fast bursts of energy – without oxygen – for intense exercise lasting roughly 0-120 seconds. Since we aren’t able to sustain anaerobic exercise for very long, it’s advantageous to be able to maintain exercise aerobically for as long as possible – that is, to have a high aerobic capacity. 

What are the benefits of high aerobic capacity?

A high aerobic capacity is indicative of increased cardiovascular performance. Some benefits of having a high aerobic capacity include:

  • Higher overall fitness level
  • Increased stamina
  • Better regulation of blood sugar
  • Better-controlled blood pressure
  • Lowered cholesterol
  • Increased fat-burning efficiency 
  • Boosted athletic performance 

How do you assess aerobic capacity?

The most accurate method of assessing aerobic capacity is through a type of health and fitness test called the VO2 Max test.  

The VO2 Max test is a graded exercise test that measures your maximal oxygen uptake. The VO2 Max measures the maximum rate of oxygen that your body can use during intense exercise, measured in mL/kg/min. 

How does the VO2 Max test work?

The test takes approximately 20 mins to complete and can be carried out on either a treadmill or a stationary bike. The test-taker wears a face mask which measures the percentage of oxygen in inhaled and exhaled air throughout the test. 

After a warm-up, you will exercise at a gradually increasing intensity. This allows the test to assess how well your cardiorespiratory system adapts to working at different intensities. As you complete the test, you will reach a point at which your body transitions into working anaerobically – how quickly or slowly this occurs depends on how well your body processes oxygen during exercise.

Once your body hits this anaerobic threshold, you can continue to work at a higher intensity, but the amount of oxygen that is processed by your body won’t increase. Shortly after reaching the anaerobic threshold, you will reach your VO2 Max, after which the test will conclude with a cool-down period.  

What can a VO2 Max test tell me?

A standard VO2 Max test can provide data about your cardiorespiratory fitness, including your maximum heart rate, respiratory rate, anaerobic threshold, maximal oxygen uptake, and aerobic capacity.  

Depending on the equipment used, some more advanced VO2 Max tests will also be able to give you information about your training zones and how your body processes fats and carbohydrates. 

This information can be used to inform your training routine and how best you can work towards goals such as improving your aerobic capacity. 

How long does it take to improve aerobic capacity?

The length of time it’ll take you to improve your aerobic capacity and overall aerobic performance will depend on your training regime, your existing level of aerobic fitness, and the time you’re able to dedicate to working on your aerobic capacity. 

It’s typically recommended to re-test your VO2 Max after a period of 12 months – 6 months if you’re a professional athlete. This is to ensure you have sufficient time to train in a way that could lead to a marked improvement. 

How to improve your aerobic capacity with a VO2 Max test

Now that we’ve outlined what aerobic capacity is and how to test it, it’s time to look at how you can get started improving your aerobic performance. 

Step 1: Measure your baseline VO2 Max 

If you’re looking to improve your VO2 Max, you will first need an accurate measurement of your aerobic capacity at present. The best way to achieve this is through a VO2 Max test, which assesses your body’s ability to process oxygen during exercise. 

If you’ve already got a recent measurement of your VO2 Max, then you have the data you need to proceed to the next step. Otherwise, you can assess your VO2 Max by booking a VO2 Max test with a trusted provider or sports performance lab

If you don’t have access to VO2 Max testing, you can get a rough estimate of your aerobic capacity by completing a test such as the 12-minute run test or Beep test, neither of which requires any specialist equipment to complete. 

Some fitness trackers such as Garmin or Apple will have a predicted VO2 Max figure. How accurate this figure is will depend on how similar you are to the original population which was used to create the correlations. Unfortunately, because each company considers this a trade secret, it’s impossible to know how accurate these figures are unless we ‘calibrate’ them against a lab-based VO2 Max test.

Step 2: Train at a steady state to improve fat-burning

Low-intensity steady state (LISS) training involves maintaining a steady rate of exercise over a long period – for example, walking, jogging, swimming, or cycling at a rate you can easily maintain. 

In addition to lowering the risk of high blood pressure, stroke, and diabetes, LISS workouts are accessible for beginners and help to build endurance for higher-intensity workouts. Low-intensity workouts also tend to need less recovery time and enhance the body’s ability to use fat as a fuel source – which both promotes weight loss and allows the body to use carbohydrates as fuel at higher intensities efficiently. 

So, while they won’t directly improve your aerobic capacity, aerobic training workouts such as LISS can be a great way to pave the way to high-intensity workouts. 

Step 3: Incorporate high-intensity workouts to boost aerobic capacity

High-intensity workouts – such as HIIT (high-intensity interval training), running, speed walking, circuit training, sprint interval training, Tabata training, jump rope, and stair-climbing – are essential to increasing your aerobic capacity. 

High-intensity training that requires you to work at, or nearly work at, your anaerobic threshold, will help you to improve your VO2 Max by improving all the pathways by which your body takes on and processes oxygen. From your lungs getting better at taking in air, to your heart pumping more blood around your body, the effects of high-intensity exercise will improve all the systems responsible for producing energy for your muscles as you work out. 

One way of incorporating high-intensity training is through high-intensity interval training (HIIT), which incorporates short bursts of exercise punctuated with brief rest periods. These bursts of high-intensity exercise – performed at 80-90% of your max heart rate – have been shown to improve your aerobic capacity, improve blood flow, and lower your resting heart rate. 

If you’re trying to assess the intensity of a workout, a good rule of thumb t is the talk test – at a high-intensity level, you should only be able to speak a few words at a time.  

Step 4: Re-test after 6-12 months to assess improvement 

When it comes to checking in on your progress, wait at least 6-12 months before re-assessing your aerobic capacity with a VO2 Max test.

6 months may be an appropriate time frame if you’re training professionally, or have significant time and energy to dedicate to working on your cardiorespiratory fitness. Otherwise, 12 months is a great time to book a re-test and see the results of your hard work. 

Kickstart improving your aerobic capacity with a VO2 Max test at My Vital Metrics

Whether you’re an athlete looking to boost your cardiovascular performance or at the start of your fitness journey, getting an accurate assessment of your cardiovascular fitness is a great way to plan your next move.

Here at My Vital Metrics, we offer the gold standard in cardiovascular and body composition testing, designed to give you the data you need to unlock your body’s full potential. 

To get started with improving your aerobic capacity, reach out to My Vital Metrics to book a VO2 Max test or to schedule your free fitness and nutrition consultation today!