What Is Aerobic Capacity? How to Measure and Improve Your Cardio Fitness

Whether you’re a fitness newcomer or an endurance athlete looking for ways to perform better, gauging your fitness level is crucial. Doing so gives you a starting point from which you can improve, and it can guide your workouts to meet your specific exercise goals. It can also help you identify what types of exercise you excel at and where you need some work.

Measuring how fit you are usually involves several different parameters. These include how much muscular strength you have, your body composition and flexibility, how much strain your muscles can endure, and your aerobic capacity. In this guide, we’ll focus on aerobic capacity – a measurement of how much oxygen your body uses during exercise. You’ll learn why it matters, how to measure it, and discover ways to improve it. 

Note: The information in this article is the opinion of the article’s author and does not represent the opinion of Biostrap or its affiliates. This article is for informational purposes and is not intended as a substitute for medical advice. Please consult a qualified professional if you require medical attention.

What Is Aerobic Capacity?

Aerobic Capacity: Woman jogging on a trail

Aerobic capacity, also known as cardiopulmonary capacity, cardiorespiratory fitness, or VO2 max, is a measurement of your maximum oxygen consumption during physical activity. It’s a reflection of your aerobic power and your body’s ability to keep performing under strenuous activity for longer periods of time. 

Here’s the science behind it: As you exercise, your lungs draw in oxygen and transfer oxygenated blood to your heart, cells, and muscle groups throughout your body. The oxygen-rich blood pairs with glucose to trigger the production of ATP (adenosine triphosphate) — an organic compound that helps your working muscles contract. This process enables you to run long distances, swim laps, and ride your bike.

Why Aerobic Capacity Matters

Your aerobic capacity is a reflection of your overall health. While maximal oxygen uptake can decrease with age, it can also diminish when you stop exercising regularly or when you get injured. Aerobic capacity is important because it can help you stay healthy and active. In fact, aerobic exercise can help build muscle mass, support skeletal muscle health, and may reduce blood pressure in people with hypertension.

Having poor aerobic capacity can also impact your heart health. Research links poor aerobic capacity with a greater risk of heart disease in certain individuals. Studies also show that VO2 max increases with aerobic exercise compared to moderate activity, and both are beneficial to heart health in patients with cardiovascular disease.

Measuring your aerobic capacity also allows you to see how well your body performs aerobic or endurance exercises. The more you work on your cardiovascular endurance, the higher your aerobic capacity or maximum oxygen uptake will be. This means you’ll be able to work harder and longer as your aerobic capacity increases.

How to Measure Aerobic Capacity

Doctor oversees an aerobic capacity test

There are two main methods to measure your VO2 max: fitness tests or mathematical estimations. Fitness tests are more accurate since they track your oxygen intake during a specific exercise in a controlled environment. On the other hand, there is a standard equation you can use to get a rough estimate of your aerobic capacity. Here’s how each method works.

Fitness Test

The VO2 max test is usually conducted in an exercise lab and can also be measured at some gyms. During the test, you run on a treadmill or ride a stationary bike while wearing a mask. The mask measures the amount of oxygen you breathe in during the exercise testing. Intensity increases throughout the test until you reach the point of exhaustion. 

These tests may also monitor your lactate threshold — the point at which your body switches from aerobic to anaerobic processes. Anaerobic exercise occurs when your body needs to use other energy sources besides oxygen — such as lactic acid — to continue performing. If your VO2 max test includes lactate threshold testing, you’ll have blood drawn every few minutes to measure oxygen levels in your blood cells.

VO2 Max Formula

While elite athletes often get VO2 max tests regularly, the tests themselves can be expensive since they’re monitored by a doctor in a laboratory setting. That doesn’t mean you can’t figure out your VO2 max if you’re not an endurance athlete. Fortunately, physiologists have created a formula using factors that typically impact cardiovascular endurance to help estimate your oxygen intake during exercise. Some formulas don’t require any exercise testing while others are based on your performance during aerobic exercise at low intensity and moderate intensity .

VO2 max usually decreases with age, but your maximum heart rate and resting heart rate also play a role in your cardiovascular performance. Here are a few formulas you can use to gauge your aerobic capacity. 

  • Heart Rate Metrics Formula: VO2 max = 15.3 x (maximum heart rate / resting heart rate)
  • Rockport Walking Fitness Test: VO2 max = 132.853 – (0.0769 x your body weight in lbs) – (0.3877 x your age) + (6.315 if you’re a male or 0 if you’re a female) – (3.2649 x the time it takes you to walk 1 mile briskly) – (0.1565 x your heart rate at the end of the 1-mile walk). 
  • Brigham Young University Jog Test
    • Women: 100.5 – (0.1636 x weight in kg) – (1.438 x the time it takes to lightly jog 1 mile) – (0.1928 x heart rate at the end of the jog)
    • Men: 108.844 – (0.1636 x weight in kg) – (1.438 x the time it takes to lightly jog 1 mile) – (0.1928 x heart rate at the end of the jog)

The walking and jogging tests are submaximal field tests. This means you shouldn’t be working at your maximum cardiovascular or respiratory output. The pace should be challenging, but not an all-out intense effort. The run test is ideal for kids and healthy adults while the walking test is a better choice for adults who are out of shape or recovering from injuries.

How to Improve Aerobic Capacity

Aerobic capacity: Cross-country skiers on the trail in Bavaria

The most effective way to boost cardiovascular fitness is to incorporate high-intensity endurance training into your regimen. High-intensity interval training (HIIT) is the ideal option when trying to increase your VO2 max. These exercises are usually preceded by a warmup and consist of intense cardio exercises such as sprints, jump lunges, and calisthenics. Each cardio exercise is followed by a brief rest period.

During high-intensity aerobic activity your cardiac output increases as your body demands more oxygen to keep performing. When you repeat these exercises regularly over time, your aerobic capacity will increase.

Any type of regular exercise will improve your aerobic capacity. If you can’t do high-intensity exercise or prefer strength-training exercises, start with aerobic activities like walking, swimming, or light jogging instead. You can increase the exercise intensity as your fitness level improves and start incorporating higher intensity exercises into your aerobic training.

Improve Aerobic Capacity With Biostrap

Aerobic fitness is a key metric that can help you reach your fitness goals whether it’s weight loss or conquering an endurance race. When it comes to tracking metrics, there’s no better way to monitor your health than using a wearable tracker like Biostrap

With Biostrap, you can track aerobic metrics including your oxygen saturation levels as well as heart rate variability during each exercise session. You’ll also find useful tips on our blog including how to optimize your cardio routines and hack your fitness.

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