What Counts as Aerobic Exercise? Here’s Everything You Need to Know About How to Get the Cardio You Need

Medically Reviewed
woman running outdoors wearing purple
Aerobic exercise ("cardio") makes you more efficient at delivering oxygen to the rest of the body, helping heart health, lung function, and more.Ivan Gener/Stocksy

Whether you call it aerobic, cardiovascular, or endurance exercise, you’re probably talking about the same thing: getting your heart pumping faster and oxygenated blood flowing, with the goal of improving your cardiorespiratory fitness. But it benefits more than just your heart.

The technical definition of aerobic exercise is: “Any form of exercise or activity that uses the aerobic metabolism — meaning oxygen is heavily involved in the cellular reactions that provide the body with the energy necessary to perform activity,” explains?Michael Jonesco, DO, an assistant professor of internal and sports medicine at the Ohio State University Wexner Medical Center in Columbus.?“You’re making yourself more efficient at delivering oxygen to the rest of the body.”

That means aerobic exercise makes the heart more efficient and capable of moving more oxygen-carrying blood with every beat. The lungs adapt to be able to take in more oxygen, and the muscles become more efficient at using oxygen.

Another way to think about aerobic exercise or “cardio” is that it's the type of workout where your heart rate and breathing increase, but not so much that you feel like you need to stop and rest after a short period of time. Think running, speed walking, stair climbing, cycling, and swimming, among other activities.

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Aerobic Exercises Boosts Heart Health and Your Entire Cardiovascular System

Cardiovascular fitness is defined by your capacity to exert yourself, says?Nicole Belkin, MD, chief of orthopedic surgery and rehabilitation and regenerative medicine at the NewYork-Presbyterian Hudson Valley Hospital in Cortlandt Manor, New York. “Regular physical activity trains the cardiovascular system to expand the level of demand and increase its capacity. This results in increased blood flow and blood volume to the heart.”

When you’re doing aerobic exercise, the cells throughout the body increase the number and size of the microscopic powerhouses of the cell called mitochondria, which use oxygen to create energy that can fuel important reactions throughout the body, Dr. Jonesco explains. Mitochondria make up the part of the body’s cells that turn oxygen into the energy each cell uses to function, according to The Cell: A Molecular Approach.

These changes yield major heart health benefits, with past research published in the?American Journal of Cardiology?showing that aerobic training is the most efficient mode of exercise for improving cardiovascular health.

Aerobic exercise can help lower your cholesterol, reduce your risk of?type 2 diabetes, improve immune function, and lower blood pressure, Jonesco says. And those heart benefits are important considering cardiovascular disease?is the leading cause of death for men and women in the United States,?according to the Centers for Disease Control and Prevention (CDC).

“The heart is a muscle that benefits from a workout just like any other muscle in the body. Aerobic exercise, which includes activities like brisk walking, running, swimming, and biking, conditions the heart to pump blood more efficiently to the whole body,” says Eduardo Sanchez, MD, MPH, chief medical officer for prevention at the American Heart Association.

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Aerobic Exercise Benefits Your Mood, Your Waistline, Your Posture, and More

The health benefits of aerobic exercise, however, don’t stop with you heart, says Dr. Sanchez: “Physical activity can help manage body weight, lower blood pressure, decrease ‘bad’ LDL cholesterol, improve blood sugar control, reduce stress, and improve sleep and memory.”

Here’s what the evidence shows:

  • Mental Health Benefits?Getting moving boosts your mood. In a study on 1.2 million people published in The Lancet Psychiatry in September 2018, exercisers enjoyed about 1.5 days fewer of poor mental health compared to nonexercisers.

    While all exercise improved mood, the biggest benefits came from team sports, cycling, gym and aerobic workouts. Aerobic exercise has been shown to reduce the risk of?anxiety?and?depression in adults; it helps people manage stress via sleep and mood-regulating benefits, according to the Anxiety and Depression Association of America (ADAA).

  • Weight Loss Benefits?Aerobic exercise burns up calories, which in combination with a healthy diet can help you shed excess weight, Jonesco says. Aerobic exercise also tones your muscles and improves posture.
  • Fitness Benefits?Aerobic exercise (over time) gives you more energy to work out. By improving your body’s ability to take in and use oxygen for fuel, aerobic exercise can increase your stamina, giving you more energy for both work and play, Jonesco adds.
  • Bone and Joint Benefits?Moderate- or vigorous-intensity aerobic exercise like running or jumping rope can help increase bone density in older individuals and for those with?osteoarthritis?or other?rheumatic?conditions, notes the U.S. Department of Health and Human Services (HHS).

  • Brain Health Benefits?Physical activity has also been linked to lower risk of dementia, and may improve cognition as you age.

Guidelines Say You Should Be Getting Some Aerobic Exercise Most Days, and More If You Can

According to the Physical Activity Guidelines for Americans?published by the U.S. Department of Health and Human Services in 2018 (the most recent), aerobic exercise varies by three components:

  • Intensity, or how hard a person works to do the activity, such as moderate (the equivalent of brisk walking) and vigorous (the equivalent of running or jogging)
  • Frequency, or how often a person does aerobic activity
  • Duration, or how long a person does an activity in any one session

According to the HHS, adults should aim to get 150 minutes to 300 minutes of moderate physical activity or 75 minutes to 150 minutes of vigorous-intensity aerobic physical activity a week. The HHS notes that it is preferable to spread this activity throughout the week on most days.

In addition to this recommendation for aerobic exercise, the HHS recommends performing balance and stretching activities to enhance?flexibility?as well as?muscle-strengthening workouts?two or more times a week.

The World Health Organization (WHO) also recommends the same duration of weekly aerobic exercise, according to recommendations published in 2020.

RELATED:?New Physical Activity Guidelines Say We Should Be Moving All Day Long

Yet data published in the HHS guidelines report shows that nearly 80 percent of adults are not meeting the key standards for both aerobic and muscle-strengthening activity, which contributes to 10 percent of premature mortality.

Types of Aerobic Exercise and How to Get Started

Before beginning any exercise program, especially if you have heart or other health issues, talk to your doctor.

If you’re not doing much aerobic exercise at all currently, Sanchez says: “Start small and work your way up.”

He suggests building in opportunities for movement throughout the day, such as a 10-minute break to walk or do a few jumping jacks. Many people find success in focusing on walking as their exercise and gradually increasing time spent walking to get up to the recommended 30 minutes per day on most or all days of the week, says Sanchez.? Over time, as you improve your aerobic fitness, you will be able to increase your exercise intensity.

As the names would imply, the difference between moderate-intensity exercise and high-intensity exercise is in the?intensity?of the workout, or the degree to which you’re pushing yourself.

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How to Do Moderate-Intensity Aerobic Exercise

You’re exercising at a moderate intensity if you can keep up a conversation during the activity. If you can get out three or four sentences in a row without gasping for air, it’s a sign that you’re maintaining an intensity that is truly aerobic, meaning aerobic metabolism is supplying the vast majority of your body’s energy, Jonesco says.

Your heart rate should be roughly 60 percent of your maximum heart rate. To find your max heart rate, subtract your age from 220. Multiply that number by 0.6 to obtain your target heart rate for moderate-intensity aerobic exercise, Jonesco says.

How to Do High-Intensity Aerobic Exercise

If you’re healthy and have already built up a base level of aerobic fitness, you can shoot for a higher target heart rate, up to 80 or even 90 percent of your maximum heart rate, Jonesco says.

At this intensity, you will likely be able to say a couple of words before needing to gasp for air. You may not be able to talk at all. Keep in mind, however, that intensity predicts duration, so you won’t be able to keep up this intensity for as long as when you’re exercising at lower intensities.

High-intensity interval training — alternating between bouts of all-out effort and low-intensity recovery — is a great way to improve cardiovascular fitness when you’re short on time, Jonesco adds.

Examples of Aerobic Exercises

You have lots of options when it comes to getting your aerobic exercise in. Walking, biking, hiking, dancing, and gardening are all great forms of aerobic exercise that you can easily integrate into your day and can yield big benefits even if you’re doing them in small spurts.

A study published in the?European Journal of Applied Physiology in October 2015 showed that exercisers who broke their aerobic workouts into 10-minute bouts throughout the day improved their arterial stiffness, a marker of cardiovascular health, even more than those who performed the same amount of daily aerobic exercise, but all at once.

The thinking has also changed somewhat on whether there’s a threshold minimum workout duration required to reap cardiovascular health benefits from aerobic activity. The most recent HHS physical activity guidelines eliminated the long-standing recommendation that exercise had to last at least 10 minutes to count toward your daily total. The new guidelines emphasize that small bouts of activity throughout the day can add up to big health benefits.


Additional reporting by K. Aleisha Fetters, Nicol Natale, and Jessica Migala.

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