What Is Cardio? A Complete Guide To Cardio + Why You Should Do It


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We often receive the message that cardio exercise is important and should be part of our lives, but what is cardio exercise?

If you are a beginner, you might not know what constitutes cardio exercise or a cardio workout, and if you do not have a good working definition of cardio exercise, it’s nearly impossible to know where to start with your fitness plan.

In this cardio exercise guide, we will cover not just the basic cardio definition and what qualifies as cardio exercise but also helpful tips and examples of cardio workouts that can be appropriate for beginners and fit individuals alike.

We will cover: 

  • What Is Cardio Exercise?
  • What Qualifies As Cardio Exercise?
  • How Much Cardio Exercise Do I Need to Do?
  • Benefits of Cardio Exercise
  • Examples of Cardio Workouts
  • 7 Tips for Doing Cardio Exercise

Ready? Let’s dive in! 

People dancing in a Zumba class.

What Is Cardio Exercise?

Cardio exercise, also commonly referred to as aerobic exercise, is any type of physical activity that increases your heart rate such that it challenges and strengthens your cardiovascular system.

The term “aerobic“ means “with oxygen,” so cardio exercise involves exerting yourself to an intensity level where you can still breathe (even if rapid and deep) enough to take in the oxygen your muscles need to produce energy for the movements you are performing.

This is in contrast to “anaerobic” exercise, in which the intensity is so high that you are fairly breathless, requiring your muscle cells to produce energy via anaerobic glycolysis and other metabolic pathways that do not require oxygen.

Cardio workouts can entail any number of modes of exercise, such as brisk walking, running, cycling, swimming, rowing, hiking, stair climbing, elliptical machines, and rollerblading.

Now that we have the cardio definition clear let’s check out what exactly qualifies as “cardio.”

A person jumping up stadium stairs.

What Qualifies As Cardio Exercise?

The purpose of a cardio workout is to increase your heart rate and respiration in order to strengthen the heart muscle and improve the efficiency of the cardiovascular system as a whole, but what counts as cardio exercise?

According to the American College of Sports Medicine, the low-intensity cardio zone falls between 57-63% of your maximum heart range.

The moderate-intensity cardio zone corresponds to a heart rate range of 64-76% of your maximum heart rate, while vigorous-intensity cardio is associated with a heart rate of 77-95% of your max.

These cardio zone classifications vary slightly from those provided by the Centers for Disease Control and Prevention (CDC), which only defines two cardio zones. According to the CDC, moderate-intensity cardio exercise increases your heart rate to 50-70% of your max, while vigorous cardio exercise elevates your heart rate to 70-85% of your maximum.

Therefore, any type of physical activity that can increase your heart rate to at least 50% of your maximum heart rate can count as a cardio workout.

A person on a treadmill.

How Much Cardio Exercise Do I Need to Do?

Most people want to know how much cardio exercise they should do to support health and reduce the risk of disease.

The reason why the different designations of cardio-intensity zones are important is that there are different guidelines for how much physical activity you need to do from either category of cardio-exercise intensity to reduce your risk of lifestyle diseases.

The guidelines for physical activity for adults set forth by the Centers for Disease Control and Prevention and the British Heart Foundation are to accumulate either 150 minutes of moderate-intensity aerobic exercise or 75 minutes of vigorous-intensity cardio exercise per week.

For this reason, it can be helpful to wear a heart rate monitor during your cardio workouts to quantify your effort level and the physiological impact of your workout.

In terms of meeting these aerobic exercise guidelines, you have to figure out how you divide up your cardio exercise workouts over the week in terms of frequency, duration, and intensity.

For example, if you want to do only moderate-intensity cardio exercise, you can do five 30-minute workouts per week or three 50-minute workouts, and so on.

If you prefer vigorous cardio exercise, you can do three 25-minute sessions per week or four 20-minute workouts, among any number of other divisions.

It is also possible, and usually preferable, to do a mix of both moderate-intensity cardio exercise and vigorous-intensity cardio exercise.

For example, you could do four 25-minute moderate-intensity cardio workouts per week (totaling 100 minutes or 2/3 of the requisite amount) and one 25-minute vigorous-intensity cardio workout (1/3 of the vigorous cardio requirement) to satisfy the guidelines.

Two people running down a coast.

Benefits of Cardio Exercise

There are many physical and mental health benefits of cardio exercise, including the following:

  • Strengthening the heart and lungs
  • Burning calories and supporting healthy weight loss
  • Decreasing stress and anxiety
  • Increasing endurance
  • Increasing muscular strength and endurance
People on spinning bikes at a gym.

Examples of Cardio Workouts

Keep in mind that any type of physical activity that can elevate your heart rate to the appropriate level (roughly 57-76 percent of your maximum heart rate, depending on the guidelines you follow) can be considered a cardio workout, so it is often best to choose the type of exercise that you enjoy most.

This will help optimize exercise adherence and make it easier to stick to your training plan.

It’s also beneficial to include some variety in the types of cardio exercise you do in a week, as different activities challenge your muscles and joints in different ways, leading to better functional strength and decreasing the risk of overuse injuries.

Here are some examples of modes of exercise that work well for cardio workouts:

  • Running inside on a treadmill or outdoors
  • Cycling indoors or outdoors
  • Walking or hiking, Nordic walking, incline walking
  • Rowing
  • Swimming, deep water running
  • Elliptical machine, stair stepper machine
  • Rollerblading
  • Cross-country skiing, snowshoeing 
  • Jump roping
  • Calisthenics 
  • Stand-up paddle boarding, kayaking 
  • Zumba or high-paced dancing
A person on a rowing machine.

7 Tips for Doing Cardio Exercise

The following tips can be useful for beginners who want to know how to get started with cardio exercise:

#1: Wear a Heart Rate Monitor 

As mentioned, the best way to quantify the intensity of your cardio workout is to wear a heart rate monitor. 

This will help you know whether you are doing moderate-intensity cardio exercise or vigorous-intensity cardio exercise. 

Additionally, you can use your exercise heart rate data to look at your improvements and fitness over time. As you get in better shape, the heart rate that corresponds to a submaximal level of cardio exercise should decrease, and the time it takes your heart rate to return to resting levels after you are done exercising should decrease as well.

#2: Start Small

Start with short, lower-intensity cardio workouts lasting 10-20 minutes, and slowly build up the length and intensity as you get fitter.

Even just getting out for a brisk walk in the morning or after dinner can be a great way to get started with cardio exercise.

A person on a stationary bike.

#3: Work Out With a Friend

Cardio exercise can be monotonous if you are using a stationary exercise machine and working out at a steady-state effort.

Recruit a friend to work out with you or try outdoor exercise, listening to music or podcasts, or joining a group exercise class to increase motivation and enjoyment.

#4: Consider Buying At-Home Cardio Exercise Equipment

Depending on your budget, outfitting your home with some cardio equipment can be a great way to make cardio exercise more convenient and sustainable. 

However, if you are just getting started on your fitness journey, it’s usually a good idea to experiment and see what type of exercise you enjoy most before investing in expensive exercise equipment.

Good options for at-home cardio exercise equipment include a treadmill, elliptical, indoor cycling bike, or hybrid trainer like the Bowflex Max Trainer M9.

A person jump roping, an example of what cardio is.

#5: Try a Fitness App 

There are tons of fitness apps that have free or paid streaming workouts and activity tracking to keep track of your workout routine and give you guidance along the way. Examples include Peloton Digital, Strava, MyFitnessPal, and JRNY.

#6: Join a 30-Day Fitness Challenge

A 30-day fitness challenge can be a great way to help you establish a consistent exercise routine and get started with sustainable cardio exercise. 

Consider a jump roping challenge, running challenge, walking challenge, or just a mile-a-day challenge.

#7: Mix It Up

Add variety to your routine with different types of cardio exercise to keep things fresh and fun while advancing your fitness.

Congratulations on taking a big step in your fitness journey by embarking on cardio exercise. You can even start today with one of our 30-Day Fitness Challenges!

You’ve got this!

A person running.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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