What Is Cardiovascular Endurance and How Do You Improve It?

If you've ever gone on a hike or a jog with a friend and felt like you were going to keel over after the first quarter mile while your companion was just getting started, you're probably eager to up your cardiovascular endurance game.

Not only can increasing your endurance boost your confidence when exercising with friends, but it can also improve your overall energy level and health.

Below, we explain what cardiovascular endurance is, why it's important and how to improve it.

Cardiovascular — or aerobic — endurance refers to how well your heart and lungs can deliver oxygen to your muscles during exercise, according to a July 2019 study in the ​International Journal of Environmental Research and Public Health​.

People who have high cardiovascular endurance "can exercise longer, not get tired as quickly and avoid all kinds of cardiorespiratory diseases," the July 2019 study states.

There are two ways to measure your cardiovascular endurance: METs (metabolic equivalent) and VO2 max.

Your VO2 max is your maximal oxygen consumption during exercise. In other words, VO2 max measures how efficiently your body uses oxygen.

There are a few different ways to calculate your VO2 max:

• Resting heart rate value
• 1-mile walk test
• 3-minute step test
• 1.5-mile walk or run test
• 2,000-meter indoor row

This online VO2 max calculator details how to use the above activities to find your VO2 max.

MET stands for the metabolic equivalent of an activity, and it measures how much oxygen you're burning while doing the activity. One MET is the amount of energy used while sitting quietly, according to Harvard Health Publishing, which means you aren't burning a ton of oxygen.

The more intense an activity is, the more METs the activity is, and the more oxygen you're burning. For example, running a 10-minute mile is equivalent to 9.8 METs. You can find a list of common activities and their MET values using the Compendium of Physical Activities.

Not only does having a high level of cardiovascular fitness mean you can exercise for longer periods of time without getting tired, but it's also associated with a lower risk of heart disease, various types of cancers and early death, according to a November 2016 research article in the journal ​Circulation​.

The good news is that you can improve your cardiovascular endurance with the following tips.

The best exercises for improving cardiovascular endurance are activities that elevate your heart rate and keep it elevated for a sustained period of time.

By elevating your heart rate with exercise, you strengthen your heart, improve blood flow, burn fat and improve your body's ability to deliver oxygen and energy to working muscles, which are the hallmarks of cardiovascular endurance.

It's worth noting there's no fastest way to improve cardio endurance, as building it takes time. But below, we list a few specific ways to build your cardiovascular endurance.

You can't build cardio endurance while you're sitting on the couch. If you've previously been sedentary or sporadic with your exercise routine, it's time to get up and get going. Any activity you do will start building endurance today. As you do more and more of it and increase your intensity, you'll continue to gain more endurance.

As a guideline, the U.S. Department of Health and Human Services recommends adults get at least 150 minutes of moderate- intensity exercise or 75 minutes of vigorous exercise each week.

Moderate-intensity cardio endurance exercises include walking, jogging or riding your bike at a leisurely pace. Vigorous cardio endurance exercises include running, rowing and cycling at a faster pace. For even greater benefits for your cardiovascular endurance, aim to get 300 minutes of moderate-intensity cardio exercise or 150 minutes of vigorous cardio exercise each week.

Here are a few cardio endurance exercise examples. There is no singular best way to build cardio endurance, but because you're less likely to stick to something you don't enjoy, it's important to choose activities you love and want to do on a regular basis.

• ​Walking:​ The key is to walk fast. To improve your cardiovascular endurance, your heart rate should be at least 60 percent of your maximum heart rate (MHR), which is calculated by subtracting your age from 220, according to the Mayo Clinic. To reach 60 percent of your MHR, you may have to walk from 3.5 to 4.5 mph.
• ​Jogging:​ A typical 154-pound person jogging at the relatively easy pace of 5 mph will burn twice as many calories in a half hour as the same person walking 3.5 mph, according to the ACE Fitness physical activity calorie counter. Because jogging is considered a more vigorous form of exercise, many people like to run to improve their cardiovascular endurance. The key to improving your cardiovascular fitness with jogging, as with any form or aerobic exercise, is to systematically increase either the amount you run each week or the speed at which you run by no more than 10 percent, per the Mayo Clinic Health System, or else you could risk overuse injuries. That means if you typically run 10 miles per week, increase by no more than 1 mile the next week.
• ​Swimming:​ The best way to improve cardiovascular endurance while swimming is to swim 50-, 100- or 200-yard intervals followed by short rest periods. As your endurance improves, increase the length of the intervals or shorten the rest periods.
• ​Cycling:​ Cycling should be done at a brisk pace if you want to improve your cardiovascular fitness. If you ride slower than 10 mph, according to the Centers for Disease Control (CDC), you will burn about as many calories as you would walking at 3.5 mph. At speeds greater than 10 mph, your heart rate will climb and your muscles will start demanding more oxygen and energy. Your cardiovascular and respiratory systems respond to the task, thus improving your fitness and endurance.
• ​Exercise machines:​ Stationary bicycles, elliptical trainers, rowing machines, treadmills and stair machines can all be used to improve your cardiovascular endurance. These machines enable you to adjust the intensity of the workout to meet your needs and you can also keep track of various biofeedback data, such as your heart rate or calories burned.

You can do anything for 30 seconds. That's the beauty of interval training. For 30 to 60 seconds, you push yourself as hard as you can go and then you get some time to recover. Alternating these periods of all-out effort with periods of recovery throughout your workout can get your heart rate up higher than you would be able to in a steady-state cardio workout.

This can have marked and expeditious effects on your cardio fitness. According to a study published in 2018 in the ​Journal of Strength and Conditioning Research​, just six sprint interval training sessions significantly improved endurance and aerobic capacity in trained runners. All participants improved their 3,000-meter sprint times and increased their times to exhaustion at 90 percent of maximal aerobic speed.

While you might not be at that level yet, you can still reap the benefits of including a few interval training sessions in your weekly workouts.

You can do interval workouts on the track or treadmill, on a bicycle or stationary bike and on a rowing machine or elliptical trainer. Warm up at an easy pace for five minutes; then increase your pace to your max effort. Hold it there for 30 to 60 seconds; then drop your pace back down for 30 to 60 seconds. When your heart rate and breathing stabilize again, drive the pace back up. Continue to alternate for about 20 minutes; then cool down.

Not only traditional cardio exercise can be used to improve endurance; your resistance-training routine can also be structured in such as way that it tests your muscular and your cardiovascular strength.

Unlike traditional weight training in which you do a set, rest, then do another set, circuit training has you moving from one exercise to the next with no rest between sets. For example, you would do a set of push-ups, followed by a set of squats, then mountain climbers, rows, thrusters and walking lunges. After a brief rest, you repeat the round one to four more times.

You can do each exercise for a set number of reps (8 to 12) or you can set a timer and do each exercise for 30 to 60 seconds. Perform as many repetitions of each exercise as you can in that time frame.

If you really want to test your heart and lungs, jump on the treadmill or stair climber for 30 minutes after your circuit workout.

Running may be your activity of choice, but you're not doing your cardiovascular system or the rest of your body any favors by only running. Doing the same activity all the time can lead to stagnancy in your fitness routine, and it can also lead to repetitive stress injuries.

That doesn't mean you can't run. It just means you should do other cardiovascular endurance activities too. Instead of running five days a week, run two days and then row or take an aerobics class on the other three days. This pushes your body in new ways to make it adapt to novel challenges.

Maybe you want to be able to run a mile without stopping, or run a marathon. In order to reach your goals, you have to set mini-goals. If you have a particular race or other competition in mind, find a training plan or a group of training partners to keep you on track.

Otherwise, think about a manageable 4-week program you can stick with, roughly mapping out your activities for the month. Keep track of how well you stick to the plan and how you feel during each workout. At the end of the month, assess how far you've come and revise your goals for the next month, adding in more cardio endurance workouts or aiming to increase your intensity.