What Exactly is Aerobic Exercise, and Why Should You Add it to Your Workout Routine?

The phrase 'aerobic exercise' likely conjures up images of jazzercise classes or your mom's Denise Austin workout videos. Or maybe you've been using the term synonymously with cardio. For the most part, all those guesses are correct, but aerobic exercise can get a little more complicated than that—and really, it boils down to the intensity of your workout.

So what, exactly, is aerobic exercise, and which workouts count as such? To help you decode all that training lingo, we spoke to experts who break it down so you can build aerobic exercise (and its counterpoint, anaerobic exercise) into your workouts. Learn exactly what these words mean for your fitness—and for your health.

What is aerobic exercise?

When you do aerobic exercise, you move your large muscle groups (think legs, glutes, and core) at the same time, usually in a rhythmic way, and for an extended period of time, explains Michele Olson, PhD, CSCS, senior clinical professor of sports science at Huntingdon College in Montgomery, AL. "Your respiration goes up, as does your heart rate to about 60 to 90 percent of your maximum heart rate, but not over that max," Olson says.

All aerobic exercise counts as cardiovascular activity, which is why you'll often hear "cardio" used in placed of "aerobic." (FYI, though, not all cardio exercise is aerobic but more on that below.) So, you can label activities like running, swimming, cycling, and even speed walking as aerobic exercises.

The key to making movement aerobic: "You need to be able to sustain the activity for more than two minutes with sufficient oxygen intake," explains Noam Tamir, CSCS, owner of TS Fitness in New York City. That means even as your breathing rate increases, you shouldn't find yourself gasping for air. "The intensity is usually light to moderate, so you're able to continue for about 30 to 60 minutes without spiking your heart rate significantly."

While most aerobic activity fits in the low- to moderate-intensity category, there are different levels. "Low-intensity aerobic exercise builds endurance, such as brisk walking or maybe a dance-inspired group fitness class," explains Olson. This would hit that lower heart-rate range, say around 60 to 70 percent of your max heart rate. Moderate-intensity aerobic work would involve a heart rate level between 70 and 80 percent of your max and could include workouts like step aerobics and jogging. Finally, high-intensity aerobic workouts elevate the heart rate between 80 to 90 percent of your max. For this, you might do spinning, faster running, or jogging stairs. It stops short of going at an all-out effort, though.

What's the difference between aerobic and anaerobic exercise

To sum it up, aerobic activity involves your sustained physical effort that's typically between 30 and 60 minutes, where your heart rate remains at a steady 60 to 90 percent of your max. You're able to inhale and exhale steadily and sustain your pace because the oxygen you're taking in is sufficient. (Aerobic literally means "in the presence of oxygen.") Aerobic exercise is more about duration and less about the intensity, Tamir says. "Your body is using both fatty acids and carbohydrates as fuel to be able to sustain the submaximal effort level," Olson adds.

Anaerobic exercise, on the other hand, is where that max effort comes into play. It's another form of cardio in which you should only be able to sustain activity for about 30 seconds before you need a break. It should feel pretty difficult for you to catch your breath while you're doing this type of training (anaerobic meaning "the absence of oxygen"). Explosive exercises like plyometrics, sprinting, and even heavy weightlifting are all examples of anaerobic exercise. "The body uses phosphocreatine and carbohydrates as fuel [for anaerobic exercise] because they can be broken down rapidly," Olson explains. "Fats take too long to break down as an energy source."

Interval training and circuit classes offer strong examples of activities that usually involve both anaerobic and aerobic fitness. "In these classes, you push to your max for brief periods of time, followed by lower intensity breaks," explains Olson. "This improves both your anaerobic fitness and power performance, as well as keeping your aerobic fitness in tact."

What are the health benefits of aerobic exercise?

Cardio days provide some of the best days for your cardiovascular system (hence the name), but benefits go beyond that of the heart. "Aerobic activity lowers your blood pressure and blood lipids, and normalizes your blood glucose," explains Olson, all of which will help you live longer and lower risk of conditions like diabetes.

Tons of research backs up these aerobic advantages, which is why the American Heart Association recommends people get 150 minutes per week of moderate-intensity aerobic exercise. In addition to fighting off risk of heart disease, diabetes, and high blood pressure, it can also help keep your brain sharp, better your bones (even more so if you do it often and add a little impact), and battle depression.

Plus, the more aerobic activity you do, the better you'll get at it. Aerobic training can increase the size and strength of your slow twitch muscles—those involved in longer, sustained workout efforts like long-distance running. It can also improve your VO2 max, a major marker of fitness level which reveals how much oxygen your body can take in and utilize. With all that comes enhanced endurance, Tamir says—in everyday life, getting regular aerobic exercise also simply means you can jog to catch your bus or walk for miles without feeling super tired.

How to do an aerobic workout at home:

While common aerobic activities include jogging, swimming, cycling, rowing, and brisk walking (just to name a few, of course), circuit workouts work too. "All you have to do is perform at the required heart rate and intensity levels so that you're able to maintain it for an extended period of time," says Tamir.

If you don't feel like going outside or even leaving your house, but still want an aerobic workout, there's a perfect solution: this bodyweight routine from Tamir. Do the 12 exercises below in order for 30 seconds each and 5 rounds, with as little rest as possible between exercises:

1. High knees
2. Mountain climbers
3. Butt kickers
4. Walkouts/inchworms
5. Alternating bodyweight reverse lunges
6. High skips
7. Bodyweight squats
8. Lateral hops
9. Walking lunges
10. Jumping jacks
11. Crunches
12. Toe taps to a block or step

Something to remember while performing this circuit: Work at a moderate intensity, so going from move to move sans breaks shouldn't feel too challenging. If you do need a break, go a little slower. You'll get better each time you do it.