Should You Do Aerobic or Anaerobic Exercise—and What's the Difference?

Exercise might be your pastime, but it’s also a bit of a science. And there are few fitness topics that throw you right back to middle school science class faster than aerobic vs. anaerobic exercise.

The distinction between the two can be a little confusing, because you can have bursts of anaerobic exercise during an aerobic workout. But after this deep dive into aerobic and anaerobic activity, you’ll be armed with all the info you need to add both to your exercise routine.

What Is Anaerobic Exercise and How Does It Work?

First, a little science refresher: “Your body is always creating energy (called adenosine triphosphate or ATP) with and without the use of oxygen,” says Peloton Instructor Matt Wilpers. Energy created aerobically, or with oxygen, is easier for your body to replenish, compared to energy created anaerobically, or without oxygen, he says.

Different types of exercise and activity draw on those different sources of energy. “Exercise with energy demands that can be met primarily by aerobic energy pathways are typically more sustainable for a prolonged period of time than exercise with energy demands that exceed what can be provided by aerobic energy pathways, thus requiring additional energy from anaerobic pathways,” Matt says. “Therefore, anaerobic exercise is typically considered to be more intense and explosive than aerobic exercise, as the energy demands far exceed what the aerobic energy system can replenish in order to keep the effort going.”

To do that, anaerobic exercise uses glycogen (a form of glucose or sugar) stored in your muscles to fuel your movement without oxygen, says Schuyler Archambault, physical therapist and owner of Arch Physical Therapy and Fitness.

It’s probably not too surprising to learn you can’t sustain long periods of activity without oxygen, so you’re typically only in a state of anaerobic exercise for seconds, maybe up to a couple minutes, Archambault adds. “It's super fast and gets super intense.” 

But the two energy systems work together: You can have bursts of anaerobic activity during an aerobic workout, Archambault says, such as during interval training or a Fartlek run. “If you’re picking up the intensity for a short bout and going really hard with it, you’ll end up kicking on your anaerobic system,” she says. “It's not so black and white, where this whole run is [aerobic] and this whole run is [anaerobic].”

The Benefits of Doing Anaerobic Exercise

You don’t have to do anaerobic exercise; there are plenty of benefits of steady jogs, long cycling rides, and intermediate strength-training classes (more details on those below). But adding some short bursts of higher-intensity work can pay off.

You’ll Clear Lactic Acid Faster

When you use your anaerobic system, lactic acid builds up in your muscles. But the more you work this system, the more your body adapts to the work (just like with any form of exercise) and grows stronger. In this case, you improve what’s called your lactate threshold, meaning your body can clear the lactic acid faster and give you more time before you feel any negative effects like fatigue. “It allows you to basically build up more of that lactic acid before you're feeling that soreness and heaviness in your legs,” Archambault says.

You’ll Build Power

When you’re serious about lifting weights, you might be looking to improve your one rep max, or the heaviest weight you can lift in a certain exercise for just a single repetition. Your anaerobic system will power you through that massive deadlift or killer squat, says National Strength and Conditioning Association (NSCA) board member and Grand Canyon University Fitness Programs Coordinator, D’Annette Stephens. The more you practice, the more powerful you’ll become over time as your body adapts.

Even if you’re a beginner, you’ll build power through anaerobic exercise: Consider a push-up, Stephens says. If you can only do one now, it will take you just a few seconds and require an intense effort. But as you keep at it and build muscle, power, and endurance, you’ll be able to do more reps.

Your Bones Will Grow Stronger

Some anaerobic exercise, like plyometrics and heavy weight lifting, helps protect your bone health, Archambault says. High-impact, weight-bearing activities such as jumping exercises put even more healthy strain on your bones than lower-impact options like walking, encouraging bones to grow stronger, according to the American Academy of Orthopedic Surgeons. Strength-training exercises primarily build muscle but also build bone too, per the AAOS. “Anaerobic exercise is at a higher intensity and therefore recruits more muscle fibers to stress and stimulate strength and power,” Matt says. One of the many benefits of this is improving the musculoskeletal system, according to Matt.  

Examples of Anaerobic Exercises

You can access your anaerobic system doing any type of exercise as long as you suddenly bump up the intensity for short periods of time. Here are a few examples of what that might look like.

HIIT Classes 

HIIT, or high-intensity interval training, pushes your heart rate to the threshold where you’ll trigger your anaerobic system, Archambault says, especially if the exercises include plyometrics or jumping movements. You can find HIIT workouts that fit the bill on the Peloton App.

Cycling Classes

If your cycling class includes sprints, uphill surges, or other short bursts of higher-intensity work, you’ll get some anaerobic energy burn going. Try a Tabata cycling workout on the Peloton App to really get your heart racing.

Weight Lifting

Lifting a heavy weight takes just a few seconds and requires a lot of force and power. The lifts that get you a little out of breath are anaerobic, Archambault says. Look for a Strength class on the Peloton App that pushes you.

Sprinting 

Sprinting is the classic example of anaerobic exercise, Stephens says. Try an interval running workout on the Peloton App to get plenty of those short bursts at higher speeds, or try hitting the track for a friendly competition with your running buddy.

Any Sudden, Intense Movement

While it’s not exactly exercise, it is still anaerobic activity to, say, suddenly jump out of your desk chair because you forgot your phone upstairs and race up the two flights to retrieve it. Other similar movements throughout your day might spark some anaerobic work even without being in an exercise setting, Stephens says.

What Is Aerobic Exercise?

Think about aerobic exercise like cardio exercise: You’re using oxygen to power your muscles during longer, lower-intensity workouts from the air you breathe, rather than relying on stored sources of energy. “Aerobic training is sustained by the heart pumping sufficiently oxygenated blood to the working muscles in order for energy reserves to be replenished as they are used,” Matt says. Because you’ve got an infinite supply of oxygen to replenish your muscles with, you can generally sustain aerobic activity for a lot longer than anaerobic activity.

Aerobic Exercise Benefits

Considering aerobic exercise is essentially cardio, it’s got loads of benefits. Here are a few of the biggies.

Your Heart Will Grow Stronger

Cardio exercise gets its name from the cardiovascular system, aka having to do with your heart and blood vessels. Aerobic activity “exercises the cardiovascular and respiratory systems, which create a number of results, including a stronger heart,” Matt says.

In fact, “aerobic activity lowers blood pressure, increases your HDL cholesterol, and helps reduce your risk of heart disease,” Archambault says.

Your Mental Health Will Improve

Ever heard of the runner’s high? Aerobic exercise releases feel-good brain chemicals called endorphins that lift your mood. Regular exercise is even linked to a lower chance of developing depression.

You Could Avoid Several Serious Health Problems

There’s a long list of conditions and illnesses that are less likely in people who exercise regularly other than heart disease, including osteoporosis, type 2 diabetes, COVID-19, the flu, and even some types of cancers, according to the CDC.

Anyone Can Try It

Just about anyone can find a form of aerobic exercise that’s comfortable and safe for them and that they enjoy doing (take a look at the examples below if you need some suggestions). That makes it a little more accessible than anaerobic exercise, which really requires pushing yourself toward your upper limits, Archambault says.

Aerobic Exercise Examples

Think of aerobic exercise as any cardio you’re doing for longer than a couple of minutes, Stephens says. 

With that in mind, the list of examples of aerobic exercise can be pretty extensive, she says, including:

How Often Should You Do Anaerobic and Aerobic Exercise?

For overall health and wellbeing, stick to the physical activity guidelines for American adults from the U.S. Department of Health and Human Services, Matt says: At least 150 to 300 minutes a week of moderate-intensity cardio exercise, or 75 to 150 minutes a week of vigorous cardio exercise, plus two strength training sessions.

That might look like 60 minutes of moderate-intensity cardio five days a week, 15 minutes of intense cardio five days a week, or any other combination in between. No matter how you break up those minutes, some of your vigorous activity is “probably going to fall into the category of anaerobic, but isn't exclusively anaerobic,” Archambault says, because again, anaerobic exercise isn’t sustainable for long.

The timing and programming of your workouts will depend on your training goals, and you can ramp up either aerobic or anaerobic exercise (or both), Matt says.

Keep in mind you generally need more rest when you’re doing more anaerobic exercise, Archambault says. That applies to rest days during your week, but also to rest periods within a workout. For example, if you’re sprinting, you might need a “one-to-one ratio of sprint to rest in order to fully recover,” Archambault says. In other words, you might sprint for 60 seconds, rest for 60 seconds, and repeat several times.

If you’re new to high-intensity, high-impact anaerobic training, ease into it by starting with one to two days of more vigorous exercise a week on non-consecutive days, Archambault says. “You will want a day or two in between those sessions so you can fully recover, because the goal of these sessions is to be able to go all out,” she says. When you’re just starting out, back-to-back intense workouts of any kind could leave you feeling more sore and fatigued, which is a recipe for burnout and injury.

And always make sure to warm up before banging out some anaerobic work. Remember, the goal is to give it your all-out effort, Stephens says, which isn’t usually the first thing you want to do in a workout. “You shouldn’t just walk into the gym and do a 250-pound deadlift,” for example, she says. “Everything should be a build up.” Without preparing your body first, your form and performance could suffer and you could get hurt.

Aerobic vs. Anaerobic Exercise: How to Pick Which One Is Right for You

So how do you know if anaerobic or aerobic exercise is right for you? To find your answer, think about how you’re tapping into that energy system, Archambault says.

Everyone should do full-body strength training, and lifting weights will likely have some anaerobic aspect to it, even for beginners. But high-intensity cardio like sprinting or high-impact plyometrics might not be right for everyone. “It really depends on your injury history, your goals, and [whether] you have any underlying diseases that you might have to be a little bit more careful of,” she says. It’s always a good idea to touch base with your doctor before starting any new kind of exercise or ramping up your intensity.

The Takeaway

Anaerobic vs. aerobic exercise refers to the different energy systems your body uses to power different types of workouts. Aerobic exercise uses oxygen to fuel longer, lower-intensity activity, like jogging, while anaerobic exercise uses glycogen instead of oxygen for short-term, powerful bursts of activity, like sprinting.

Everyone can—and should!—find safe ways to do both, but how much anaerobic exercise you do depends on your goals. If you want to build speed and power, such as improving your 100-meter dash time or upping your deadlift one rep max, you’re going to need to do more anaerobic work. When you do, make sure you’re still giving yourself plenty of time to rest and recover from those intense efforts.

This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.