Aerobic vs. Anaerobic Exercise: What’s the Difference?

To the untrained ear, the terms “aerobic” and “anaerobic” sound like some fitness mumbo jumbo only an exercise physiologist needs to know. Actually, anyone who hits the pavement, pool, studio, or strength room—or wants to—should know. That’s because all types of workouts in the world fall under one of these umbrella terms or another.

The quick of it is that some exercises use oxygen for fuel (are aerobic), while others do not (are anaerobic). While both forms of exercise will benefit your health even more than lube benefits your sex life, understanding the nitty-gritty differences between aerobic and anaerobic exercise will help you figure out the best workout splits for your health and fitness goals.

With that in mind, we put together this in-depth guide on aerobic and anaerobic exercise. Ahead, a detailed look at what each type of conditioning can and cannot do for your health and fitness, as well as tips for incorporating both into your exercise routine.

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Aerobic exercise = traditional cardio

“Aerobic exercise is what most people would think of as a standard cardio workout,” says exercise physiologist and certified strength and conditioning coach Sharon Gam PhD, CSCS.

Inclusive of exercises like jaunts on the elliptical and slow-and-go jogs, aerobic workouts are low to moderate-intensity sweat sessions that get your heart and breath rate up and can be sustained for an extended period, she explains. In fact, “long endurance events like triathlons, marathons, and ultramarathons all count as aerobic exercises, too,” Gam says. A day on the ski slopes, meandering a hiking trail, or paddling a kayak qualify, too.

The term “aerobic” translates to “with oxygen.” With that, during aerobic exercise, you use the oxygen that you breathe to create energy. More specifically, “your body uses oxygen from the air you take in to break down fat stores into fuel,” Gam explains.

The catch is that there are many (many!) steps in the chemical process of turning fat into energy, Gam explains, so it takes a relatively long time. If your workout transitions from low intensity to high intensity—for instance, you start going harder or faster—your energy needs go up. If the aerobic energy system can no longer keep up with your energy demands, your body will start using alternative energy sources as the anaerobic energy system takes over. (The point at which someone switches from aerobic to anaerobic exercise is known as the aerobic threshold).

There are many physical, mental, and emotional benefits of aerobic exercise

Given that we live in a go-go-go world of fast-fashion, hustle culture, and social media quick hits, you’d be forgiven for assuming that exercising as hard or as fast as you can (aka exercising anaerobically) is always best—but actually, that is not the case.

As Gam explains, there’s no hierarchy between anaerobic and anaerobic exercise wherein one comes out on top. Rather, both have unique health and fitness benefits that can facilitate a life of well-being, freedom, and independence with age.

1. It improves overall health

From an overall health standpoint, aerobic exercise is no joke. “Aerobic exercise has been shown¹ to help manage or prevent dozens of chronic diseases,” Gam says, including lower respiratory diseases, obesity, cancer, cardiovascular disease, diabetes, and stroke.

2. It supports your heart health

“Your heart is a muscle, and as it pumps more oxygenated blood through during [aerobic] exercise, it becomes stronger,” explains Mironda Meyers, CPT, a level 2 CrossFit coach and certified personal trainer. On the day-to-day front, “this results in you being less winded doing simple tasks because your heart is strong enough to handle it,” she says.

And in the bigger picture, this means aerobic exercise can help manage or prevent cardiovascular disease, Gam says. “It makes your blood vessels more flexible and responsive, all of which can lower blood pressure and support cardiovascular health,” she explains.

3. It can boost your mood

“Aerobic exercise can build physical and mental resilience to stress, decrease symptoms of depression and anxiety, improve memory, focus, and creativity, increase immune system function, and improve sleep,” Gam says. How? This kind of exercise results in a whoosh of feel-good brain chemicals that boost your mood, she explains. In other words, a runner’s high isn’t just an aspirational state, but a physiological inevitability of aerobic exercise.

4. It increases overall fitness 

Public service announcement for all the folks with a fitness event in the pipeline: “Aerobic exercise increases your fitness capacity and makes you better at endurance exercise,” Gam says.

The mechanisms through which this happens are complex. “Your blood vessels learn to deliver more oxygen and nutrients to your muscles and get rid of waste products more effectively, the number of enzymes in your muscles that help you break down fat into fuel increase, and your mitochondria learn to function better and create energy more efficiently,” Gam explains.

“Aerobic exercise increases your fitness capacity and makes you better at endurance exercise.” —Sharon Gam, PhD, CSCS

Almost everyone can (and should!) do aerobic exercise

Aerobic exercise is like Friday Night Lights re-runs in that it may not be for all, but it is for most. “There isn’t anyone who should totally avoid aerobic exercise,” Gam says. While anyone with an underlying health condition should get the green-light from a provider before adding aerobic exercise—or a new kind of aerobic exercise—into their routine, it’s generally safe for most people, she says.

“Aerobic fitness is a great intro to exercise for beginners, as well as an individual who hasn’t exercised in a long time,” Meyer says. This incredibly accessible type of exercise can be done without any equipment or gym membership, as it’s inclusive of long walks, neighborhood jogs, and freestyle dancing in your underwear.

“Aerobic exercise is also a great option for anyone recovering from an injury, as it’s less strenuous on your body and easier to recover from than anaerobic exercise,” Gam says. Though, it should go without saying that anyone with an injury should chat with their physical therapist or healthcare provider before starting a new exercise routine.

Anaerobic exercise = Short sprints

“Anaerobic exercises are short, high-intensity activities,” Gam says. A broader range of exercisers than you might expand, anaerobic exercise includes the like of the 100-meter dash, 50-yard front crawl sprint, heavy five rep back squat, one-rep max snatch or clean and jerk, and plyometric box jumps. The exact opposite of endurance work, anaerobic work is work that your body can only sustain for a minute or two at a time, she says.

Want to understand why the body cannot do anaerobic exercise for longer than that? Let’s start by looking at the definition: Anaerobic means without oxygen, Meyer says. This type of exercise requires energy in a volume and at a speed that your body is physically unable to provide by turning fat into fuel (with oxygen), she explains. As a result, the body has to create energy without using oxygen either by breaking down glycogen (a form of glucose) that has been stored in the muscle, she says.

“Energy can be made more quickly this way, which is why anaerobic exercise can be done at a higher intensity,” Gam explains. However, eventually, all those glucose and glycogen stores become depleted, she says. At this point, you stop being able to sustain your initial intensity, and your power output or speed dip.

The two energy systems are constantly in conversations, so when your anaerobic system taps out, your aerobic system takes over. Ultimately, this will allow you to keep moving just a lower-intensity or slower pace.

Anaerobic exercise supports overall health and strength gains in a time efficient way

“Anaerobic exercise has many of the same health benefits as aerobic exercise, such as preventing disease and supporting mental health,” Gam says. “But there are also some specific physiological adaptations you can get from anaerobic exercise but not aerobic exercise,” she says. More on these ahead.

1. It builds muscle strength

If your anaerobic training includes strength training, you experience increased muscle mass and strength, Gam says. As you might guess, this is important for anyone who competes in a strength-related sport like Olympic lifting, CrossFit, or powerlifting. But, boosted strength benefits people of all ages and goals, according to Meyer. “The stronger you are, the easier it is to do simple things around the house, help a friend move, carry the groceries, or lift up your child or grandchild with ease,” she says.

2. It boosts power and speed

Hate to break it to you, but “you can’t get faster until you train your speed,” Meyer says. Nor can you get more powerful until you train power output. Anaerobic workouts such as sprinting, plyometric exercises like jumping, and interval training where you alternate between bursts of high intensity and rest will work your anaerobic system, she says.

As an added bonus, the anaerobic exercises that support power and speed help train a type of muscle-fiber called short-twitch muscle fiber, explains certified personal trainer and registered dietitian Maelee Wells Sutton, MS, RDN, ACSM-CPT with Crunch Fitness. “Training anaerobically increases the efficiency of these muscle-fibers, thus helping you become more powerful,” she says.

3. It increases your lactate threshold

If you’ve ever done a challenging workout, you’re probably familiar with the hurt-so-good burning sensation that follows. The culprit behind that fiery feeling is lactic acid. Gam explains: When converting glycogen into energy while exercising anaerobically, waste gets created. Fatigue starts to set in when this waste (lactic acid and hydrogen ions) builds up faster than you can remove them, she explains.

Thing is, if your body gets more efficient at removing that waste, then you can exercise for longer before fatiguing out. And that’s where anaerobic exercise comes into play. The more anaerobic exercise you do, the better your lactic threshold will become, Gam says.

Essentially, this means that you’ll be able to do more anaerobic or aerobic exercise before leaden legs and generalized soreness sets in. “This mostly matters to athletes, but for another person trying to improve their health or their endurance performance, it can also be helpful,” Gam says.

4. It’s time efficient

“Anaerobic exercise may have many of the same health benefits as aerobic exercise, but it can often get you those benefits more efficiently than aerobic exercise,” Gam says. “Anaerobic exercise provides a greater stimulus for both physical and mental fitness improvements than aerobic exercise, since higher intensity exercise is more challenging for your body and mind,” she explains. In action, this means you can get similar benefits in less time.

Anaerobic exercise can benefit almost everyone but it has to be customized

There is a widespread misconception that anaerobic exercise is only for young, healthy folks. But “even though anaerobic exercise is high intensity, it’s still safe for most people— including people with chronic health conditions,” Gam says. A 2016 study² published in the Journal of Sport and Health Science reported that high-intensity exercise was safe, as well as more effective for heart failure patients.

Of course, “if you do have a health condition, injury, or haven’t exercised before or in a while, it’s important to consult your doctor to make sure you’re cleared for exercise,” Gam says. Your physician will help you figure out exactly what types of anaerobic exercise best meets your overall health and fitness needs, as well as what dosage, Meyer says.

“Someone with a pre-existing knee injury, for example, might not be allowed to do any rebounding or jumping but they probably can do kettlebell swings, battle ropes, or any activity they can do that doesn’t cause pain,” Meyer says. Meanwhile, someone else might not be able to do HIIT, but can safely strength train, Sutton says.

“Anaerobic exercise may have many of the same health benefits as aerobic exercise, but it can often get you those benefits more efficiently than aerobic exercise.” —Sharon Gam, PhD, CSCS

Here’s how to add aerobic and anaerobic exercise into your workout routine

The quick-and-dirty is that everyone should incorporate some aerobic and some anaerobic exercise into their exercise lineup each week. “Exactly how is going to be heavily dictated by an individual’s goals, access to equipment, and current health and fitness,” Sutton says.

For optimal health, the American College of Sports Medicine (ACSM) currently recommends all adults aged 18 to 65 get a minimum of 30 minutes of aerobic activity five days per week, and strength train (read: exercise anaerobically) a minimum of two times per week.

The key word in these recommendations is minimum, as people with specific health or fitness goals may choose to ramp up the presence of aerobic or anaerobic work they do each week, Sutton says. For instance, someone who wants to maximize strength and muscular gains will want to prioritize anaerobic training, and limit aerobic exercise to three days or less per week, she says.

“This will allow an individual maximize performance in the strength-focused portion of the workout routine, which maximizes strength gains,” Sutton says. Meanwhile, someone who wants to PR their half marathon or marathon might do four long runs a week, plus a strength training session and sprint (anaerobic) workout session, Gam says.

Aerobic vs. anaerobic exercise: Which is right for you?

If you remember one thing from this article let it be this: Everyone should find a way to safely incorporate both aerobic and anaerobic exercise into their routine. How you choose to balance aerobic and anaerobic exercise, however, will depend on factors like your current fitness level, health status, age, current goals, and more, Gam says.

If you’re new to exercise, Gam says it’s best to start with the ACSM’s recommendations—ideally working with a certified trainer who can teach you how to lift safely. Over time you can increase the amount of anaerobic exercise you hit each week, if your goals call for it.

“Advanced exercisers might up their anaerobic exercise quantity up to three per week, and fill their non-rest days with aerobic work,” Gam says. But ultimately, the best way to find an aerobic versus anaerobic breakdown that is right for you is to hire a fitness professional.