There’s much debate about what type of exercise is better for your health: aerobic or anaerobic.

Aerobic exercise, like walking, bike riding, or running, means you’re moving your body, breathing faster, and increasing your blood flow. It’s a level of activity that you can maintain for an extended period of time.

Can you pass the “talk test?” If you can somewhat comfortably hold a conversation during exercise, not talking as though you are not exercising at all but able to talk while slightly breathless, you’re at an aerobic level.

Anaerobic exercise, like sprinting or weightlifting, is short, intense activity that has you working to the max, and it can’t be sustained for long.

Which is better for weight loss? Both aerobic and anaerobic exercise has benefits, and you should incorporate each into your routine. But, if your primary concern is shedding fat, anaerobic exercise is the way to go.

The science behind aerobic vs. anaerobic

The difference between aerobic and anaerobic exercise comes down to oxygen levels.

In aerobic, or “with oxygen” exercise, your muscles have enough oxygen to produce the energy needed to perform. Anaerobic “without oxygen” exercise means oxygen demand is greater than oxygen supply and you can’t keep up with the energy your body is demanding. This leads to lactate production and eventually the cessation of exercise.

Why anaerobic exercise is better for fat loss

Aerobic exercise, or steady-state cardio, is performed at a steady, low to moderate pace. This type of exercise, which utilizes slow-twitch muscle fibers, is great for cardiovascular conditioning and improving muscular endurance.

While it’s commonly thought that this low-intensity cardio is optimal for fat loss, think again. While it does use a higher percentage of fat for energy as opposed to muscle glycogen, the total amount of energy burned at this level is lower than during anaerobic exercise for a given period of time. This means that for most people, extended periods of aerobic exercise are needed to achieve significant fat loss. This often results in a plateau.

Anaerobic exercise is performed in the form of high-intensity interval training (HIIT), where you rotate high-intensity intervals with recovery intervals. This is beneficial for several reasons.

Save time

First, you can get in an intense workout in a fraction of the time. If time is a limitation for you, a HIIT session is a great option. You’ll exhaust your muscles and burn more calories than you would in the same amount of time doing steady-state cardio.

Burn more calories

Second, you’ll burn more calories in that amount of time. At the end of the day, the harder your workout is, the more calories you’ll burn. HIIT will cause your caloric expenditure to be higher than if you just walked or casually rode your bike for the same period of time.

Increase metabolism

Third, you’ll build muscle and increase your metabolism. HIIT requires your fast-twitch muscle fibers to engage in exercises like sprinting, plyometrics, and weightlifting, which increase muscular size and strength. This means you’ll be increasing muscle mass, which will in turn speed up your metabolism as muscle burns more calories that fat.

The afterburn effect

Fourth, you’ll experience the afterburn effect. The afterburn effect’s scientific name is excess post-exercise oxygen consumption (EPOC). EPOC is the amount of oxygen required to return the body to its resting state. HIIT sessions stimulate a higher EPOC because you consume more oxygen during them, which creates a larger deficit to replace post-workout. This means you’ll continue to burn calories even after your HIIT session is over.

Cons of HIIT

Although HIIT as anaerobic exercise is beneficial for fat loss, there are some cons.

The biggest disadvantage is that it’s not for everyone. You’ll need a basic level of fitness before you can engage in HIIT safely and effectively. If you’re new to exercising, it can be too intense for your body, specifically your heart.

If you’re able to perform HIIT, exercises like plyometrics, sprinting, and weightlifting create an increased chance of injury as these explosive movements are fast and require a lot of force.

And lastly, HIIT can be painful during the session, due to the high intensity, or afterward because of soreness.

HIIT workout

If you feel fit enough to try your hand at some intense anaerobic exercise, try these sample HIIT workouts for maximum calorie burn.

Sprints

Sprint all out for 30 seconds, then recover for 1 minute. Repeat for 20 to 30 minutes.

Circuit training

Complete each exercise in the circuit for 30 seconds with a 10-second break after each if needed. Repeat this circuit continuously for 10 minutes:

  • burpees
  • jump squats
  • bicycle crunch
  • mountain climbers
  • jump lunges
  • pushups
  • jumping jacks

The takeaway

While both aerobic and anaerobic exercise have their place in a well-rounded fitness routine, anaerobic exercise like HIIT can be more effective for fat loss.

If you’re incorporating HIIT and strength training, keep in mind that total weight loss is not an accurate indicator of progress. With exercise like this, your body will undergo recomposition, meaning dropping fat and adding muscle. To track your progress, measure fat loss instead, as muscle is more dense and takes up less space for a given weight.

Check with your doctor before engaging in any high-intensity exercise.