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

A split image with a person lifting weights on the left and running on the right representing anaerobic vs aerobic exercise.

In the general public, there can be confusion over anaerobic vs. aerobic exercise. Often, the discussion surrounds which form of exercise is better for weight loss or overall fitness.

While there are important differences between aerobic and anaerobic exercise, both are important. According to the U.S. Department of Health & Human Services (HHS), adults should perform at least 150-300 minutes of moderate-intensity or 75-150 minutes of vigorous-intensity aerobic physical activity each week. The baseline for anaerobic activity is two days of moderate-intensity exercise each week that involves all major muscle groups. Unfortunately, only 23.5% of U.S. adults meet both physical activity guidelines, according to the Centers for Disease Control and Prevention (CDC).

The following sections take a look at aerobic and anaerobic exercise, along with how they compare with and complement each other.

What is Aerobic Exercise?

According to the American College of Sports Medicine (ACSM), aerobic exercise refers to rhythmic activities that use large muscle groups. The “ACSM’s Guidelines for Exercise Testing and Prescription” noted how aerobic exercise can span several types of activity:

  • Endurance activities requiring minimal skill or physical fitness to perform, like walking, cycling, and water aerobics.
  • Vigorous intensity endurance activities requiring minimal skill, like jogging, running, spinning, elliptical exercise, and fast dancing.
  • Endurance activities requiring skill to perform, like swimming, cross-country skiing, and skating.
  • Recreational sports like basketball, soccer, hiking, and racquet sports.

“Aerobic” means “with oxygen,” and that defines what occurs in the body during this type of exercise. When people engage in aerobic exercise, the heart pumps oxygenated blood to working muscles so they can burn fuel and move. Note that the body may only burn carbohydrates and fats in the presence of oxygen.

Aerobic exercise is often referred to as “cardio,” which is a fitting term for its biggest benefit. As an article in World Journal of Cardiology reported, multiple studies have proven the advantages of aerobic exercise in cardiovascular health, and in particular, reversing and preventing heart disease. That’s the leading cause of death in the United States as of 2016, according to the CDC.

The benefits extend beyond cardiovascular health. Studies have demonstrated how aerobic exercise can reduce the incidents of cancer, diabetes, osteoporosis, obesity, and other health conditions, according to an article published in Health Psychology Research. It can also promote people’s mental condition; for instance, research found that aerobic exercise can reduce anxiety and depression.

What is Anaerobic Exercise?

The ACSM characterizes anaerobic exercise as short, intense physical activity that is fueled by energy sources within the contracting muscles. Those types of activities include weightlifting, sprinting, and high-intensity interval training (HIIT).

“Anaerobic” means “without oxygen.” Instead of receiving energy through oxygenated blood in aerobic exercise, anaerobic exercise requires the body to break down carbohydrates from blood glucose or glucose stored in muscle. Because the body doesn’t rely on oxygen in anaerobic exercise, people can only exercise in this capacity for a short amount of time.

The focus on muscle processes in this type of exercise leads to anaerobic exercise’s primary benefit: building muscle. According to a look at the biochemistry of exercise in the book “Nutrition in Sport,” heavy resistance training for months causes hypertrophy of the muscle fibers, which increases total muscle mass and maximum power output. That’s possible through stretch, contraction, and damage of those fibers.

Other benefits exist for anaerobic exercise. Resistance exercise is a promising modality for maintaining or increasing bone mass and density, according to a review in Endocrinology and Metabolism. Like aerobic exercise, anaerobic exercise can benefit cardiovascular and psychological health, according to World Journal of Cardiology and Health Psychology Research. The latter noted that in the general population, a single bout of exercise, whether aerobic or anaerobic, can enhance mood and self-esteem.

Aerobic vs. Anaerobic Training: Differences and Similarities

When observing anaerobic vs. aerobic exercise, energy in anaerobic training comes from muscles. In aerobic training, it comes from oxygen and energy stored in carbs, proteins, and fats.

The two types of exercise also have differences when it comes to benefits. Anaerobic exercise is well-known for building muscle, and aerobic exercise is even more recognized for shedding fat. A study in the Journal of Applied Physiology verified those sentiments, and mentioned that aerobics are optimal for reducing fat mass and body mass over resistance training. However, it noted that resistance training is important for increasing lean mass.

In the wider conversation, however, anaerobic vs. aerobic exercise shouldn’t be a concern. Most of the general population will benefit from both types of exercise, and that’s why organizations like the HHS have published guidelines covering anaerobic and aerobic exercise. In fact, those recommended levels of physical activity are similar to the World Health Organization’s global recommendations published earlier, in 2010. At that time, physical inactivity had just been identified as the fourth leading risk factor for global mortality behind hypertension (high blood pressure), tobacco use, and hyperglycemia (high blood sugar).

The health benefits of exercise — both aerobic and anaerobic exercise — are well-documented and widespread. “Population level cohort studies have shown that people who exercise enjoy a higher quality of life and improved health status compared with those with sedentary behaviors, with subsequent reductions in their risk of adverse outcomes such as admissions to hospital,” according to a literature review in BMJ. “Randomized controlled trials have shown similarly favorable findings in arthritis, cancer, diabetes, heart disease, and respiratory illnesses, among other chronic conditions.”

You can help people improve their health and achieve their fitness or athletic performance goals with Aurora University Online’s MS in Exercise Science. The program features hands-on application and provides a strong foundation in exercise physiology, sports nutrition, and sports psychology. Aurora University’s program offers two specializations in sports performance and clinical exercise, and through additional coursework and an internship or capstone experience, you’ll be prepared for either of the following industry-leading certification exams:

  • The American College of Sports Medicine’s (ACSM) Clinical Exercise Physiologist (CEP) exam.
  • The National Strength and Conditioning Association’s (NSCA) Certified Strength and Conditioning Specialist (CSCS) exam.

All courses in the degree feature expert instructors with extensive experience in their fields.