You've probably heard of aerobic exercise before, but how well-versed are you in the science that underpins this essential component of physical fitness? Giving your workouts a boost and enhancing your understanding of the anaerobic energy system are two surefire ways to feel more empowered.

Any physical activity that is done for a brief period at a high intensity is considered anaerobic exercise. In actuality, that can entail sprinting quickly on one of the greatest exercise bikes, skipping, or even weightlifting. As long as the intensity is high and the time is brief, you'll put your body into an anaerobic state.


An anaerobic workout consists of brief bursts of intense physical activity separated by rest or recovery exercises. Among the most common anaerobic activities include sprinting, pushups, pullups, burpees, jumping, and throwing since they all involve short bursts of energy-draining motion.

Timing is everything: if you exercise for the correct amount of time, your body will start metabolizing glucose to give your muscles energy as they work. This is the major step for achieving and maintaining anaerobic conditions. The body will start to send oxygen to transfer the glucose to the muscles if this intensity is sustained for an extended period, which indicates that the person has switched to an aerobic(opens in new tab) state.

High-intensity interval training (HIIT), in the opinion of exercise physiologist Richard Avery, is a prime example of anaerobic exercise. He adds that HIIT is a well-liked and practical method of including anaerobic activity in training. "

What Happens To Your Body During Anaerobic Exercise:

Anaerobic activity causes the body to break down glucose, which essentially serves as a fuel for the production of adenosine triphosphate (ATP) molecules.

According to Avery, "ATP molecules store energy within our cells, which can be swiftly released for muscle movement to occur. To refill ATP after it has been used for energy, it must be manufactured. However, during anaerobic exercise, ATP cannot be replenished as quickly as it is being utilized. Because of this, high-intensity activities can only be maintained for up to three minutes at a time.

When your body runs out of ATP, it starts to use oxygen to move energy to the muscles. At that point, it starts to breathe more easily.


Avery provides HIIT as an illustration, stating that it includes recovery intervals of reduced intensity in between anaerobic attempts. Because the body needs more oxygen to rebuild ATP within the cells, you will notice higher breathing frequency and pulse rate during recovery intervals in HIIT exercises. The fundamental idea behind circuit training, a perennially well-liked kind of exercise where you alternate between different body regions, is the necessity of this recovery interval. Circuit training switches to various muscle groups, as Avery puts it, "to give individual muscles time to rebuild ATP stores."

What's the difference between anaerobic and aerobic exercise?

The main concern relates to the differences in results between aerobic and anaerobic exercise. Why is it vital to exercise the body so that the muscles cannot receive oxygen from the body's circulatory system?

While neither state is inherently better than the other for generating physical benefits, aerobic exercise has been shown to improve the heart and the respiratory system, at least according to one article published in the World Journal of Cardiology(opens in new tab). Anaerobic exercise is beneficial for increasing your body's ability to use oxygen efficiently and for enhancing your endurance. Additionally, it fortifies bones and muscles and improves how well your muscles handle lactic acid buildup.

A review article in The Journal of Psychology(opens in new tab) suggests that anaerobic exercise delivers better benefits in reducing stress and anxiety than aerobic exercise does for mood improvement post-exercise. To guarantee that the body is using the right energy system, keep in mind that short bursts of high intensity are the key.

The contribution from each of the three energy systems varies greatly depending on the level of exercise, according to Avery. The phosphagen system produces ATP at the fastest rate, but it can only be maintained for 10 to 30 seconds. From 30 seconds to two minutes of high-intensity exercise, the glycolytic system serves as the primary anaerobic energy pathway.

Is anaerobic exercise important for your fitness?

Anaerobic activity is unquestionably crucial for fitness. All adults between the ages of 18 and 65 are advised to engage in muscle-strengthening activities at least twice per week, according to the American College of Sports Medicine and the NHS, adds Avery.

Anaerobic exercises are particularly crucial for people who are approaching middle age since they may help preserve muscle and bone density, two things that naturally deteriorate as we age.

Avery adds that this training "has to be precise and gradual to encourage gains in bone mineral density, or occasionally in cases of osteoporosis, to limit the pace of bone mineral density loss" if you want to raise bone density(opens in new tab). As an illustration, weight training is a known method for enhancing bone strength.

Anaerobic exercise has advantages that can be felt even by long-distance runners and bikers. Although they are predominantly aerobic exercises, these activities also involve anaerobic energy systems. Running requires both aerobic and anaerobic exercise, which is helpful for the first quick start of a race and essential for that crucial sprint finish, according to Avery.

Now that you are aware of the advantages of an aerobic exercise program, check out the ideal training period(opens in new tab) and make sure that your personal weekly exercises include some form of interval-based, high-intensity training. The rewards are undeniable, and the more you put forth, the more you'll earn.