Chances are you’ve heard of anaerobic exercise before, but how much do you know about the science behind this vital aspect of your fitness? Improving your understanding of the anaerobic energy system is a sure way to empower yourself and give your workouts a boost.
Anaerobic exercise is any physical activity performed at high intensity for a short period of time. Actually, that may mean jumping over one of the best exercise bikes (opens in a new tab) for a short sprint, jumping or even Weightlifting (opens in a new tab) – as long as the intensity is high and the duration short, it will put your body into an anaerobic state.
What is anaerobic exercise?
An anaerobic workout involves short bursts of high-paced physical activity punctuated by interval periods of rest or recovery exercises. Sprints, push-ups, pull-ups, burpees, jumping jacks, and lunges are great examples of anaerobic exercises, as they involve short bursts of energy-consuming movement.
Timing is key: sustain the exercise for the right amount of time and the body will break down glucose to provide energy for the muscles as they work, the primary process for entering and maintaining an anaerobic state. However, if this intensity is maintained for too long, the body will begin to send oxygen to transport glucose to the muscles, which means that it has entered a aerobic (opens in a new tab) condition.
A perfect example of anaerobic exercise is high-intensity interval training (HIIT), according to exercise physiologist Richard Avery. “HIIT is also a popular and effective way to incorporate anaerobic exercise into your training,” he says. “HIIT combines repeated short bursts of intense activity, with rest or lower-intensity recovery periods in between, to help focus the anaerobic energy system.”
Avery is an exercise physiologist and an exercise and applied sport scientist at the University of East London. He has a master’s degree in exercise physiology and currently divides his time between teaching, consulting work, and research.
What happens to your body during anaerobic exercise?
When you perform anaerobic exercise, the body breaks down glucose, which essentially acts as a fuel from which adenosine triphosphate (ATP) molecules are formed.
“ATP molecules store energy inside our cells,” Avery says, “that can be quickly released for muscle activity to occur. Once ATP is used for energy, it must be re-synthesized, but during anaerobic exercise, ATP cannot be replenished as quickly as it is used. This is why high-intensity activities can only be sustained for periods of up to three minutes.”
Once your body has depleted its ATP stores, it begins to use oxygen to transport energy to your muscles. At that time, he enters an aerobic state. This is why interval periods in anaerobic training are vital: they allow the body to restore ATP within the cells.
Using HIIT as an example, Avery says, “HIIT uses periods of lower intensity to recover between anaerobic efforts. During recovery periods in HIIT sessions, you will notice a higher than usual breathing rate and heart rate as the body has a higher demand for oxygen to restore ATP within the cells.” The need for this recovery period is the core philosophy behind circuit training, the enduringly popular style of exercising where you alternate between different body parts. As Avery says, “Circuit training switches to different muscle groups, to allow individual muscles time to replenish ATP stores.”
What is the difference between anaerobic and aerobic exercise?
The big question concerns the difference in results when comparing anaerobic versus aerobic workouts. Why is it important to train the body in a way that prevents the body’s oxygen system from supplying the muscles?
It’s important to note that while no state can necessarily be considered superior in promoting physical benefits, at least according to an article published in the World Journal of Cardiology (opens in a new tab) – It is proven that aerobic exercise strengthens the heart and respiratory system. Anaerobic exercise is helpful in improving your endurance as well as developing the efficiency with which your body uses oxygen. It also strengthens muscles and bones and optimizes the way muscles deal with lactic acid buildup.
Anaerobic exercise has also been linked to better moods after exercise, with a review published in The Journal of Psychology (opens in a new tab) suggesting that the latter offers greater benefits to combat stress and anxiety. Remember, though, that the key is short, high-intensity bursts to ensure the body is using the correct energy system.
“At any given time, all three energy systems are active, but the contribution of each system is highly dependent on exercise intensity,” says Avery. “The phosphagen system has the fastest rate of ATP production, but it can only sustain itself for about 10-30 seconds. During high-intensity exercise, the glycolytic system is the main anaerobic energy pathway from 30 seconds to two minutes of activity. Beyond that, your body will deplete its ATP stores and you won’t feel the benefits of an anaerobic state.
Is anaerobic exercise important for your physical condition?
Yes, anaerobic exercise is definitely important for fitness. “The American College of Sports Medicine and the NHS recommend that all adults, ages 18 to 65, do muscle-strengthening activities at least twice a week,” says Avery.
For those entering middle age, anaerobic routines are especially important because they may help maintain muscle and Bone density (opens in a new tab)two areas that experience a gradual and natural deterioration with the arrival of age.
However, if you want to increase bone density (opens in a new tab)Avery adds that this training “should be specific and progressive to stimulate increases in bone mineral density or, sometimes, in cases of osteoporosis, to reduce the rate of bone mineral density loss.” To give an example, weight training is a proven way to build bone strength.
Even long-distance runners and cyclists can feel the benefits of anaerobic exercises. While primarily aerobic workouts, these activities incorporate elements of the anaerobic energy systems. “As a runner, I incorporate both aerobic and anaerobic exercise into my training,” says Avery, “which is beneficial for the quick early start of a race and vital for the all-important sprint finish.”
Now that you know the benefits of an anaerobic exercise routine, check out the the best time to exercise (opens in a new tab) for optimal training and make sure your own weekly workouts incorporate some degree of high-intensity interval-based training. The more you do, the more you earn and the benefits are undeniable.
