You’ve probably 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 surefire way to empower yourself and give your workouts a boost.
Anaerobic exercise is physical activity performed at high intensity for a short period of time. In reality, that might mean hopping on one of the best exercise bikes. (opens in a new tab) for a short sprint, jump rope or weightlifting (opens in a new tab) – as long as the intensity is high and the duration short, you will place your body in an anaerobic state.
What is anaerobic exercise?
An anaerobic routine involves short bursts of high-paced physical activity punctuated by interval periods of rest or cool-down exercise. Sprints, push-ups, pull-ups, burpees, jumps, and throws are all great examples of anaerobic exercise because they encompass brief bursts of power-intensive movement.
The key is timing: keep exercising for the right duration and the body will break down glucose to provide energy to 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 start sending oxygen to transport glucose to the muscles, which means that it has entered an aerobic phase instead. (opens in a new tab) State.
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 periods of low-intensity rest or recovery in between, to help target the anaerobic energy system.”
Avery is an Exercise Physiologist and Applied Sport and Exercise Scientist at the University of East London. He holds a master’s degree in exercise physiology and currently divides his time between teaching, consulting and research.
What happens to your body during anaerobic exercise?
When engaged in 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 in our cells,” says Avery, “which can be quickly released for muscle activity to take place. Once ATP is used for energy, it must be resynthesized, but during anaerobic exercise, ATP cannot be replenished as quickly as the rate at which it is used, which is why high-intensity activities can only be sustained for periods of up to three minutes .
Once your body has depleted its stores of ATP, it begins to use oxygen to transport energy to the muscles. At this point, it enters an aerobic state. This is why interval periods in anaerobic training are essential: they allow the body to restore ATP in the cells.
Using HIIT as an example, Avery says, “HIIT uses periods of lower intensity to recover between anaerobic efforts. During recovery periods from HIIT sessions, you will notice a higher respiratory rate and heart rate than usual, as the body has an increased demand for oxygen to restore ATP to the cells. The need for this recovery period is central to the philosophy of circuit training, the ever-popular style of training where you alternate between different body parts. As Avery puts it, “Circuit training shifts to different muscle groups, to allow time for individual muscles to recover ATP stores.”
What is the difference between anaerobic and aerobic exercise?
The big question is about the difference in results when you compare anaerobic workouts with 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 is important to note that while neither condition 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) – Aerobic exercise is proven to strengthen the heart and respiratory system. Anaerobic exercise is useful for improving your endurance, as well as developing how efficiently your body uses oxygen. It also strengthens muscles and bones and optimizes the way your muscles deal with lactic acid buildup.
Anaerobic exercise has also been linked to improved mood states, post-exercise, with a review published in The Journal of Psychology (opens in a new tab) suggesting that the latter offers greater benefits in the fight against stress and anxiety. Remember, though, the key is short bursts and high intensity to ensure the body is engaging the right energy system.
“At all times, all three energy systems are active, but the contribution of each system is largely dependent on the intensity of the exercise,” says Avery. “The phosphagen system has the fastest rate of ATP production, but can only be sustained for about 10-30 seconds. During high intensity exercise, the glycolytic system is the primary anaerobic energy pathway 30 seconds to two minutes of activity, beyond which your body will deplete its stores of ATP and you will no longer feel the benefits of an anaerobic state.
Is anaerobic exercise important for your fitness?
Yes, anaerobic exercise is definitely important for fitness. “The American College of Sports Medicine and the NHS both recommend that all adults, ages 18 to 65, perform muscle-strengthening activities at least twice a week,” says Avery.
For those entering their 50s, anaerobic routines are particularly important as they may help maintain muscle and bone density. (opens in a new tab)two areas that see gradual and natural deterioration with the onset of age.
However, if you want to increase bone density (opens in a new tab), Avery adds that this training “must be specific and progressive to stimulate the increase in bone mineral density, or sometimes in cases of osteoporosis, to reduce the rate of loss of bone mineral density”. To give an example, weight training is a proven way to build bone strength.
Even distance runners and cyclists can experience the benefits of anaerobic workouts. Although primarily aerobic routines, these activities incorporate elements of anaerobic energy systems. “As a runner, I incorporate both aerobic and anaerobic exercise into my training,” says Avery, “which is beneficial for getting a race off to a quick start and vital for that all-important sprint finish.”
Now that you know the benefits of an anaerobic exercise routine, find out when is the best time to train (opens in a new tab) for optimal training and make sure your own weekly workouts incorporate some degree of interval-based high-intensity training. The more you do, the more you earn and the benefits are undeniable.