Having a basic understanding of aerobic and anaerobic exercise is a great starting point if you want to get fit, lose weight or improve your sports performance. Both forms of activity can be incorporated into a workout, regardless of whether they are using the best exercise bikes (opens in new tab)hitting the gym or playing a team sport.
Typically, aerobic exercise is classified as a cardio activity lasting more than two minutes and includes sports such as running and cycling. Anaerobic exercise is usually classified as short, intense movements (think sprinting and jumping.)
However, some researchers have argued that these classifications are unhelpful and reductive. We spoke to Alan Ruddock, lecturer in sport and exercise physiology at Sheffield Hallam University, to find out more.
What is aerobic and anaerobic exercise?
Simply put, aerobic means ‘with oxygen’ and refers to the body producing energy by using air. Anaerobic means ‘without oxygen’ and refers to the body producing energy without the use of air.
When you are doing aerobic exercise, you are relying on oxygen as your main source of energy. During more intense bouts of anaerobic exercise, your body needs to get energy quickly in order to rely on stored glucose.
However, we actually use both energy systems for most forms of exercise – so you can’t classify certain activities as purely aerobic or anaerobic.
“The way we assess aerobic exercise is through a face mask on an athlete running on a treadmill or a bike,” says Ruddock. “We measure their oxygen intake and we can use that information to determine the aerobic contribution to a given task.”
Ruddock explains that during these tests, the team never finds exclusive dominance of aerobic or anaerobic energy contributions – there is only a predominance.
Ruddock is an accredited sport and exercise scientist and a member of the British Association of Sport and Exercise Sciences. Currently laboratory director for the Sport and Physical Activity Research Center in Sheffield (UK), he has provided physiological support to Olympians, Paralympians, World, Commonwealth, European and British Champions in a range of sports and has co-authored over 25 scientific manuscripts . .
To support this, a study published in the Journal of Science and Medicine in Sport (opens in new tab) found that a 100-meter sprint was powered by 21% aerobic energy for men and 25% for women. So, although a sprint is primarily an anaerobic activity, a good portion of the energy during exercise can still come from the aerobic system.
As such, Ruddock says it’s important not to use the terms aerobic and anaerobic exclusively and to understand that all exercise uses both energy systems.
Some sports scientists have even called for the terms aerobic and anaerobic to be replaced due to their misuse.
In an article in Sports Medicine (opens in new tab) Sports scientists Karim Chamari and Johnny Padulo suggest that researchers and practitioners should use the terms explosive effort, high-intensity effort, and intense endurance effort.
What is primarily aerobic or anaerobic exercise?
Whether an exercise is primarily aerobic or anaerobic depends on its intensity and duration. As a general rule, the longer the duration of an exercise, the stronger the aerobic dominance. This is partly due to the fact that the intensity of an exercise will decrease as you perform it for longer.
There are other ways to separate the two types of exercise. Mostly aerobic exercise is something with an intensity of 75% maximum heart rate and is something a person can continue for a long time. Examples include running long distances or playing team sports. Explosive activities such as weight training or sprinting are primarily anaerobic. Meanwhile, high-intensity interval training is in between.
If you’re focusing on predominantly anaerobic activities (explosive, intense movements) make sure you include plenty of recovery periods between sessions.
“If you repeat a predominantly anaerobic exercise—like a 6- to 10-second sprint—by the tenth repetition there’s a reduction in the amount of anaerobic energy and the aerobic system kicks in. If there’s only a short recovery time, it becomes quite aerobic. in the end,” says Ruddock.
This is supported by research in the Journal of Physiology (opens in new tab) which showed that power output derives primarily from the aerobic energy system in the tenth repetition of a six-second sprint when the athletes had a recovery time of only 30 seconds.
What are the benefits of aerobic and anaerobic exercise?
For overall fitness, aerobic and anaerobic are both important for different reasons.
Aerobic exercise is important for cardiovascular health because it keeps the heart and blood vessels healthy and reduces the risk of heart-related diseases. If you want to lose weight or get fitter, then your body will require more heavy aerobic exercise, but this should be backed up with predominantly anaerobic strength training to prevent injury.
In comparison, anaerobic exercise is important for strength, coordination and maintaining muscle mass. The American Heart Association recommends strength training at least twice a week to help protect the body from injury and maintain mobility in older age.
Anaerobic activity will also help with metabolic health which means the body is able to respond to food in a beneficial way reducing the risk of obesity, type 2 diabetes, heart disease and stroke.
This article is not intended to provide medical advice and readers should consult their physician or health care professional before adopting any diet or exercise regimen.