Aerobic exercise is the type of moderate-intensity physical activity that you can sustain for more than just a few minutes with the objective of improving your cardio-respiratory fitness and your health. “Aerobic” means “in the presence of, or with, oxygen.”
You know you’re doing aerobic exercise when your heart’s thumping and you’re breathing faster than you do at rest but you can sustain the activity for extended periods of time. I recommend the cue “warm and slightly out of breath” to determine if your activity level is aerobic.
Walking, jogging, biking, dancing, and swimming are examples of activities that can be performed aerobically.
Anaerobic, on the other hand, means “the absence of, or without, oxygen.” Anaerobic exercise is performed at an intensity that causes you to get out of breath quickly and can be sustained for only a few moments. Weight lifting and sprinting are examples of anaerobic exercise.
What is the difference between aerobic and anaerobic exercise?
A single activity can include elements of both aerobic and anaerobic exercise. For example, interval training, where you alternate cycles of low-intensity (aerobic) and high-intensity (anaerobic) work during the same workout, has elements of both. So does a game of tennis where you might sprint at one moment (anaerobic) and then move less aggressively for several minutes (aerobic) as you hit ground strokes from the baseline.
Most activities can be performed aerobically or anaerobically. For example, you could walk briskly on the treadmill at 3.5 miles per hour and feel warm and slightly out of breath (aerobic), or you could walk very briskly at 4.5 miles per hour and feel very out of breath (anaerobic). The same is true for biking, swimming, dancing, or virtually any other activity. The intensity of the workout determines whether an activity is aerobic or anaerobic, and all you need to do is pace yourself to elicit the type of training you desire.
Aerobic exercise facts
- Aerobicexercise is sometimes known as “cardio”- exercise that requires pumping of oxygenated blood by the heart to deliver oxygen to working muscles.
- Aerobic exercise stimulates the heart rate andbreathing rate to increase in a way that can be sustained for the exercise session. In contrast, anaerobic (“without oxygen”) exercise is activity that causes you to be quickly out of breath, like sprinting or lifting a heavy weight.
- Examples of aerobic exercises include cardio machines, spinning,running, swimming, walking, hiking, aerobics classes, dancing, cross country skiing, and kickboxing. There are many other types.
- Aerobic exercises can become anaerobic exercises if performed at a level of intensity that is too high.
- Aerobic exercise not only improvesfitness; it also has known benefits for both physical and emotional health.
- Aerobic exercise can help prevent or reduce the chance of developing some cancers,diabetes, depression, cardiovascular disease, and
- An aerobic exercise plan should be simple, practical, and realistic. Specific equipment (such as cardio machines) may be used but is not necessary for successful aerobic exercise.
How aerobically fit can we be?
The average sedentary adult will reach a level of oxygen consumption close to 35 ml/kg/minute during a maximal treadmill test (where you’re asked to walk as hard as you can). Translated, that means the person is consuming 35 milliliters of oxygen for every kilogram of body weight per minute. That’ll get you through the day, but elite athletes can reach values as high as 90 ml/kg/minute! How do they do it? They may have good genes for one, but they also train hard. And when they do, their bodies adapt. The good news is that the bodies of mere mortals like the rest of us adapt to training too. Here’s how.
What are the fitness benefits of aerobic exercise?
How our bodies adapt
Here’s what happens inside your body when you do aerobic exercise regularly:
- Your heart gets stronger and pumps more blood with each beat (largerstroke volume). Elite athletes, as I just mentioned, can have stroke volumes more than twice as high as average individuals. But it’s not just that. Conditioned hearts also have greater diameter and mass (the heart’s a muscle too and gets bigger when you train it), and they pump efficiently enough to allow for greater filling time, which is a good thing because it means that more blood fills the chambers of the heart before they pump so that more blood gets pumped with each beat.
- Greaterstroke volume means the heart doesn’t have to pump as fast to meet the demands of exercise. Fewer beats and more stroke volume mean greater efficiency. Think about a pump emptying water out of a flooded basement. The pump works better and lasts longer if it can pump larger volumes of water with each cycle than if it has to pump faster and strain to get rid of the water. High stroke volume is why athletes’ hearts don’t pump as fast during exercise and why they have such low resting heart rates; sometimes as low as 40 beats per minute, whereas the average is 60-80 beats per minutes.
- Downstream from the heart are your muscles, which get more efficient at consuming oxygen when you do regular aerobic exercise (remember, “consuming” oxygen means that the muscles are taking the oxygen out of the blood). This happens because of an increase in the activity and number of enzymes that transport oxygen out of the bloodstream and into the muscle. Imagine 100 oxygen molecules circulating past a muscle. You’re twice as fit if the muscle can consume all 100 molecules than if it can only consume 50. Another way of saying it is that you’re twice as fit as someone if your VO2max is 60ml/kg/min. and theirs is 30ml/kg/min. In terms of performance in this scenario, you’ll have more endurance because your muscles won’t run out of oxygen as quickly.
- Mitochondria inside the muscle increase in number and activity. Mitochondria are the powerhouses of your cells. They do all the heavy-duty work to keep you moving. They use the oxygen to burn the fat and carbohydrate that makes you go. The good news is that they increase in number and activity, by as much as 50%, in just a matter of days to weeks in response to regular aerobic exercise in adults of all ages.
Aerobic exercise: the health benefits
Fitness — including increased cardiorespiratory fitness and endurance (stamina)
Regular aerobic exercise improves your cardiovascular fitness by increasing your capacity to use oxygen. It does this by increasing your heart’s capacity to send blood (and hence oxygen) to the muscles. This is mainly achieved through an increase in the size of the heart’s pumping chambers (ventricles), which means that your heart doesn’t have to beat as fast to deliver the same amount of blood. This is evident in a slower resting heart rate, and a slower heart rate for the same exercise intensity.
As you get ‘fitter’, particular activities (such as walking or jogging at a specified speed) will become easier.
You’ll also be able to undertake the activity for longer (known as endurance), and/or at a higher intensity (e.g. jogging at a faster speed). The same applies to activities such as cycling or swimming, but it should be noted that fitness tends to be specific. So jogging will provide only limited benefits to your swimming fitness and vice versa. However, a side-benefit you may notice is that you also have increased stamina for the everyday activities of life, not just for exercise.
Other fitness improvements occur in the exercising muscles, and are specific to those muscles being used in the mode of exercise (e.g. walking, running, cycling, or swimming). These include an increased capacity for the muscles to take up and use the additional oxygen being delivered by the heart.
Reduced risk of certain health problems
Regular aerobic exercise has been shown to reduce the risk of heart disease, high blood pressure, type 2 diabetes, colon cancer and breast cancer. It can lower blood pressure and improve your blood cholesterol by reducing the levels of LDL-cholesterol (so-called ‘bad’ cholesterol) and increasing the amount of HDL-cholesterol (so-called ‘good’ cholesterol). It can also reduce anxiety, stress and depression, as well as instilling a general sense of well-being. Regular aerobic exercise has even been shown to have the potential to increase your lifespan.
Low-impact aerobic exercise such as swimming is valuable for improving general health and fitness in people who have arthritis or other conditions that limit their ability to do weight-bearing exercise.
Importantly, whereas fitness tends to be quite specific, many health benefits can be gained from any form of aerobic exercise. Additionally, the health gains can be achieved from relatively moderate amounts of exercise — moving from a lifestyle involving no exercise to one that involves some exercise can lead to substantial improvements in health.
Aerobic exercise burns up energy (calories). Regular sessions of 30 to 60 minutes of low to moderate intensity aerobic exercise (at around 55 to 70 per cent of maximum heart rate) can be an important part of a weight loss or weight management programme that is also mindful of the energy (calories) consumed as food.
However, many of the health benefits associated with aerobic exercise occur independently of weight loss. Evidence from large studies has shown that active, overweight people do not have a greater risk of many diseases than inactive people who are not overweight. From a health perspective, it is of course best to be both active and a healthy weight, but if weight reduction is a problem, it doesn’t mean that the exercise is having no benefit.
Improved bone and muscle health
Your risk of osteoporosis (excessive bone thinning as you age) can be reduced by regular weight-bearing aerobic exercise such as brisk walking.
By stimulating the growth of tiny blood vessels in your muscle tissues, aerobic exercise has also been shown to lessen the pain experienced by people who have fibromyalgia or chronic low back pain, as the oxygen supply to the muscles is improved and waste products are removed more efficiently.
Regular aerobic exercise can have social benefits too, whether you walk with a friend, play tennis with workmates, or form a social cycling team. Exercising with friends can also be the most effective way of ensuring that you do it regularly.
Aerobic exercise precautions
As with any form of exercise, be aware of over-exercising, either by doing aerobic exercise too hard, for too long or too often. This approach can lead to injury, and abandoning of your fitness programme. Remember to build up gradually from your current activity level, and not to progress too rapidly. If you are new to regular aerobic exercise, several weeks of low to moderate intensity aerobic exercise are usually advised before introducing more vigorous aerobic exercise sessions.
If you have existing health problems, are at high risk of cardiovascular disease, or have muscle, bone or joint injuries, check with your doctor before undertaking an aerobic exercise programme. Also, men aged over 40 years and women aged over 50 years who have not exercised regularly in the recent past should check with a doctor before undertaking a programme of vigorous physical activity.