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Aerobic vs anaerobic: What's the difference?

Aerobic versus anaerobic: What's the difference top image

When it comes to exercise, you may have heard the terms aerobic and anaerobic thrown around, but what do they mean and why are they important? Let's explore the key differences between these two types of exercise.

Aerobic exercise

Aerobic exercise refers to activities that get your heart pumping and increase your breathing rate.

Your aerobic energy system relies on oxygen to produce energy. It predominantly utilises fats and carbohydrates:

  • Fats: At lower intensities, your body uses stored fats as a fuel source. Body fat (adipose tissue) releases fatty acids into your bloodstream, where they are transported to the active muscles and broken down to produce ATP, which serves as the primary energy currency of cells.

  • Carbohydrates: As the intensity of aerobic exercise increases, your body shifts from fat to carbohydrates as a fuel source. Stored carbohydrates, called glycogen, are broken down into glucose molecules, which are then transported to the active muscles. These are then converted within the glycolytic system to produce ATP.

The beauty of aerobic exercise is that it provides long-lasting energy through the efficient use of oxygen. This means you can perform low-to-moderate intensity exercise for extended periods without feeling exhausted.

Aerobic fitness

Anaerobic exercise

Anaerobic exercise is all about high-intensity activities, such as sprinting or heavy weightlifting, that go beyond your body's ability to supply sufficient oxygen.

During anaerobic exercise, your body relies on 2 energy systems, the phosphagen system and the glycolytic system:

  • The phosphagen system: Provides immediate energy without the need for oxygen by utilising stored ATP and stored phosphocreatine in the active muscles. This process is rapid but limited in supply, it only provides energy for around 10 seconds.

  • The glycolytic system: As phosphocreatine stores quickly deplete, the glycolytic system (using stored carbohydrates) takes over. While this process is similar for both aerobic and anaerobic exercise, anaerobic exercise leads to the build-up of lactic acid, which can cause muscle cramps.

Anaerobic fitness

In summary

Aerobic exercise relies on oxygen for sustained energy, while anaerobic exercise works without oxygen. Aerobic activities are low-to-moderate in intensity and can be sustained for a longer duration, while anaerobic exercise is high in intensity, and focuses on building strength and power.

The primary fuel source utilised by your body depends on the intensity, duration, and type of exercise. Lower-intensity aerobic activities rely more on fats, while higher-intensity aerobic activities and anaerobic activities heavily rely on carbohydrates. Proper nutrition plays a key role in optimising performance and supporting your main energy systems during exercise.

It's important to note that many programs can incorporate both aerobic and anaerobic exercises. Interval training, for example, combines high-intensity bursts with periods of lower-intensity recovery.

If you understand the differences between aerobic and anaerobic exercise, you can tailor your workouts to meet your specific goals. Whether it's losing weight, improving your endurance, or building strength, regularly incorporating both types of exercise can lead to a well-rounded and effective fitness routine.

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