26/11/2025
Aerobic vs. Anaerobic Exercise – How Your Body Uses Energy and How to Train Smarter
When we exercise, our muscles need energy. The way our body produces that energy depends mainly on how hard and how long we are working. In sport physiology, this is explained through two key systems: aerobic and anaerobic exercise. Understanding the difference can help you train safely and more effectively.
🏃♂️ Aerobic Exercise
Aerobic literally means “with oxygen.” During activities like brisk walking, jogging, cycling or swimming, your heart and lungs can supply enough oxygen to the muscles to keep you going comfortably for longer periods. Your breathing is deeper, but still controlled, and you can often talk in full sentences.
Aerobic training is the foundation of good cardiovascular health. It helps lower blood pressure, improve cholesterol, reduce inflammation, and increase your overall endurance. It is also excellent for weight control and reducing long-term risks of heart attack and stroke.
🏋️♀️ Anaerobic Exercise
Anaerobic means “without oxygen.” These are short, intense efforts—like sprinting, HIIT intervals, or heavy strength training—where your body needs energy faster than oxygen can be delivered. In these moments, your muscles switch to a quicker energy system that relies on stored sugars and produces lactate, which creates the familiar “burning” feeling.
Although these bursts are short, anaerobic exercise plays a crucial role in building strength, power, speed and muscle mass. It also helps with glucose regulation and bone health. Because it places more stress on the body, it should be added gradually, especially for beginners.
❤️ A Simple Heart Rate Guide to aerobic and anaerobic training
A helpful way to understand whether you are training aerobically or anaerobically is to look at your heart rate.
First, estimate your maximum heart rate (MHR) using the formula:
220 minus your age
Most of your training should take place in the aerobic zone, which is roughly 60–75% of your MHR. At this intensity you can still speak, your breathing is steady, and your body relies more on oxygen and fat as fuel. For a 40-year-old, this means staying between roughly 108 and 135 beats per minute.
The anaerobic zone begins at around 80–90% of your MHR. Here, talking becomes difficult, your breathing is rapid, and your muscles rely more on stored sugars. For the same 40-year-old, this would be roughly 144 to 162 beats per minute. Short intervals in this zone can boost performance, but they should be used carefully and ideally after a proper warm-up.
🤔 How Much of Each Do You Need?
For most people aiming for general health, the majority of weekly exercise should be aerobic (80–90% of total weekly training). Anaerobic work can be added in small amounts once a good fitness base is established (10–20% of total weekly training). Athletes adjust this depending on their sport, but for everyday health, aerobic training remains the cornerstone.
📚 References
American Heart Association
https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults
Mayo Clinic – Exercise intensity overview
https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/exercise-intensity/art-20046887
❗Important: The content of this post is intended as general information, not as medical advice. For any health-related concerns, always consult your own doctor.
