Aerobic and anaerobic exercise explained

There are two systems our bodies use when engaging in any form of exercise: the aerobic and anaerobic system. The former relies on oxygen as fuel, the latter does not.  

Aerobic exercise 

  • is any low to moderate intensity workout where simply “breathing” is enough to finish the workout. I’m not saying anaerobic exercise is where you do not breathe. Instead, aerobic activities are those that can be performed without you gasping for air to save your life. Example: walking, jogging, cycling, running & swimming. 

Anaerobic exercise

  • on the other hand, is any high-intensity activity that is performed with close to maximum effort, typically in short bursts. This is usually when you transform to Super Saiyan 3. Example: sprinting, hill climbing, weight lifting & other contact sports like boxing or Muay Thai.

2 Muscle Types explained

  • Type I or slow-twitch are the first muscle fibers to be activated when engaged in an exercise. They have a highly oxidative capacity (its main source of fuel is oxygen), contract slowly and are predominantly used in low-moderate intensity exercise or endurance training. 

The more you do aerobic exercise, the more you train your slow-twitch muscles and the more you increase your stamina for endurance sports.

  • Type II or fast-twitch are the muscle fibers stimulated under the most intense conditions. They are mainly glycolytic (oxygen isn’t enough as fuel), hypertrophic in nature (leads to increase in muscle size), used for sudden bursts of energy and they easily fatigue (due to the build-up of lactate in the blood).

The more you do anaerobic exercise, the more you train your fast-twitch muscles and the more you put your muscles in hypertrophy. 



Simply put: in an aerobic exercise, the main muscles used are the slow-twitch fibers. In an anaerobic exercise, the fast-twitch.

Now you know why the biggest bro on your gym couldn’t finish a 21-km run if his life depended on it. And why entering a power-lifting competition does not bode well for the marathoner.

This is just to illustrate the “general” difference in the physique of a marathoner and a sprinter. This does not, in any way reflect 100% representation of the same.


Which exercise is best for weight loss?

The aerobic system can be utilized for a much longer period of time compared to the anaerobic system. However, you burn more calories in an anaerobic exercise due to its intensity. The harder the workout, the more effort is needed, thus, more energy expenditure. 

In addition to the calories burned, the body’s metabolism increases even after the anaerobic workout. This is the body’s response to quickly return to its homeostasis (normal metabolic function). 

So after an anaerobic exercise, the body continues to burn calories at a faster rate. Yes, even when you hit the sack after a grueling workout you still burn calories. The opposite is true for aerobic training.

Read more on how to utilize metabolism for weight loss.


Who can do anaerobic exercises?

Anyone with both arms and legs can do the exercise. However, due to the intensity of an anaerobic workout, only the above-average fit folks are the ones who usually reap its benefits. The average joe may find a difficult time in finishing an intense workout. He may end up hating life (me every time I finish a workout). That doesn’t mean we cannot reach our fitness goals now, does it?

One other major drawback…

You can’t do high-intensity exercises every day. You must allow your body to recuperate fully before repeating it. This also means having enough sleep. So let’s say you did High-Intensity Interval Training (HIIT) today; you need to have at least 8 hours of sleep (for the young adults) PLUS a full day of no activity the day after. (If you must, choose a very low-intensity workout.) Otherwise, your body will be at its weakest until it gets its much-needed recovery.

With hard work and perseverance, one can achieve his fitness goals. With anaerobic training, it puts you ahead by leaps and bounds. So if you ask me what the best exercise is for weight loss, my straight up answer is anaerobic exercise.

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