What Is Fasted Cardio, Its Effectiveness & Benefits

If you are a fitness enthusiast, then you must be known to the term “Fasted cardio”. This is in fact extremely popular among high-performance sportsmen, as it is known for helping to burn fat even when performed at low intensities. Let us read below and know more about what fasted cardio is, its effectiveness and benefits.

What is Fasted Cardio?

In simple terms it can be said that you perform cardio with empty stomach, usually in the morning and that is known to be one of the best ways to burn body fat everywhere. With fasted cardio, you burn around 20% more of the fat.

The preferred energy source of the body are carbohydrates. In fasted cardio, as you are on an empty stomach and will have to resort to other energy sources, and fat would be the ideal to be consumed. This exercise is not very intense, and it is said that the catabolism will also be reduced, and there happens the fat burning.

Performing fasted cardio for 30 minutes in the morning will be enough. However, you can increase the time, if you feel there is a need for you to burn more of the body fat.

Effectiveness of Fasted Cardio

Doing exercise on an empty stomach or a “fasting state” is now being seen as an effective way to get rid of more calories from fat than carbohydrates which makes it an effective way to boost the fat-burning effects of exercise.

There are few hypothetical explanations suggesting as to why doing fasted cardio first thing in the morning is more likely to burn fat. As an example, cortisol is one such hormone that facilitates in promoting fat metabolism for energy. According to one theory, because the levels of cortisol are high in the morning, doing fat burning exercises on empty stomach are far more effective. The second theory suggests that during the night the resting metabolism of the body continues to function and some amount carbohydrates is available in the morning as a source of energy. However, the body has to bank on fats as the primary source of fuel to do any physical activity especially before breakfast.

There has been some research that supports both the above mentioned hypothesis. As an example, studies show that cardio or any fasted exercise enhances endurance and allows athletes to burn more fats than normal carbohydrates.

This said, term fasted cardio may an effective measure to burn fats but is not recommended as a long term measure to burn calories.

NOTE. It is important to note that eating snack or a meal too soon before exercise can increase the insulin levels, which helps metabolize and store fat. If insulin is elevated before exercising, the result can be altered with less amounts of Free Fatty Acids available for energy production for energy. So, a low-glycemic snack 30 minutes prior to fasted cardio exercise can provide energy for the workout and reduce the risk of elevating levels of insulin.

Benefits Of Fasted Cardio

Increases Growth Hormones

Fasting is a known method to boost growth hormones if you exercise on an empty stomach it increases the growth hormone more. Our body requires growth hormone to burn fat.

Adding cardio exercises done fasting with both slow and fast paced exercises is found to be beneficial in producing increased growth hormone significantly from the Pituitary gland. Since this combo needs significant energy, the body uses the fat stored in the body to get the required energy.

Burn Fats

Fasted cardio has proven to be extremely effective in burning fat, especially if done in an empty stomach the moment you get up. However, post an exercise routine the body needs essential nutrients to provide enough energy to trigger a recovery process.

The body in most cases uses the food that you have consumed as an energy source but the digestive system becomes vulnerable when exercises are done on an empty stomach.

Improves Functioning of Cardiovascular System

There is another benefit of fasted cardio. It is known to improve cardiovascular system function. According to a few studies, people doing fasted cardio had a significant increase in VO2 Max, and muscle glycogen concentrations in comparison to the energy burnt before doing the cardio exercises.


Fasted cardio is an exercise that must be included in a weight/fat loss routine. However, there is a controversial issue, that if performed with whey protein or slow digesting casein, the losses of muscle mass will be minimized. But this must not be a reason to worry about losing muscle mass, as it is the last energy resource the body uses, while you are performing fasted cardio. It happens only when you perform the cardio for more than 60 minutes.

So, performing fasted cardio for 30 minutes will do wonders. So, why not give it a try and see the results? Make sure you are under the supervision of an expert trainer and also be sure that you are consistent enough in your workout routine, at least for a month.

Also Read:

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:November 28, 2018

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