Health and Fitness Knowledge

Fasted Cardio Benefits


Fasted cardio

Fasted cardio is a very popular term among fitness enthusiasts. In simple terms, you perform cardio with empty stomach, usually in the morning . Performing empty stomach fasted cardio training has been touted as one of the best ways to burn body fat everywhere and people are turning to it. You burn around 20 percent more fat.

The preferred energy source of our body are carbohydrates. In fasting cardio, as you is on an empty stomach and will have to resort to other sources of energy, and fat would be the ideal to be consumed.

It is very popular among high-performance sportsmen as it is known for helping to burn fat even performed at low intensities . Since the exercise is not very intense, it is said that the catabolism will also be reduced, and the fat burning happens. For this reason it is so popular in sports.

Thirty minutes in the morning will be enough, but of course, you can increase the time, if you feel that there is a need for you to reduce more fat. The trick is to always keep the intensity low, as this will lessen losses of muscle mass. Now let’s see how  works .

How it works ?

The cardiovascular exercise fasting helps eliminate fat and for many people is the solution to keep the defined abdomen. Doing cardio fasting in the morning is most effective because glycogen stores are low after sleep and body has already used the carbs overnight.

Your body also break down amino acid into glucose overnight. When body consumes all the remaining carbs of the body then it start using the fat. After using all the fats of the body then body start using the muscles mass.  Well its not ideal to do excessive cardio for those who are into body building.

Also, its not that big problem if you consume fast digesting protein like whey, along with the slow digesting casein after your fasted cardio.

Remember that the more different approaches you try, the more chances you find the training methodology that offers you the most benefits.

However, some say that this extremely helps you in burning a lot of fat, while others point out that this can result in muscle loss especially if done in a complete fasting state. Who is right?

HIIT and Fasted Cardio

High-intensity interval training burns more calories and fat after workout as compared  to low-intensity cardio. With high-intensity interval training (HIIT), you burn calories almost for the entire day, even when you are doing nothing for the rest of the day.

The cardio done in the morning can increase the amount of free fatty acids (FFA) that will be used as fuel, although this is not really because we are doing aerobics with emptying glycogen stores. Unless we go to sleep with the glycogen deposits already low, we will not have them at a low level upon awakening. Therefore it is important to understand that fasted cardion is a process .

If you have to see great results you have to eat in a calorie deficit, mix strength training with cardio and sleep well.

During sleep almost 100% of the energy we spend comes from the fatty acids since the activity performed is of a very low intensity and also because the hormone hGH is naturally released 30 minutes after entering the deep phase of sleep (hGH increases the mobilization of fatty acids).

Therefore, glycogen stores are not really affected during the night. It is possible that the body resorts in part to hepatic glycogen deposits, but even this is not a great expense since they contain 200 or 300 kilocalories in the best of cases. Believing that when we get up our muscles are empty of glycogen is therefore a fallacy.

However, since fat is the primary fuel used during sleep, when we get up there are chances that the amount of free fatty acids will be higher. As these fatty acids do not have to be mobilized (they are already released) they become easier to oxidize to be used as fuel and consequently in the morning they are more ready to be used when doing aerobics.

Points to remember while doing fasted cardio

Performing cardio early in the morning on an empty stomach has these great advantages over exercise at any other time of the day:

  • Before eating , in the early morning, your muscle and liver glycogen levels (stored carbohydrates) are low . If you have dinner at 10 pm and have breakfast at 7 am, your body spends 9 hours without taking any food. So if you are a beginner do not start with intense training. Start with light and then continue accordingly.
  • During this overnight fast of 6-9 hours , glycogen levels gradually provide your body with the glucose needed for various body functions that take place, even while you sleep.
  • As a result , you wake up in the morning with depleted glycogen and reduced blood sugar levels. This is the optimal time of day to burn fat instead of carbohydrates.
  • Because the sessions held in the morning hours, once you finish with it, you will completely forget about the rest of the day of the exercise. Morning exercise will make you feel enthusiastic and fresh the entire day.
  • Getting physical in the morning helps to wake up, increases mental acuity and concentration during the day due to the released endorphins.
  • After fasting the glycogen stores are low and the body is forced to burn fat during the run. This effect is even greater during a low carbohydrate diet or intermittent fasting .
  • With low levels of insulin the body is in the mode of burning fat. Carbohydrates in breakfast foods causes increased insulin, interfering with the mobilization of fat as an energy source. The less insulin is present during fasting cardio, the more fat will be used as an energy source.
  • Fasting cardiovascular exercise helps increase insulin sensitivity, which eliminates fat without affecting hormone balance. High insulin sensitivity has many health benefits, especially for people with a family history of diabetes.
  • The metabolism is accelerated for several hours after exercise.
  • Healthy diet should be maintained. Processed food, grains and sugar should be avoided. Eat lots and lots of veggies and add protein in diet.
  • Implementing high intensity training will give the best results in the shortest time period.

Tips & Conclusion

Yes, fasted cardio is an exercise to be include in a weight/fat loss routine. It is a controversial issue, but if performed with whey protein or slow digesting casein the losses of muscle mass will be minimized.

However in my opinion you do not need to worry about loosing muscle mass as it is the last energy resource the body uses when you are performing fasted cardio. It only happens when your cardio time is say more than an hour. So performing a light cardio for 30 minutes will do wonders for those who are trying to loose that viseral layer of fat which are hiding your abs .

So do give this a shot and try to be consistent for at least a month to see good results .



I am Shweta Singh, Director and CEO of Kirola Sports Private Limited. Former national level player in basketball, taekwondo and high jump. I have also started training in Mixed Martial Arts. Health, fitness and motivation are pillar of success for every individual. My only aim is to make every individual fit and healthy. I will be motivated if my blogs motivates you to take one step closer towards your fitness goals. Kirola team will help you to stay fit and healthy through our blogs . We also aim to motivate you all through motivational stories of lesser known people and about their struggles and achievements. If  you need any assistance and guidance related to health and fitness. Contact us.

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