Should you do cardio on an empty stomach to burn more fat? It is one of the most debated topics in the fitness world.
Some people believe that empty stomach cardio fastens their fat loss results whereas others say that it can hinder the performance.
So which is the better strategy for fat loss and why? This article will clear all your doubts that whether you should do cardio on an empty stomach or not.
Is Cardio On An Empty Stomach Effective?
A study published in the “British Journal of Nutrition” shows that people when doing cardio on an empty stomach burn 20% more fat than when they took a meal beforehand. Some other studies show the same results.
How Does It work? (Science Stuff)
There are two major fuel sources that your body uses to produce energy for exercise – carbohydrates and fats. From them, the carbs you eat are the primary energy source and stored body fat is secondary.
For endurance exercise or for steady-state cardio done at moderate intensity, you get about half of the energy from glycogen stores in your body and rest from fats.
Now when you do early morning cardio on an empty stomach, your glycogen stores are depleted by fasting overnight. Due to which, your body switches to the secondary energy source which is the stored fat in your body. These stored fatty acids break down in the mitochondria to produce energy.
A study was done on eight healthy men to check the fat burning effects of doing cardio on an empty stomach. Tests were performed on the subjects: once in the feed state and one week later, on an empty stomach.
Results showed that after about 30 minutes of exercise, the fat-burning rate was higher during the empty stomach cardio. This fat-burning effect remains continued for about an hour of exercise.
SUMMARY: Doing cardio on an empty stomach burn more fat as your glycogen levels are depleted. But you get these fat burning benefits during the exercise only.
Does Empty Stomach Cardio Burn More Fat Overall?
Your body can use any of the three macronutrients – protein, carbs, and fat, as fuel sources. It depends on various factors like workout intensity or what and how much you are eating. One will become the primary source to generate fuel but only for a limited time.
If your body burns fat during exercise, as in the case of empty stomach cardio, it will use carbohydrates afterward. On the other hand, if your body is using carbohydrates as the primary source of fuel during a workout, then it will use more fat post-workout. This is called the “after-burn” effect. This occurs because of the increased level of metabolism.
Studies show that people who burn more fat during workouts actually burn less fat for the rest of the day. Remember that, fat burning occurs over the course of a few days. It is not a matter of a few hours.
SUMMARY: You may burn more fat during empty stomach cardio but the overall fat loss remains the same as you burn less fat for the rest of the day.
Downsides Of Doing Empty Stomach Cardio
Here are some possible downsides of doing empty stomach cardio…
Your Overall Fat Loss Will Remain The Same
By doing cardio on an empty stomach, you will lose more fat during the session. But if you look at the big picture the thing remains the same. You will burn less fat for the rest of the day. Therefore, you don’t get any extra fat loss benefits of doing empty stomach cardio.
You Might Lose More Muscle Also
When you do cardio on an empty stomach, your body mobilizes more for fuel. But this is not the whole story.
Your body also breaks amino acids into glucose at night. So along with more fat, doing empty stomach cardio in the morning uses more amino acids for fuel. And this is not a good idea if your primary goal is to build muscle.
However, you can minimize your muscle loss by taking a fast-digesting protein like whey right after finishing your cardio routine. Or, it is much better to do your morning cardio after taking a protein shake.
Your Performance May Decline
Studies show that your overall workout intensity may reduce by doing the workout on an empty stomach. During exercise, you get most of your energy from the glycogen stored in your liver and muscles.
Now as your glycogen stores are depleted because you have not eaten anything for about eight hours, you won’t have enough energy to give your peak performance. In addition, you may feel a lack of coordination, reduced focus, and get fatigued faster.
SUMMARY: There is no extra benefit in fat loss of doing empty stomach cardio. In addition, you might lose your hard-gained muscles too.
Eat Something To Burn
There are several reasons to eat before exercise. First is, doing HIIT or any intense workout on an empty stomach will reduce your performance.
Another thing is the thermogenic effect of food digestion. Studies show that it can improve the oxidation of fat. The process of digestion increases your body temperature which leads to better use of nutrients during exercise. This further increases oxygen consumption during exercise.
A study was done on 12 men who performed early morning cardio under two conditions: one was empty stomach cardio and the other is under a feed state.
Results show that eating increases oxygen consumption. When these men did cardio after having a meal, they burn more calories throughout the day after exercise.
Researchers concluded that “low-to-moderate exercise or cardio is done on an empty stomach does not enhance fat loss. Hence, taking a light meal is better before doing cardio for fat loss.”
On top of that, if your goal is to gain muscle or to maintain them, then it is much more important to eat before doing early morning cardio. It will minimize the chances of muscle loss during a fat loss program.
SUMMARY: Studies show that taking a light meal before doing cardio helps in maintaining muscle mass and burns fat throughout the day.
Cardio On An Empty Stomach – In A Nutshell
Doing early morning cardio on an empty stomach looks like an awesome strategy to lose fat. But studies show that there is no extra benefit of doing that.
You might lose burn more fat during the cardio but your overall fat burn remains the same. The reason being, eating before exercise gives you an after-burn effect due to which you lose more fat after the workout for about 24 hours.
So for most people, it is better to eat something before early morning cardio – a light meal or a protein shake is advisable. It will also help you in maintaining maximum muscle mass.
So this was the detailed article explaining why you should not do early morning cardio on an empty stomach.
I hope you liked it. For any queries regarding fitness, feel free to ask in the comment section. Thank you for reading so far.
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