Fasted Weight Training: What to Expect (Benefits and Drawbacks)

Planning to switch to fasted weight training routine?

If yes, you need to ask yourself, how much do you know about this exercise pattern?

Fasting and weight training have become immensely popular of late. People are switching to this workout pattern because they believe they’ll get maximum benefits while fasted weight training. However, you might not be 100 percent right.

Several truths and myths are associated with this exercise style, making people confused. Therefore, in this article, we will discuss fasted weight lighting, how to do it, and the pros and cons associated with this workout pattern. We will also hint at whether you should switch to this style of training or not.

Key Takeaways

  • Fasted weight training is a style of training in which exercises are performed on an empty stomach. In this routine, the individuals fast for at least five to six hours before hitting the gym.
  • Fasted weight training is great for boosting fat oxidation. Which means more fat loss.
  • To get maximum benefits from fasted weight training, you should consume balanced food, including digestive carbs, in your last meal before the workout.
  • There are several pros and cons of fasted weight training. The benefits and drawbacks depend on how you train your body and the duration of your exercise session.
  • Fasted weight training is good if you have a short-term goal. But if you want consistent and healthy progress in weight training, you should prefer consuming meals 2 hours before the workout.

Fasted Weight Training

What is Fasted Weight Training?

If you are reading this, you are probably keen to know everything related to weight lifting while fasting. So, let’s begin with understanding the concept of fasted-weight lighting.

Fasted weight training is a workout where you lift weights in a fasted state (which means you had food four to six hours before training). When you fast, your body gets enough time to digest and metabolize a good portion of food from your last meal, changing your body’s fuel preference from glucose to fat.

During fasting, the hormones like insulin and glucagon change the amount of glucose in the blood and liver. For instance, when blood glucose is high, the body uses the same glucose as fuel to function. On the contrary, when the level of blood glucose subsides, the body burns fat to cover up the lost glucose stored in muscle and the liver. As a result, your body changes its function to maintain the optimum level of glucose in the blood.

Similarly, fasted weight training takes advantage of this function, where your body burns fat to get fuel, helping you get the desired results quickly. Some trainers believe that you burn more fat while training on an empty stomach, and others believe pre-workout nutrition is a must to get the desired results.

How to do Fasted Weight Training?

How to do Fasted Weight Training

To do fasted weight training, the difference between your last meal and your workout session should be five to six hours.

As soon as we consume our meal, our body starts breaking down the food into tiny molecules transported into the bloodstream. These molecules provide essential nutrients to the blood by increasing the body’s insulin levels.

This digestion period, where the body converts food into energy, is called the ‘fed’ state. And this fed state can last somewhere between three to six hours, depending on the kind and amount of food you consumed and your metabolism.

As our body finishes processing the food, blood glucose and insulin levels subside. And this is called the fasted stage. So, if you work out three to six hours after your meal, it will be referred to as training in the fasting condition.

Let us know look at some tips that can help you fetch the maximum fasted weight training benefits.

Make fasted weight training the first thing in the morning

Perform fasted weight training first thing in the morning to maximize results. If you do fasted training in the morning, you’ll see noticeable results in minimum time. This is because your body performs better after proper rest.

Take BCAAs before training

Branched-chain amino acids increase energy, drive muscle growth, boost brain power, aid fat loss, blunt fatigue, prevent muscle protein breakdown and even extend life. The three BCAAs are leucine, isoleucine and valine.

Leucine is the BCAA responsible for boosting muscle protein synthesis after exercise. Valine, the BCAA responsible for bringing more glucose to the muscles as they are stressed, works best when consumed before a workout. Isoleucine works to repair muscle tissue, and it also helps increase energy levels.

The BCCAs include three amino acids, supplying twice as much leucine as isoleucine or valine. These amino acids are supplied in the ratio of 2:1:1 because leucine is good at stimulating protein synthesis and suppressing muscle protein breakdown.

As a result, when you consume this supplement before fasted weight training, it helps suppress muscle breakdown.

Six grams of BCAAs will provide 3 grams of leucine and 1.5 grams of isoleucine and valine.

Consuming 3-5 grams of BCCAs before fasted weight training will help you prevent muscle protein breakdown and increase your performance and muscle growth.

Have a balanced meal

Fasted weight training means exercising three to six hours after the last meal. And to get maximum benefits, your last meal should have a good portion of fats and carbs.

When you balance the carbs, proteins, and fats well, the carbs will be converted into muscle glycogen through breakdown. This glycogen will help you gather the required energy for weight training.

Eat digestive carbs

Consuming digestive carbs should be your priority in fasted weight lifting. When we fast and exercise, our body loses glycogen (glucose stored to be converted into energy). This glycogen is created by our body when it breaks down healthy food, making it essential for you to consume a good amount of digestive carbs in your last meal.

Most importantly, digestive carbs also help in maintaining a healthy hormone level.

Pros and Cons of Fasted Weight Training in Nutshell

People generally get divided into two groups while talking about the pros and cons of fasted weight training. Some people are for it because of its benefits, while others oppose it. Read the pros and cons mentioned below in a nutshell and decide for yourself.



Fasted weight training helps burn body fat quickly

No muscle pump

It boosts your muscle growth

Your muscles can degrade if you indulge in a longer or intense training session.

Fasted weight training boost blood flow to the abdomen

Less energy compromises your workout. So you may not be able make new PRs.

Helps improve the way your body uses oxygen, increasing your endurance level

Increases stress and disturbs your sleeping pattern

Increases insulin sensitivity


5 Benefits of Fasted Weight Training

During fasting, the insulin in your body declines, turning fat reserve into the primary fuel source. Usually, your body uses glucose as energy, but while you fast, it runs out of glucose and starts burning fat to convert the same into a source of energy.

As a result, the ideal condition is created where you put on muscles and burn fat storage during the workout.

Let’s look at some of the most influential benefits of fasted strength training.

Burns body fat quickly

Various studies have shown that while you train on an empty stomach, your body follows a process called lipolysis or fat oxidation, which burns fat to get the required energy necessary to perform a certain workout.

According to a study, if you train your body on an empty stomach, it will burn 20% more fat compared to what you’ll lose in a workout after a meal. This is because once you consume your meal, your body has other energy sources, but during the fasting stage, it uses the stored fat as the primary energy source.

Increases muscle growth

Do you also believe that muscles grow during the workout?

For your information, muscles do not grow while you are working out. Instead, they grow during the time of repair.

So, when we work out, our muscles tear, and once we finish the training, our body starts repairing by sewing those small tears created in the muscles. This process is called protein synthesis.

Protein synthesis is when your body sews the torn muscles and creates new muscle fibers called myofibrils.

Studies reveal that exercising on an empty stomach increases the rate at which your body repairs. The same study clarifies that this happens because when you eat after your workout, your body shows a better anabolic response to the nutrients. And better anabolic response means you can rebuild your muscles at a faster rate.

Increases insulin sensitivity

So, let’s understand how our insulin get’s affected when we work out while fasting. However, before getting into those details, let’s first understand what exactly insulin sensitivity is?

When we eat a meal, our body uses insulin to carry the essential nutrients into the bloodstream. Eating a balanced diet regulates the amount of insulin in our bodies. However, when we overeat, our body starts developing insulin resistance. As a result, a dangerous condition is created, which does not allows insulin to do its job, preventing the transfer of essential nutrients in the body.

Now, let’s understand what happens when we do fasted weightlifting.

When we perform weightlifting while fasting, our body works on limited insulin. As we become consistent with our efforts, our body gets accustomed to working with limited insulin and grows to appreciate its presence.

Now, when you push your body to perform weightlifting on a limited supply of insulin, it becomes more sensitive to insulin levels.

Finally, when you body gets habitual of working on limited insulin, it transfers the essential nutrients to the blood, ensuring better health.

Boosts blood flow to your abdomen

How many of you believe that the lower abdomen is the problem area of your body? Maybe many.

The lower abdomen fat is the hardest to get rid of, and fasted weight training helps target this area efficiently.

Experts believe working on an empty stomach boosts the blood flow in the lower abdomen area, making it easier to lose stubborn fat from this region.

Improves the way your body uses oxygen

According to a study, training your body on an empty stomach increases VO2 max, which refers to how your body uses oxygen.

The better your body performs in using oxygen to its optimum, the better you feel during the workout. Using oxygen to its optimum increases endurance and boosts your performance during workout sessions.

4 Drawbacks of Fasted Weight Training

Fasting and weight lifting can bring both favorable and adverse effects, depending on your level of the workout and the amount of nutrients you consumed in your last meal.

We have already discussed the benefits of fasted weight training, and let us now discuss the possible drawbacks of fasted weight training.

No muscle pump

The energy supply decreases when you fast for long, making you feel less powerful during the workout. However, for muscle building, you need a sufficient dose of energy, which could only be attained from protein and carbohydrates. In addition, muscle pump is achieved from two bodily reactions, including;

Nitric Oxide

Nitric Oxide, obtained from essential amino acids, helps to dilate blood vessels for better blood circulation. However, when you fast for too long, your body lacks the essential amino acids that restrict the pumping of the muscles.

ATP chemical reaction

This chemical reaction is responsible for processing the macronutrients in the pre-workout meals and supplying chemical energy to the muscles. So, if you are fasting, your body won’t have enough carbohydrates to be broken and supplied as chemical energy, making your muscle pump suffer.

When you perform weight lifting while fasting, you fail to provide the required energy to the body, restricting muscle pump during the workout.

Muscle degradation

Maintaining a balance between muscle protein synthesis and muscle protein breakdown is crucial to avoid muscle loss.

Muscle protein synthesis refers to the process where your body breaks down the macronutrients from healthy food, assisting in muscle fiber production.

Muscle protein breakdown is when the muscles use the muscle fiber to get the required energy for weightlifting.

When you do an intense workout while fasting, your muscles can degrade. Muscle degradation happens as a result of your body pulling apart amino acids to help preserve critical blood glucose. For your information, the glucose level in your blood starts decreasing as it finishes digesting the food.

Besides, chronic low blood glucose can also depress the immune system, making your body lose the required energy.

Compromised energy

In exercises like weight lifting, HIIT, etc., your body requires a certain amount of energy, and when you fast, it becomes difficult to put in the required energy.

A study on a certain number of athletes proved that the ones who were given 100 grams of carbohydrates before cycling performed better, showing a longer exhaustion time. In addition, food helped them stay on the bicycle for a long.

So, if you work out in fasted state daily, you’ll probably hate your time with the exercise machines and gradually lose interest.

Elevates Cortisol

Cortisol is a stress hormone that influences the mental health of an individual. In addition, it controls the utilization of carbohydrates, protein, and fat in your body. Working out on an empty stomach puts unwanted stress on your body, making your muscles go through undesirable stress. As a result, cortisol levels rise in your body, which can also cause muscle loss.

Making your body do something that doesn’t makes it feel relaxed puts stress. Exercise puts stress, and so does fasting. Everybody has a limited stress capacity, and when you put more stress than this capacity, you could suffer.

So, it is crucial to provide enough nutrients and sleep to make the body stress-free before the next workout.

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Will Fasted Weight Training Burn Muscles?

Will Fasted Weight Training Burn Muscles

Yes, fasting and weight lifting can burn your muscles and decrease their volume.

When the muscle protein breakdown exceeds protein synthesis, the muscles in your body begin using its fiber as the primary source of energy. This happens due to the lack of macros in your body, which is common when you workout on an empty stomach.

Is it Ok to Lift Weights on Empty Stomach?

Yes and No, this is a tricky question. And to answer it, we need to consider a few aspects.

To conclude whether it is Ok to do fasted weight training, we need to consider your exercise patterns and the type of exercise you perform.

So, if you are indulging in a vigorous workout session, you might not be able to put in the same energy level for long. If it is just a 20 minutes workout or so, you’ll feel energetic, but if your goal is to spend one hour working out in the gym, you might get tired and feel dizzy.

Another aspect that requires your attention is the time of training. If you work out first thing in the morning, you’ll have better energy as you just took a long rest and will be in a fasted state. This is the best time to achieve peak performance.

The more gap you put in between the time you wake up and the time you work out, the more downfall you will notice in your ability to perform.

Does Fasted Weight Training Burn More Fat?

Does Fasted Weight Training Burn More Fat

Yes, fasted weight training helps burn body fat by increasing fat oxidation.

Now, let’s understand what exactly is fat oxidation.

Fat oxidation refers to the burning of fat in the body. It consists of two steps;

  • First, the stored fat is broken down into fatty acids
  • Second, these fatty acids are converted into energy to keep us going.

Now, when you eat your meal, your body converts the carbs into energy and uses them as fuel. However, when you fast, your body is left with no food for energy, and it starts using its own fat for energy, which is called fat oxidation. According to several studies, fat oxidation speeds up the fat loss in the body.

You need to understand that if your body burns more fat than it consumes on a daily basis, it will lose weight. However, if you consume more fat than you burn, you will still gain weight, irrespective of how hard you train. So, it all depends on the number of calories you intake in your meals.

Fasted Weight Training: Yay or Nay?

The experts get divided into two opinions when talking about fasted weight training. One that supports fasted weightlifting and others that don’t. So, let’s look at the explanation of why you should or shouldn’t train while fasting. And we will leave it to you to decide for yourself.

The one that support fasted weight training explain that;

  • You burn more fat while workout out fasted because of fat oxidation
  • Your growth hormone is at its peak, helping you to build muscles.
  • Lifting weights on an empty stomach prevent throwing up during the workout.

Now, the others who are against fasted weight training explain;

  • There’s a fear of muscle breakdown during fasting as you lose lean muscle mass.
  • Your muscles lack the protein to build post-workout.
  • You might feel hungry, and this may distract you during the workout
  • Your body doesn’t contain enough energy to perform high-intensity weight training for prolonged periods.

Now, both explanations are valid to some extent, and we need to break down this information to come to a conclusion.

Fasted weight training indeed increases fat oxidation. Coming to the growth hormone, you should know that it reaches its peak when the body uses fat and carbs as fuel. However, it does not help you gain muscles, at least not at physiological levels. So, it does very little for muscle growth.

You break your muscles faster during weightlifting, and so do you build them. As fast as your muscles break, your body builds new muscles, and this happens as soon as you start eating post-workout. According to a study, strength training doesn’t build muscle until you eat and does not even increase muscle loss.

Coming to the energy perspective, you might not feel as energetic in the gym as you do when you train with pre workout meal.. So, it all depends on what you are accustomed to. A small study revealed that skipping breakfast decreased the individual’s performance in the gym, but this could be because the concerned individuals were habitual of having breakfast before exercise. So, more of it depends on your routine. 

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Concluding Thoughts

Now that you know the perks and risks of weightlifting on an empty stomach, we believe you know what’s right for you. Fasted weight training is good if you have a short-term goal. But people who want to achieve and maintain consistency in weight training should prefer consuming meals before the workout.

We hope you take the right decision for your body. Happy gyming!