Running on an empty stomach is a question that many runners ask themselves. It is a very personal question that depends on the individual’s tastes. It is up to each individual to assess whether it is suitable for their body depending on their physical condition.
In this article, we would like to explain what happens in the body when you run on an empty stomach so that you can assess whether this practice is good for you or harmful to your sporting goals. We also give you some basic recommendations to follow if you decide to give it a try, such as the importance of providing your body with the necessary nutrients after the wear and tear caused by running.
What do we mean by running on an empty stomach?
Running on an empty stomach means running without having eaten any food for several hours. It is usually done when we get up after a night’s rest before breakfast.
You will also run on an empty stomach if you go out for a run six to eight hours after your last meal, for example, if you run in the evening and have not eaten anything since breakfast.
Is it a good idea to run on an empty stomach?
There is no single answer to this question. It depends on the individual and the goal you are aiming for. It is crucial to remember that running on an empty stomach can be counterproductive if, for example, you want to increase your endurance level.
Most people who choose to run on an empty stomach have a clear objective: to burn fat. When we run without having eaten anything for four to eight hours, the carbohydrate levels in the liver are minimal, and, as a result, the body turns to stored fat for fuel. However, this process is not so simple.
Although the metabolic process is complex, a simple explanation is that fats, which we store as triglycerides and derive fatty acids, need the oxidation of carbohydrates to be used as fuel.
But what happens if the carbohydrate level is minimal because we are fasting? A process known as ketosis begins. In the absence of glycogen, which is how the body stores carbohydrates at the muscle level, muscle fibres are degraded to provide sufficient energy.
Therefore, to increase muscle mass, it is not advisable to run on an empty stomach because, as we have explained, if a process of ketosis occurs, what we will achieve is to degrade the muscle fibre.
In other words, the burning of fat can lead to the loss of muscle mass. An example of this is the so-called ketogenic diet. These are diets with an absence or minimal intake of carbohydrates which, in the medium term, lead to a significant loss of water and muscle.
Does running on an empty stomach make you slim?
We have already explained how the breakdown of body fat requires burning carbohydrates, albeit through the analysis of muscle tissue. This might make us think it is optimal to lose fat, but it is not that simple.
Running on an empty stomach should be done at a low intensity so that the body gradually consumes fat and reduces muscle glycogen expenditure.
If we decide to run at a medium or high intensity, the scarce glycogen stores are rapidly depleted, and the body turns to other sources of energy, such as protein. This process often results in dizziness, fatigue and weakness, forcing you to stop exercising.
To lose weight, you need to consume more calories than you take in, so running at high intensity is better. It is not recommended to do it on an empty stomach for the reasons mentioned above. Since running on an empty stomach must be done at a low intensity, the energy expenditure is also ordinary.
To increase muscle mass, it is also not advisable to run on an empty stomach because, as we have explained, if a process of ketosis occurs, what we will achieve is to degrade the muscle fibre.
What you should bear in mind if you decide to run on an empty stomach
If you try running on an empty stomach, it is advisable to follow some tips to avoid the risks inherent in this practice.
- Do it progressively. You can start with a short fast of about four hours and work up to eight hours without food. This preparation is essential because of the risk of dizziness, vomiting or even loss of consciousness due to low blood glucose.
- The intensity of the exercise should be low enough to converse with another person without any problems.
- The duration of exercise should not exceed sixty minutes.
- Even if you run on an empty stomach, drink a glass of water before you start. It is essential to stay hydrated.
- Always carry something to eat if you feel dizzy or faint.
- After running on an empty stomach, you should eat well to rehydrate, replenish your glycogen levels and nourish your tissues. Your first post-workout meal should include carbohydrates and protein.
- Contribute to muscle recovery with a food supplement such as Orgono Sport Recovery Supplement 1L, specially designed for athletes, formulated with organic silicon and glycine, ingredients known for their role in strengthening tissues. It is highly recommended in states of stress and muscle and joint wear.
Running on an empty stomach is a personal decision for each runner. Some people prefer to run before breakfast, and if done at low intensity and for a reasonable time, it is not an inadvisable practice. If this is your case, ensure you are well hydrated and always carry something to eat if you suffer a slump.