Training on an empty stomach or after eating

The question of whether to train on an empty stomach or after a meal has long been controversial in the fitness world. The issue is not clear-cut, and much depends on the training goal and individual preferences of the person exercising. It is important to distinguish between fat reduction in people who do not have built muscle mass and body sculpting by people with significant muscle mass, such as bodybuilders. Both approaches require different strategies and solutions.

1. Training on an empty stomach – do we really burn fat?
2. What happens after training on an empty stomach?
3. Aerobics – are they always beneficial?
4. Differences between building mass and reducing fat
5. Training quality and muscle protection
6. Pre-workout meal and fat burning
7. Training after a meal vs training on an empty stomach
8. Benefits of training on an empty stomach
9. My advice and suggestion
10. Summary

Training on an empty stomach – do we really burn fat?

Training on an empty stomach is particularly popular among people who want to reduce body fat quickly. Scientists have shown that training on an empty stomach reduces intramuscular fat stores (IMTG), which may suggest that the body uses readily available energy during exercise. However, it is worth remembering that these fat reserves do not have a significant impact on the figure, as they are not directly visible and do not affect the aesthetics of the body.

What happens after training on an empty stomach?

Although the body uses intramuscular fat during training on an empty stomach, these reserves are quickly replenished after exercise, sometimes even in excess. The body, preparing for future challenges, stores more intramuscular fat to meet future energy needs. This process may be beneficial for endurance athletes, but it is not optimal for bodybuilders or people seeking to reduce subcutaneous fat.

Aerobics – are they always beneficial?

Intense aerobic training can lead to a reduction in body fat, but too much of it can have a negative impact on muscles and the nervous system. The body adapts to new conditions by learning to obtain energy from other sources, which can lead to a reduction in muscle mass. Therefore, bodybuilding requires finding the right balance between strength and aerobic training.

Differences between building mass and reducing fat

Building muscle mass requires a calorie surplus, large amounts of protein, rest and intense strength training. On the other hand, the process of fat reduction involves a calorie deficit, increased protein intake and additional aerobic and interval training. An inherent part of reduction is also the loss of some muscle mass, which is caused by a lack of sufficient energy and intense endurance training.

Training quality and muscle protection

Training on an empty stomach may carry the risk of muscle loss, especially if the exercises are intense or prolonged. Scientific research shows that training without a prior meal leads to significantly greater muscle protein loss. In one experiment, 60 minutes of training on an empty stomach resulted in a loss of 14 g of muscle protein, which, with repeated sessions, can lead to noticeable losses in muscle mass.

Pre-workout meal and fat burning

Eating a meal before training can significantly increase energy expenditure, which is a result of the thermic effect of food. Studies show that consuming protein before training not only increases fat burning during exercise, but also speeds up metabolism for several hours after training. Therefore, people who train and want to maximise fat burning should consider eating a protein-rich meal before their training session.

Training after a meal vs training on an empty stomach

Research by Antonio Paoli and other scientists indicates that training after a breakfast meal (containing protein, carbohydrates and fats) is more effective at burning fat than training on an empty stomach. People who ate a meal before training burned more calories and fat not only during exercise, but also for several hours after it was over.

Benefits of training on an empty stomach

Training on an empty stomach can have certain benefits, especially when it comes to metabolic adaptation. Studies have found that training on an empty stomach increases the activity of the SIRT1 protein, which is responsible for regulating carbohydrate and lipid metabolism, protects the cardiovascular system and reduces the accumulation of visceral fat. However, it should be noted that these benefits may be more relevant for endurance athletes than for bodybuilders.

My advice and suggestion

If your goal is to build muscle mass, it is better to avoid training on an empty stomach. Instead, it is worth eating a meal rich in protein and carbohydrates, which will better protect your muscles and increase your performance during training. If, on the other hand, you want to reduce body fat, training on an empty stomach can be an effective strategy, provided that it is not too intense and lasts no longer than 30 minutes.

Summary

The choice between training on an empty stomach or after a meal depends on your individual training goals and the type of activity. Training on an empty stomach can accelerate fat burning, but it carries the risk of muscle loss. Training after a meal, on the other hand, promotes better muscle protection and increases performance. It is important to understand that each strategy has its pros and cons, and optimal results can be achieved by tailoring your training plan to your individual needs.

Sources:

Antonio Paoli i in., Exercising fasting or fed to enhance fat loss? Influence of food intake on respiratory ratio and excess postexercise oxygen consumption after a bout of endurance training. PubMed: https://www.ncbi.nlm.nih.gov/pubmed/21411835

Guillermo Escalante i in., Fasted Versus Nonfasted Aerobic Exercise on Body Composition: Considerations for Physique Athletes. ResearchGate: https://www.researchgate.net/publication/341494761_Fasted_Versus_Nonfasted_Aerobic_Exercise_on_Body_Composition_Considerations_for_Physique_Athletes