Fasted Training: Good or Bad Idea?

What is Fasted Training?

We talk about fasted training when the workout is performed after a fast of at least 12 hours, meaning without having eaten or consumed caloric beverages, only water.

Fasted exercise raises a number of questions, particularly regarding potential weight loss optimization.

It's time to separate fact from fiction!

What Happens in Your Body During a Fasted Session?

When you do your session fasted, usually in the morning upon waking, your body cannot draw energy from a recent meal, so it must use its reserves.

Since your main energy source is glucose, your body starts by drawing from the glucose present in the blood. When this stock decreases, it uses the glycogen stored in the muscles and liver. These reserves being limited, when their level becomes insufficient, the body then turns to fats to produce the necessary energy.

It's this last step that leads people to believe that fasted training is beneficial for weight loss, but is it really that simple?

The Benefits of Fasted Training

Burning More Fat

Indeed, during a fasted exercise session, you will potentially burn more fat, but be careful, it's not magic!

You will indeed burn more lipids, however, this only occurs when your carbohydrate stock becomes depleted. This will therefore happen after a certain time and a certain training intensity.

Moreover, burning a little more fat during the session doesn't necessarily translate to greater weight loss, especially in the long term. Several studies have demonstrated this by comparing fasted exercise to "classic" practice, showing that changes in terms of weight loss are equivalent (source: Department of Health Sciences, New York University).

If you're looking for an effective weight loss program, I offer you a great free one right here 👉 weight loss program

Promoting Discipline

By doing your session first thing in the morning, training becomes an ingrained habit rather than an option to postpone, which reinforces self-discipline.

Starting the day with a workout also creates a sense of accomplishment. This can improve motivation, self-confidence, and encourage more consistent choices for the rest of the day.

Experiencing Positive Sensations

Some practitioners report more positive psychological and physical sensations during a fasted workout session. Not being in the process of digestion can bring a feeling of lightness, better concentration, or even a boost of energy.

However, these feelings remain very individual and vary depending on the type and level of training, the intensity of the session, as well as personal tolerance to fasting.

The Limitations and Risks of Fasted Training

A Drop in Your Performance

Practicing an intense sports session without having eaten can be demanding on the body. One of the main drawbacks is that in the absence of immediate glucose reserves, it becomes more difficult to maintain high intensity or prolong training, which can limit performance, especially during weight training or sustained cardio sessions.

In some people, prolonged and intense fasted exercise can lead to:

• Faster fatigue of the body
• A feeling of discomfort or dizziness
• Muscle degradation in very long or very intense sessions

Potential Muscle Degradation

If you're used to practicing intense or particularly long sessions, doing them fasted can lead to muscle degradation. During a fast, the body mobilizes its proteins to produce energy when glycogen reserves are low. Moreover, by drawing from the protein stock, you increase the risk of injury, especially if you're a beginner.

A Practice Not Suitable for All Profiles

The practice of fasted exercise is not recommended for beginners, people sensitive to hypoglycemia, or during very intense training. Indeed, training without food intake increases the risk of blood sugar drops, which can cause dizziness, imbalance, and in the most serious cases, loss of consciousness.

What to Implement If I Exercise Fasted?

Good Hydration

Hydration is a key point to stay fit and healthy if you practice fasted exercise. You must hydrate by drinking water before, during, and after your session!

Adapted Nutrition

Listening to Your Body

Knowing how to listen to your body is particularly important during fasted physical activity. You must listen to your fatigue and your sensations! This will allow you to avoid injury but also to face blood pressure drops or hypoglycemia. It's important to reduce the intensity or duration of your sessions if your body demands it and not to ignore the signs.

It's also the best way to realize whether this way of practicing your workouts suits you or not and to adapt accordingly.

Adapting Intensity and Type of Training

As you will have understood, increased fasted exercise can be very difficult for the body. That's why it's recommended, especially when starting this approach, to begin with moderate sessions.

Conclusion: Is Fasted Training Right for You?

Fasted training can be beneficial for some practitioners, but it's not a miracle solution for weight loss. The main advantages lie in improving discipline, appetite management, and potentially better insulin sensitivity.

However, this practice carries risks, including decreased performance, risk of hypoglycemia, and potential muscle degradation during intense sessions. It's not suitable for all profiles, particularly beginners.

If you decide to try it, start gradually, hydrate properly, adapt your nutrition, and above all, listen to your body. The essential thing is to find the training method that suits you best and that you can maintain in the long term.

FAQ – Fasted Training

Does fasted training really burn more fat?

Fasted training can increase the use of fat as an energy source during the session, but this doesn't necessarily mean greater fat loss in the long term.
Weight loss mainly depends on the overall caloric deficit, training consistency, and daily nutrition.

Can you build muscle by training fasted?

Yes, but it's not optimal for muscle gain.
The lack of energy intake before training can limit intensity, load progression, and muscle recovery.
For a hypertrophy goal, it's generally preferable to consume at least a light snack before the session.

Is fasted training dangerous?

Fasted training is not dangerous in itself, but it carries risks for certain profiles: beginners, people prone to hypoglycemia, or during long and very intense sessions.
The main risks are dizziness, discomfort, blood pressure drops, and decreased performance.

Should you take supplements before a fasted session?

It's not mandatory, but some supplements can be useful:

• Coffee or caffeine for energy and concentration
• BCAAs or EAAs to limit muscle degradation
• Electrolytes to avoid dehydration

Supplements never replace proper nutrition.

What type of weight training is recommended fasted?

The most suitable formats are:

• Short sessions (20 to 40 minutes)
• Moderate weights
• Bodyweight exercises
• Light full body or circuit training

Very heavy or high-volume sessions are not recommended.

Can you do cardio and weight training fasted?

Yes, but it's recommended to favor:

• Moderate cardio (brisk walking, light jogging)
• Reduced overall intensity
• Shorter sessions

Combining intense cardio + heavy weight training fasted can be very tiring for the body.

What to eat after a fasted training session?

After training, it's important to replenish reserves:

• Proteins: eggs, chicken, yogurt, legumes
• Complex carbohydrates: rice, oats, sweet potato
• Fruits and vegetables for vitamins and minerals

Ideally within 1 to 2 hours after the session.

Is fasted training suitable for everyone?

No. It's mainly suitable for intermediate or advanced practitioners, accustomed to training and fasting.
If you experience excessive fatigue, discomfort, or a significant drop in performance, this practice is probably not suitable for your profile.

Should you train fasted every day?

No. It's preferable to alternate:

• Light or moderate fasted sessions
• Post-meal sessions for more intense workouts

This allows you to enjoy the benefits without accumulating the drawbacks.

About RPGFitness: RPGFitness is the first French gamified training app that transforms your fitness journey into a real role-playing game. Developed by gaming and bodybuilding enthusiasts, the app combines the most addictive RPG mechanics with professional workout tracking tools.

Join us:

• 🌐 Website: app.rpgfitness.fr
• 📱 Android: Google Play Store
• 💬 Discord: RPGFitness Community (coming soon)
• 📧 Contact: support@rpgfitness.fr