24/04/2025
Does Fasted Training Burn More Fat? The Truth Explained
Let’s break down the science, myths, and facts behind fasted training
What Actually Happens During Fasted Training?
When you wake up after an overnight fast:
Insulin levels are low
Glycogen (carb) stores are depleted
Your body is more likely to oxidize fat for energy during steady-state cardio
So yes—during the session, a higher percentage of energy comes from fat compared to fed training
But does this translate to greater overall fat loss?
Fasted vs. Fed Training : The Fat Loss Truth
1. Fat Oxidation ≠ Fat Loss
Just because you're burning more fat during the workout doesn't mean you're losing more fat overall.
Fat loss happens through a consistent calorie deficit over time.
The body may compensate by burning less fat later in the day, or by increasing hunger.
Key Point: It's the net calorie balance over 24 hours—not the fuel source during exercise—that determines fat loss.
2. Performance Might Be Lower When Fasted
Working out without food can lead to reduced energy, strength, and endurance, especially during high-intensity cardio.
This can lead to lower total calorie burn, potentially offsetting the benefits of increased fat oxidation.
Solution: Use fasted cardio for low-intensity sessions (like walking or light cycling), not intense workouts.
3. Muscle Loss Risk (if not careful)
Training in a fasted state—especially with no protein—can slightly increase muscle breakdown.
If you're doing fasted cardio regularly, make sure you’re eating enough protein and recovering properly.
Tip: A small serving of BCAAs or whey isolate before cardio can help protect muscle without ruining the fast.
When Fasted Cardio Might Be Useful
If it fits your routine (e.g., morning walk before breakfast)
For low-intensity steady-state (LISS) cardio
If you feel comfortable and energized without food
As a mental tool to start your day with discipline and movement
When It’s Better to Eat Before Cardio?
If you're doing HIIT, circuit training, or long runs
If you feel dizzy, weak, or lightheaded training fasted
If you're trying to build or preserve muscle mass.
Hope this helps.