Thinking of going for a morning run before breakfast? You’re not alone. Fasted running—also known as running on an empty stomach—has become a hot topic among fitness fans and endurance athletes. But is skipping your pre-run snack a smart move or a recipe for burnout?
What is running on an empty stomach?
Running on an empty stomach means you haven’t eaten for at least 10 hours—usually this happens naturally when you lace up your shoes first thing in the morning. It’s different from just skipping lunch or waiting too long after breakfast. For it to count as “fasted,” your body needs to be in a fasted metabolic state, not just low on snacks.
How does your body fuel a fasted run?
When you’re running without any recent food in your system, your body shifts gears. Without its usual supply of quick energy from carbohydrates, it taps into stored fat to power your workout. That’s why fasted running is often linked to improved fat burning.
In fact, studies have shown that running in a fasted state can burn up to 20% more fat during the workout. Some runners also report better endurance after several weeks of incorporating fasted runs into their routine.
But… there are some drawbacks
Before you start skipping breakfast every day, here are a few things to keep in mind:
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Muscle Loss Risk: Running without fuel can cause your body to break down protein—yes, your muscles—for energy. If you’re training to gain strength or maintain muscle, this could be a red flag.
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Weaker Performance: High-intensity runs or intervals? Not ideal on an empty stomach. Your body craves carbs for quick bursts of energy, so you might feel sluggish or underpowered during tough workouts.
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Fat Burn ≠ Weight Loss: Burning fat during your run doesn’t guarantee weight loss. What matters most is your overall calorie balance over time.
Can it improve your stamina?
Here’s where things get interesting. Several studies suggest that fasted running can train your body to become more efficient at using fat as fuel, potentially improving endurance for steady-state efforts like long-distance running. But for sprinting or racing, you’ll likely perform better with some fuel in the tank.
Should you try fasted running?
That depends on your personal fitness goals:
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Trying to burn fat? Fasted runs might help.
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Training for speed or strength? You’ll likely benefit more from pre-run nutrition.
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Focused on consistency and enjoyment? Choose the approach that keeps you feeling energized and motivated.
Some runners love the freedom and simplicity of a sunrise jog without food, while others need a banana or toast to feel human. There’s no right or wrong—it’s about what works for you.
It’s no magix fix
Running on an empty stomach can be a powerful tool—but it’s not a magic fix. Test it out, see how your body responds, and don’t be afraid to switch it up. Whether you run fasted or fueled, the real victory is showing up and putting in the miles.
So, breakfast or no breakfast—just keep running!
