Should You Work Out Fasted of Fed

Fasted Workouts: Fitness Hack or Hormonal Havoc?

Guest post by Dr. Pooja

Should you work out on an empty stomach—or eat first? It’s a common question, and the answer isn’t one-size-fits-all. Whether you should train fasted or fueled depends entirely on your goals, physiology, and the type of workout you’re doing.

The Myth of Fasted Fat Burn

One of the most persistent fitness myths is that fasted workouts help you burn more fat. While it’s true that you may burn a higher percentage of fat during the actual workout, that doesn’t necessarily translate to greater fat loss over time. It just means your body is using fat because there’s no glycogen (carbs) available.

Here’s the kicker: When carbs are low, your body can start breaking down amino acids (yes, your muscle!) to make up the energy gap—putting lean mass at risk.

Performance Suffers When You’re Running on Empty

If you’re lifting weights, doing HIIT, or aiming for performance gains, fasted workouts might actually be holding you back. Without fuel, your body can’t hit the same intensity, recover as quickly, or preserve muscle mass as effectively. Over time, this leads to lower-quality workouts and fewer results.

When Fasted Movement Might Be Okay

Not all fasted movement is bad. If you’re going for a gentle morning walk or zone 2 cardio, and it feels good, that’s probably fine—especially if it fits your schedule. But it shouldn’t be your default. And if you’re seeing signs of fatigue, poor recovery, or hormonal shifts, it’s a red flag.

The Power of Pre- and Post-Workout Nutrition

Fueling before and after your workout matters more than most people think. A mix of protein and carbs before you train can help you preserve muscle, boost output, and avoid excess cortisol (aka stress hormone) release.

After your workout, replenishing nutrients—especially if you’re taking a GLP-1 medication like Ozempic or Wegovy—is crucial. These medications blunt hunger, but your body still needs nutrients to recover and maintain muscle.

Your Body Isn’t a Trend

Fasted training is often presented as a shortcut to fat loss or metabolic health, but the reality is more nuanced. In my practice, we look at the whole picture: genetics, lab results, wearable data, lifestyle, and individual goals. That’s how we build a plan that supports real, sustainable metabolic health—not just short-term trends.

4 Common Fasted Workout Myths, Busted:

1. Fasted workouts burn more fat.
   True in the moment—not over time.

2. You need to “earn” your food by working out.
   Dangerous mindset. Under-fueling leads to hormonal chaos and poor results.

3. Fasted workouts improve insulin sensitivity and longevity.
   Possibly—in elite endurance athletes or under strict protocols. Not your average gym-goer.

4. Training fasted is more “disciplined.”
   That’s diet culture talking, not science.

The Bottom Line

If your workouts leave you dragging, plateauing, or sacrificing muscle—you’re likely under-fueled. Even a small pre-workout snack, like half a banana with almond butter or a scoop of protein with berries, can make a big difference.

And don’t skip hydration—water and electrolytes are essential for muscle function, performance, and recovery.

Train to build, not just to burn. Let your strategy reflect your physiology, not a fitness trend.