Why you should put on your sneakers in the morning before you pick up a spoon

When you wake up in the morning, your body is like an old farmhouse stove: it’s just starting to warm up. In the early hours, your blood sugar is usually lower, and so are your glycogen stores—this is the form of sugar our body stores in muscles and the liver to use later for energy. When these stores are depleted, the body has no other choice but to start burning fat. And that’s the magic of morning workouts on an empty stomach.

In 2013, British researchers published an interesting study in the British Journal of Nutrition, where 12 physically active men ran for an hour on a treadmill: once after breakfast, and the other time on an empty stomach. The result? Those who exercised without breakfast burned as much as 20% more fat than their peers. Twenty percent is not a little—it’s nearly a quarter more fat burned with exactly the same workout!

Although this research was small, it was supported by later studies. In 2015, researchers in the prestigious scientific journal EBioMedicine found, by precisely measuring oxygen and carbon dioxide consumption, that fats burn most intensely when you exercise on an empty stomach, and these processes continue for as much as 24 hours after the workout itself.

But what about women?

Here, too, we have good news. In 2017, a study published in PLoS One proved that fasted exercise benefits women as well. Nine women participated in a 24-hour study where some performed an hour of moderate exercise before breakfast, while others did not. And as measured by the scientific method of calorimetry (which measures how much energy the body uses in a certain period), the group that exercised on an empty stomach burned more fat throughout the day than the group that didn’t exercise.

What does “fat oxidation” mean?

It’s a term often found in scientific articles, but it’s actually quite simple. Oxidation means burning. So, when scientists talk about fat oxidation, they simply mean how the body burns fat stores for energy. And clearly, it burns them more when we train in the morning without food.

Fasting and movement

If you ask our grandmothers how they stayed slender, they’ll tell you something that today sounds like advice from a biohacker conference: In the morning, you should go to the garden or for a walk, and not eat anything (heavy) before. And they’re right.

Fasting—deliberately avoiding food for a certain period—has been present in traditional healing practices for thousands of years. Ayurveda, traditional Chinese medicine, and even old folk customs mention a morning walk or light physical activity before breakfast as a way to wake the liver and detoxify the body.

Although today fasting has become a modern biohacking trend (known as intermittent fasting), it’s actually ancient wisdom that our ancestors used instinctively. First, they worked; then they ate, only after the work was done.

What else affects morning fat burning?

Here comes something that science calls the circadian rhythm. This is the body’s natural internal schedule—as if there’s a built-in clock. This rhythm regulates wakefulness, body temperature, appetite, metabolism, and even hormone levels. According to research from the American National Institutes of Health (NIH), your natural cortisol level is highest in the morning. Cortisol is a hormone that helps release energy. If we harness this hormone with physical activity, the effect on fat burning is even greater.

But what about those who can’t go without breakfast?

Sometimes the feeling of an empty stomach is unpleasant. The good news is, you don’t have to starve completely. If you’re someone for whom even the slightest effort in the morning leads to nausea, you can have something small, like half a banana. No more. This will give you a bit of sugar for initial energy, but you won’t greatly reduce the positive effect on fat burning.

Banana is an excellent choice because it contains natural sugars and potassium, which helps prevent muscle cramps.

What do the numbers say?

Data from the European Journal of Sport Science show that moderate morning exercise without breakfast leads to greater weight loss over time. In a 6-week study, the group that exercised on an empty stomach lost on average 1.4 kg more fat than the group exercising after a meal.

Data from 2022 published by the American Council on Exercise indicate that just 30 minutes of moderate fasted exercise increases fat burning by up to 28% compared to exercising after breakfast.

What about appetite?

Interestingly, working out on an empty stomach does not lead to overeating later on. Quite the opposite. Scientists at Tokyo University discovered in 2018 that people who exercise before breakfast consume on average 300 kcal less later in the day than those exercising after a meal.

This may be explained by the regulation of the hormone ghrelin, which stimulates hunger. In the morning, exercising fasted seems to lower its levels, meaning you’ll be less hungry for the rest of the day.

When is fasted exercise not recommended?

It’s important to emphasize: exercising without breakfast isn’t for everyone. If you’re aiming to increase strength, speed, or muscle mass, exercising on an empty stomach probably won’t give you the best results. Without energy stores in your muscles, it’s hard to perform high-intensity exercises. This also applies to people with medical conditions, such as low blood pressure or hypoglycemia (low blood sugar), where consulting a doctor before changing your routine is essential.

Sometimes grandmothers knew more than laboratories

Today, we’re returning to a practice known for generations: exercising on an empty stomach. Although it used to be recommended just to get the body moving, today we know it’s about activating fat burning, increasing metabolism, and improving the body’s metabolic responsiveness.

If your goal is to lose excess weight, shrink your waistline, and improve your overall well-being at the same time, then consider whether next time you should put on your sneakers in the morning before picking up a spoon.

Maybe the only breakfast your body really needs is still hidden in your fat stores. You just have to use it.

Information on this website is for educational purposes only and is not medical advice.