What happens when you exercise on an empty stomach

Many fitness enthusiasts like to work out early in the morning before breakfast, believing that working out on an empty stomach helps burn more fat. This idea, “fasted exercise,” has some truth to it, but the effects on the body are more complex than most realise.

Why fasted exercise may increase fat burning

Exercising on an empty stomach means your body has less readily available glucose, its main source of energy. This means the body could start using up the fat stores to meet energy requirements.

Some studies have shown that fasting before aerobic exercise can increase fat burning during the exercise. But that does not necessarily mean you will lose more weight in the long term than if you exercised after eating.

Firstpost spoke with Dr Dharmendra Kumar, Senior Consultant, Internal Medicine, Amrita Hospital, Faridabad, who shared with us his expert inputs on the same.

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Impact on exercise performance

Furthermore, exercising on an empty stomach can affect performance.

“Low blood sugar levels can cause fatigue, dizziness, headaches, poor endurance and concentration during exercise,” says Dr Kumar.

“Fasted workouts may be appropriate for some healthy individuals engaged in light to moderate physical activity. However, adequate fuel is often required for high-intensity workouts, strength training or long exercise sessions," he adds.

“Exercise without adequate energy stores can cause fatigue, a decrease in performance and, in some cases, even a heightened risk of injury,” shares Dr Kumar.

Who should be careful?

Some groups should exercise particular caution.

"Working out on an empty stomach can be harmful for people with low blood pressure, diabetes, heart conditions and those taking medicines that influence blood sugar levels. They should get medical advice before trying any workouts in a fasted state," mentions Dr Kumar.

Don’t forget hydration

Hydration matters, too.

“Many people wake up mildly dehydrated and exercising without drinking fluids can put additional stress on the body, especially in hot weather," states the doctor.

The best approach

The best approach depends on your individual health status, fitness goals, and workout intensity.

A light pre-exercise snack, such as a banana, yoghurt or a handful of nuts, can often provide enough energy without causing discomfort.

More important than jumping on fitness trends is listening to your body and sticking to a balanced nutrition plan.