Fasted Cardio: Does it Work?

There’s a ton of debate about whether one should do cardio in a fasted state or not. Some fitness experts swear by it, while others say that it doesn’t make a difference and affects performance adversely.

So, who is right?

They both are… but you need to understand why.

• Why fasted cardio works

When you wake up in the morning, your body is in a fasted state after 6 to 8 hours of sleep. Your glycogen levels will be low and the food in your stomach would have been digested.

Exercising on an empty stomach will make the body tap into its fat stores for fuel because of the low glycogen levels. It also has no food to burn for fuel. Left without a choice, the body will burn fat. That’s what makes fasted cardio so effective. It truly works.

• What’s the catch?

But here’s the catch – you should not do high intensity workouts in a fasted state. Your body will quickly resort to burning muscle instead of fat when the workout is vigorous. It’s because of this, many fitness experts say that exercise in a fasted state affects performance.

You’ll not be able to give the workouts your best effort because your body feels drained and you just don’t have the energy. In fact, resistance training on an empty stomach is not recommended at all.

The only exception here is if you’re on an intermittent fasting diet and will be consuming your calories immediately after the workout.

• Who is fasted cardio for?

This is the most important question. Who will benefit most from fasted cardio? The answer to that is – overweight or obese people who have led a sedentary lifestyle for ages.

Fasted cardio helps you ease into a more active lifestyle and still burn fats without torturing you. Generally, fasted cardio should not be high intensity. In fact, the best type of fasted cardio is a 20 to 45-minute walk at a pace that’s brisk, but you should still be able to hold a conversation.

You don’t want to be gasping for breath. The pace must be only slightly faster than normal. During the exercise, your body will burn fat directly from its fat stores. Once you’re done, the fat burning benefits of the exercise will quickly taper off an hour later and your body will not be burning calories at an accelerated pace.

That’s fine because your diet will be at a caloric deficit and you’ll still lose weight. Most people who are not used to exercise will not be intimidated by this form of cardio and will still see positive results from their efforts. The results will be slower to come, but they will come.

As the weight comes off and they get lighter, they’ll also get fitter and will slowly be able to replace the longer fasted cardio sessions with high intensity cardio sessions that are shorter in duration and done an hour or two after a light meal.

High intensity cardio sessions will leave your body burning fat for 8 to 12 hours after the workouts are over. So, despite them being shorter in duration, you’ll burn more fat overall.

Use fasted cardio to ease yourself into a more active lifestyle and slowly progress from there to more challenging workouts. That’s how you consistently lose weight and get fitter without dreading exercise or hitting weight loss plateaus. There is a time and place for fasted cardio.