Wellness Wire: What is Fasted Cardio?

When you wake up in the morning, do you sleepily shuffle into the kitchen to grab that morning breakfast and coffee? Or do you head straight to the gym before breakfast?

A topic of controversy in the health and fitness world has been fasted cardio, and whether or not it seriously works. Fasted cardio is working out for 30 to 60 minutes before eating breakfast in the morning. Some swear by it, and others say that it provides no additional benefit.

Let’s first break down the facts about exercise. Glycogen is the stored carbohydrate that we use to fuel our bodies during exercise. We receive glycogen from the foods we eat, helping us to maintain energy levels. But when we workout without much glycogen, such as in the morning, our body will transition to burning the extra fat we have stored, instead of the glycogen. When we eat, our body burns the glycogen right away, instead of the fat.

This is where the controversy starts. Well-known publications, such as Body Building and Men’s Fitness, say that it’s a myth our bodies can burn fat with low levels of glycogen, instead they turn to burning muscle. Others say that if you don’t get more than 8 hours of sleep, it is possible that you’ll have just enough glycogen in your body left to burn this fat.

The type of cardio you are performing in the morning is the other factor when it comes to the benefits of fasted cardio. According to a blog post on Men’s Fitness, when you keep it to a light jog or elliptical session for 45-minutes to an hour, your body will burn more fat than carbohydrates. But, because of the low intensity levels, your body isn’t burning many calories. Without high levels of glycogen, your body won’t have enough energy to perform high-intensity, calorie torching exercises, like sprinting. This specific article on Men’s Fitness advises you not to train on an empty stomach, and surprisingly they aren’t the only ones.

An article from Body Building’s website believes the same thing. They say that, while it is true that fasted cardio increases the amount of fat burning, you would have to perform low-intensity exercises for over 90 minutes before seeing serious fat-burning results from fasted cardio. Furthermore, the rate of fat breakdown needs to be evaluated over the course of a few days, instead of hours. High-intensity workouts cause the greatest fat burning, results but if even if you are fasting before your morning walks, or jogs, you aren’t burning as much fat as you would with sprints. That being said, your body physically can’t perform high-intensity exercises on an empty stomach. Fueling your body before high-intensity exercises (or, prime fat-burning exercises) is a more beneficial way to burn body fat than fasting before cardio because you receive the most out of your workouts.

While some people STILL swear by fasted the cardio, you need to first evaluate your fitness goals. For those trying to gain muscle, fasted cardio may not be your greatest option. Try having a scoop of protein before performing your cardio, such as whey protein, as this is type of protein absorbs quickly into your muscles and can be used for fuel during workouts. For those who aren’t looking to gain muscle, there is nothing wrong with fasted cardio—just don’t expect immediate, or mind-blowing results.

Acknowledge your fitness goals and do your research before jumping on the fasted cardio bandwagon. Like any fitness ‘fad,’ not every routine works for everybody.

What do you think about fasted cardio?

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