Should You Be Doing Fasted Cardio?

If you’re anything like every other follower and client of mine, a common question is “Gina, what do you think about morning fasted cardio”?


What Is Fasted Cardio?

Fasted cardio involves increasing your heart rate without eating beforehand. Is this good, detrimental, safe or just trendy?

It isn’t that simple… There is a time and a place for fasted cardio.

First of all, when we are talking about fasted, let’s keep in mind, that for this post, I am referring to fasted, morning cardio when you have been without food for 6-8 hours (or longer). It is the point where our bodies have stopped processing and breaking down food and insulin levels are low and there isn’t fuel (glycogen) circulating in our blood. When this happens, our bodies have to turn to another source of energy – usually fat for energy.

As a figure competitor, I was big on fasted cardio as my main way of getting in cardio. Not only for the fat burning affects but I believe it is a great way to start your day. In a perfect world, doing some fasted lower intensity cardio first thing, is ideal however not everyone can make that happen due to their obligations with kids, lack of equipment etc. So it isn’t an absolute MUST if your schedule doesn’t permit fasted cardio.


Not all Fasted Cardio is to be treated the same.

Keep in mind, I NEVER recommend High Intensity cardio on an empty stomach. Fasted is a slower steady state cardio vs. jumping right into Tabata sprints. Those higher intensity workouts require more energy and you definitely don’t want to jeopardize hard earned muscle to get you through a workout so keep in mind, not all fasted cardio is treated the same.  Same goes for a marathon runner in training for a race. If it is a long run day, running over 5-6 miles, I would not suggest fasted cardio. You never want to sacrifice muscle thinking you are actually maximizing fat burn. If there is no glycogen in your system, your body can and will tap into muscle for an energy source and that is a big no no!

The Benefits of Fasted Cardio

If your primary goal is to lower your body fat percentage and your go-to workout is low- to moderate- intensity cardio, fasted cardio may offer some great benefits.  You can definitely burn more fat when you are fasted vs. just at your breakfast and now body has those nutrients to pull from for energy.

In simple terms, when you don’t have readily available energy from food, your body has to look for another source.

Fasted cardio may be effective in getting the body to help burn stubborn fat for someone that has been working out regularly for a while. If you can swing it and have the ability to change it up, I am BIG on CHANGE so if you haven’t been doing fasted cardio but have the ability to do so, I suggest you give it a try- just be sure it isn’t high intense cardio.

Reminder- NOT ALL fasted cardio is the same.

I want to hit this point again because people tend to read something “fasted cardio is best for fat loss” however there is so much more to it. The ONLY time I would recommend fasted cardio, if your goal is to maintain muscle, which is should be to maximize fat loss,  is when it is a slower paced cardio. The goal is to stay between 50 and 60% your max heart rate. High intensity workouts do require carbohydrates for quick energy. It is a completely different metabolic pathway your body uses to get quick energy.

If you are attempting fasted cardio before sprints, you may find yourself tired, weak, and possibly light headed. In simple terms, I would not attempt a boot camp class, cross fit workout or high intense session on an empty stomach. You also could run the risk of injury so just don’t do it.

So Is does this go for fasted workouts too?

YES. I would imagine if you are on my quick yet efficient workout program, our workouts are short but they are intense. We need to have a little something to get through our workouts and to maximize our intensity since we are in and out in sometimes 20-25 minutes (max). Circuit training is amazing for fat loss, especially for those that don’t have the time to dedicate a lot of time to duration cardio and a weight workout.

If you cannot do fasted cardio, your second best bet is to eat 20-30 minutes before your workout then get in a killer workout followed by duration cardio then eat post cardio. While you aren’t “fasted”, that is the second best window of opportunity because you have burned through that glycogen from your workout so you are getting the next best “fasted” state.


So Is Fasted Cardio Worth It?

Maybe, it boils down to your goals, time, and what’s available to you. As a mom of 2 without cardio equipment at home and a husband who is a fireman, fasted cardio just isn’t realistic for me however if and when the time presents itself that I can get in a good sweat first thing, I will be back in my fasted cardio groove. For now, I do my best and hit that second best window of fat burning opportunity.

There is so much more to fasted morning cardio … ?

I am a huge believer in getting up and getting yourself moving first thing. If you can rise before the sun and soak up the amazing energy of a fresh new day when the birds are chirping and world is quiet, I believe you kick off your day in the best possible headspace. Fasted morning cardio does so much more for your mind than your body, clearing those energetic pathways, getting your blood pumping, endorphins flowing and mind clear. Beyond the facts of what is “best” for fat loss. I believe that an even bigger component to fat loss is how we live out our day. Fasted morning cardio brings such a calm and stress free element to your day so for this, I am a HUGE fan!

In Conclusion…

Now you have more info, next is to do what is best for you, your lifestyle, your goals and body. There is nothing wrong with trying something new, seeing how you feel and if it works for you or not. The key with anything is consistency so find a routine you can stick to day in and day out and watch the fat melt off.