Fasted Cardio: What Is It and Who Is It For

Fasted Cardio: What Is It and Who Is It For

Fasted cardio is a training method that is regaining popularity as an effective way to accelerate fat burning during cardio workouts, but many people are asking what is it? How do you do it and is it healthy?

Simply put, fasted cardio uses a fasting metabolic state to trigger accelerated fat burning, while also reducing insulin sensitivity and improving glucose tolerance. However, if it’s not done properly and combined with proper nutrition, it can have negative effects on your body and your training. Let’s look at what it is, how it should be incorporated into training and see if it’s right for you.

What is Fasted Cardio?

Fasted cardio is when you engage in a cardio activity while your body is in a fasting state. Sounds pretty straight forward. Right? The fasting state is a metabolic state in your body which occurs when your body has gone a prolonged period of time without consuming calories. That prolonged period is usually between 8 to 12 hours since your last meal.

Fasted cardio shouldn’t be confused with working out in a post-prandial state. Post-prandial means that you have eaten within 1-4 hours of your workout and while you might feel as though you have an empty stomach, this doesn’t mean that your body is in a fasting state. When your metabolism is in a fasting state, low glycogen and insulin levels cause the body to shift away from carbohydrates and switch over to stored fat for fuel. Typically fasted cardio workouts are done in the morning and take advantage of the overnight fast. However, they can be done at any time of the day, if you have already integrated intermittent fasting into your training routine and lifestyle and if you're regularly fasting during the day. The key is to have an 8 to 12 hour window after your meal and before your cardio session.

How Do I do a Fasted Cardio Workout?

Doing a fasted cardio workout is just like doing any other workout, your actual workout doesn’t need to change, you just need to be in a metabolic fasting state. Research indicates that HIT workouts can accelerate fat burning as they trigger fat burning for hours after the workout is complete, unlike the more traditional steady state cardio workout. If you chose low to moderate intensity keep your workouts between 45-60 minutes if you choose HIT style cardio workouts, keep your workout between 15-45 minutes, depending on your fitness level. The bottom line on fasted cardio is that it is recognized as a way to burn fat more effectively, especially for problem areas like the abs, low back, hips and thighs, which are typically harder areas to lose stubborn fat.

Can I Eat Anything When I’m Not Fasting?

The short answer is, no. While it is okay to break your fast after your workout, you still have to moderate your macros and you don’t want to cut out all of the carbohydrates from your diet. Research indicates that while your body may burn stored fat during fasted cardio, the dynamic nature of the metabolism is constantly adjusting for different types of fuel, and research shows that after intense fat burning, your body will make up for it by burning more carbohydrates later in the day. What this means is that you have to plan your meals to support fat burning consistently through the day, week, month or year depending on what your athletic goals are.

Is it Right for Me?

You have to know what your athletic goals are before deciding if fasted cardio is going to work for you. If you want to maximize muscle growth, the answer is no, however if you want to burn fat and lose it faster then your answer is yes. Fasted cardio is right for you if you want to lose overall body fat or if you want to burn fat stores that are harder to target (thighs, hips, low back and abs).

How can I give it a try?

If you’re not sure if fasted cardio is right for you, the best way to find out is to give it a go and see. You should try it for at least four weeks performing your fasted cardio session first thing in the morning three times per week (Monday, Wednesday, Friday). If you’re new to HIT workouts and fasted cardio, try the workout below and see what kind of results you get.

For this workout you can use a treadmill, cycle bike, kettlebell, you can run track or any use other piece of equipment you can easily increase and lower the intensity of your workout on. Spend the first two minutes working up. Don’t worry about the intensity, just get your blood flowing and joints loose. After you’re warmed up, push yourself hard for 60 seconds then recovery between 30 and 60 seconds, then push yourself hard again for 60 seconds. Repeat this cycle for twenty minutes then cool off for anther two minutes before finishing. Your morning fasted cardio workout is complete within twenty-five minutes.


Amanda Ashley
Amanda Ashley - Author

Amanda Ashley has been in the fitness industry for over 20 years and is a yoga instructor, functional movement coach and specialist in performance nutrition. She actively pursues her passion in the gym, on the yoga mat, the running trail and occasionally snowboarding down a mountain. Amanda has helped hundreds of clients reach their goals, through her rigorous training programs and delicious nutrition plans. You can catch up with Amanda on Instagram or Facebook.

Also in Training Ground