Home / / Is Fasted Cardio Good For You?

Is Fasted Cardio Good For You?

By Rachael Attard, Updated Nov 13, 2019
is fasted cardio good for you?

Fasted cardio is cardio that is done first thing in the morning on an empty stomach. So is this good for you or not? I will explain, but first we need to cover a few technical details.


Your body uses two main pathways for energy.


One is known as the anaerobic pathway, and your body uses this for high intensity exercise such as HIIT, weights and short interval training. The main fuel for this type of exercise is glycogen (which comes from carbs) and creatine phosphate.


The other pathway is known as the aerobic pathway, and your body uses this for low to moderate intensity exercise such as power walking. The main fuel for this type of exercise is glycogen and fat.

When you start any type of exercise, you will be in this aerobic / fat burning zone. As your exercise intensity increases, you will switch over to the anaerobic pathway at a certain point. The fitter you are, the longer you can stay in this fat burning zone.

When you do cardio at a low to moderate intensity, the body’s preferred fuel is glycogen (carbohydrate) first, and then fats. However, the longer you exercise, the more fat your body will burn.



So to finally answer the question – it IS beneficial to do fasted cardio. This is because you have not eaten anything for a fairly long period of time, so there is not much glycogen (carbs) stored in your body, and as a result, you will end up burning more fat. Fasted cardio works better if you haven’t had a lot of carbs to eat for dinner.

It is best to do low to moderate intensity cardio in the morning. If you tried to high intensity exercise, your body would not have as much energy for it. Therefore you would not be able to do as well during your workout. If you are fit, you would likely still burn more fat doing higher intensity fasted cardio, but it is generally not recommended.

Long, slow cardio is not the most effective way of losing weight. However it IS beneficial to lean out your legs. You will not gain muscle doing this type of exercise, but you won’t necessarily lose muscle either. Read more about how to use fasted cardio to lean out your legs here.

Find out more about my workout and nutrition program that is tailored to slim down and tone your legs here xx

Picture of Rachael

Rachael is an Australian born certified personal trainer and nutritionist who holds a Bachelor degree in Science.

After struggling for years to find an exercise and diet program that is tailored to women striving for lean and toned body with no bulk she designed her Lean Legs Program. This program is tailored to each body type and focused on helping women get toned but feminine bodies, without getting bulky.

Her mission is to empower women and help them stay in shape in a healthy and balanced way.

Leave a Reply

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.

39 comments on “Is Fasted Cardio Good For You?”

    lisa says:

    Hi, nice article! ive read that exercising without eating breakfast keeps your metabolism slow so you burn less calories. so if i walk in a fasted state does it actually matter that my metabolism is slow and will i burn fat?

      Marina - Lean Legs Support says:

      Hey lovely,

      Thanks for reaching out!

      Actually, studies say that there is no difference in calories burned over 24 hours between people who eat or skip breakfast. So to answer your question, your metabolism won’t slow down if you skip breakfast and do fasted cardio and you will burn more fat if you keep your body in the fat burning zone :)

      Let me know if you have any other questions!


Privacy Preference Center


Necessary cookies for the website to function.


These cookies are used to provide an enhanced experience for website visitors, and to collect analytics data.