In today’s world we are always looking for anything that can give us an edge on burning extra body fat and helping us achieve our health and fitness goals a little bit easier. Doing cardiovascular exercise on an empty stomach (fasted cardio) is something that has been touted as a magic pill for extra fat loss for years and has been common practice of bodybuilders before competitions and used by fighters to help them cut weight. The question is however, does it actually make a difference? Let’s dive a bit deeper into what science has to say about this topic.
As mentioned before, fasted cardio has been used by many people for years in hopes of burning more body fat than if they did the same activity with food in their system. The claim is that since your body has no fuel readily available because you have not eaten, your body will more readily tap into fat stores to fuel your exercise. Is this true? Well, science shows us that yes, it is true. Ok, so is that it? Is that the end of the article? Ha, of course not. While science does show that more fat is used for fuel during fasted cardio it also shows that the body compensates for this higher fat burning by lowering the amount of fat it burns the rest of the day. In a simpler way, whether you have eaten or not before your cardio, it will not make a difference on your fat loss at the end of the day, what is more important for fat loss is how many calories you have eaten.
In order to lose body fat, we must be in a caloric deficit. This is when the energy requirements (calories) needed by our body is greater than what we take in. In order to get the extra energy, we need, our body will break down stored body fat for energy. This is the single determining factor on whether or not we lose weight, not whether we did cardio on an empty stomach or not, or even if we ate a cheeseburger or a kale salad. At the end of the day if you have expended more calories than you have taken in you will have lost some weight that day.
So, what exactly do we do with this information? Does this mean you shouldn’t do fasted cardio? Like so many things in the fitness industry the answer is it depends. If you don’t like eating before exercise, then don’t. If you feel that you have more energy and therefore get a better workout when you eat something beforehand, then do so. It all really comes down to personal preference and what works best for you.
One thing to consider however is that if you were to skip a meal (no matter how large), to do fasted cardio you may end up eating less calories throughout the day because you didn’t eat and that may allow you to be in a caloric deficit. In this example doing fasted cardio would help you lose weight because you ended up eating fewer overall calories. Be careful with this though because you may find that skipping that meal makes you ravenously hungry later in the day (especially since cardiovascular exercise has been shown to increase hunger), and you may end up actually eating more calories than if you ate something small before your workout because you just can’t stop eating.
So, there it is, you do burn more fat during fasted cardio, but……. It doesn’t actually matter. The good news is you can do whatever works best for you and your lifestyle. Afterall, this is what is going to lead to lasting results!