Today we’re going to cover a simple question, but one that’s been hotly debated for years in the fitness world: is there really a significant benefit to doing your cardio training while in a fasted state?
Training on An Empty Stomach: The Pros and Cons
The idea that “fasted cardio = greater fat loss” is one of those memes that starts getting passed around at the gym and ends up taking on a life of its own. Most of its adherents just take for granted that it’s true and never fact-check the science.
Now, there’s nothing wrong with fasted training. If you’re a high-speed dedicated fitness buff who has no problem rolling out of bed and doing your cardio first thing in the morning, that’s great and more power to you.
For a lot of the rest of us “normals”, however, it can be a daunting task. And it’s one that can lead to blowing off cardio entirely if you’ve got it scheduled for the early morning, whereas if you’d scheduled it for later in the day you would have been a lot more likely to actually do it.
So What Does The Science Say?
Surprisingly, there’s very little quality research into this. What research there is lends a little support to the fasted cardio theory, but not enough to make a slam-dunk case for it.
The originating theory
The basic theory is that when you haven’t eaten for a long period — like after sleeping for seven or eight hours — your glycogen and insulin levels will be lower than normal. Your body will then be more inclined to burn through your fat stores to fuel your workout.
It’s an assumption that anyone with a very basic biological and nutritional education can make, but that’s the problem with it — it’s not an idea that sprung from rigorous testing, and just because it makes a basic sort of sense that doesn’t mean it’s necessarily true.
There are a few relevant studies on the subject, but they’re all limited in scope. The most recent and most direct study (done in November of 2014) had a subject group of 20 young women (age 18-35), divided evenly between fasted and fed groups.
They did an hour of cardio three times a week over a period of four weeks. The fasted group ended up losing a little more weight on average, but not enough to be statistically significant.
The study results also would have only had limited application anyway because of the uniformity of gender and age, the fact that women in this age group have natural weight fluctuations due to menstruation, and that four weeks was overall too short of a time frame to draw meaningful conclusions from. It also didn’t have a control to compare both groups to.
An older study on the subject (from 1999) that had participants do their cardio at low intensity found that the fasted group only saw small improvements in weight loss if they were on the treadmill for sessions of more than 90 minutes at a time!
Similar problems of limited demographic representation, time span and lack of control also limit the usefulness of these results.
There are several other relevant studies, but they’ve all found either no difference or such a small difference as to be meaningless.[3,4] It’s nearly impossible for science to answer this question conclusively thanks to the expense and logistics of putting a large, diverse group of people up for the months it would take to get meaningful results.
Do what works for you
So in the absence of conclusive evidence, our position is “do what works for you.” If you’re able to handle 6 A.M. cardio and it seems to be giving you good results, there’s no reason to stop!
The most important thing, however, is that you achieve your appropriate caloric and macronutrient goals (especially hitting your protein number) on a daily basis. Keeping that in line will be more important than any other factor. Measuring food and counting calories with some kind of app has been shown to work incredibly well time and time again, yet too few of us actually do it!
And be sure to check out Myokem’s new mTOR Pro if you do enjoy fasted cardio. mTOR Pro is the industry’s first time-released BCAA supplement that will keep you in an anabolic state for longer during those longer periods of having an empty stomach.
But if you’re simply dreading the sound of the alarm clock and what comes after it, it’ll probably be better for your overall fitness if you move your cardio back to some point later in the day after a meal. You’ll be more likely not to skip out on it, and the extra glucose in your system will help keep you from crashing out early.
Drop weight faster and more focused with Pyroxamine
Regardless of how you do your cardio, it’s always better and more in-focus with a capsule or two of Myokem Pyroxamine. This focus-driven fat burner has an incredible blend of thermogenic ingredients that help stimulate you to work out faster, smarter, and burn fat more quickly.
You can grab a free sample below and feel it for yourself, and compare prices using PricePlow at the bottom of this page.