ASK A TRAINER: 'Can You Burn Fat by Exercising on an Empty Stomach in the Morning?'
Hello Everyone. I've been getting a lot of questions in the inbox about food and I have to admit it's making me hungry, especially this one:
"I'm trying to lean up for summer. My buddy told me the best way to get that lean, ripped look is to workout first thing in the morning on an empty stomach. I've been doing that for two weeks and I haven't really noticed a difference. Do I just need to be patient?" -Jesse M., Yonkers, NY
In theory, the empty stomach workout theory operates under the assumption that, without access to other energy sources, your body will tap into fat stored in the body as its go-to energy source that you will burn fat without losing muscle gains.
Here's what you need to understand about how your body creates and uses energy during exercise (or even just to perform everyday movement). Your body makes a chemical called adenosine triphosphate or ATP to create the energy needed for muscular contraction. There are three energy systems your body uses to manufacture ATP. Most movements use some sort of combination of all three systems but movement during exercise usually relies a little bit more heavily on one system or another.
The first system is called ATP-CP (ATP-Creatine Phosphate). Your body uses this for powerful movements that last under ten seconds. (Interestingly, creatine supplements sold in health stores mimic this kind of energy so exercisers can trick the body into performing one last, explosive rep at a point where the body would have otherwise failed.) ATP-CP is actually already stored in muscle so fat is a non-factor with this kind of movement so fasting pre-workout isn't going to help you with explosive movement.
The second energy system is the glycolotic system. We use this system for super-intense movements lasting a few minutes. Your average weight lifting set or sprint during interval training utilizes this system. The energy source to create ATP for this particular system is primarily carbohydrates. Skipping breakfast before this type of activity is going to seriously hinder your performance.