I was having a conversation with someone from work yesterday who had an unfortunate incident involving his lunch. Since he typically works out during his lunch hour, we were discussing whether he would walk to somewhere nearby and purchase some food or if he would simply go to his workout as usual. The conversation led to the benefits and disadvantages of working out on an empty stomach. And as with all things in life, there’s a case to be made for either one.
Sometimes, it’s more about HOW you do something than the actual WHAT. In this case, there are times when exercising on an empty stomach is fine. In fact, I’ve often heard that exercising on an empty stomach can lead to a better fat burn, since the only energy the body has to depend on is one’s fat stores. Unfortunately, this isn’t correct.
According to an article on WebMD, working out on an empty stomach will cause your body to use a source of energy that’s readily accessible, which may include breaking down sugars from the muscle tissue, followed by the production of sugar by the liver. Fat stores simply aren’t the go-to secondary fuel that many (myself included) believe it to be. By that logic, training heavily on an empty stomach may inadvertently cause you to sacrifice your own muscles in order to fuel them.
The article goes on to explain that if you’re doing a consistent form of aerobic exercise like running or cycling, doing it on an empty stomach can work. But the overall risks of a fasting workout aren’t worth it. The article suggests consuming small portions of low-glycemic, complex carbohydrates, like steel-cut oatmeal, apple slices or whole-grain cereal without the milk. Click on the article link for more of those suggestions. I won’t list them all here.
From the Diabetes standpoint, a fasting workout can be difficult at best. This is especially true since different types of workouts will affect different people’s blood sugars in different ways. Ain’t Diabetes grand??? It’s a wonderful kaleidoscope of bullshit. For example, if I head out on a long bicycle run and may blood sugar is normal, I can expect to hit a high before I get home. Unless my ride is wildly inconsistent in terms of speed and resistance. Then I’ll have a low. Working out on the punching bag or doing heavy weights will almost always make my levels drop. Unless I suspend or remove my pump, then they’ll sky rocket.
See what I mean? And those conditions may be different for each person. So if we add an empty stomach to the mix, it makes things all the more complicated. Not least of which is the fact that hunger can be extremely distracting. Try focusing on lifting weights or working the bag properly when your stomach won’t stop rumbling. It ain’t easy. Plus, hunger can cause fatigue, dizziness and/or nausea, none of which are ideal during exercise.
The next perspective is the martial arts. If your karate classes are anywhere near as intensive as mine are, the last thing you want is something heavy sitting in your gut, sloshing around and making the bile rise in your throat. This is where that small portion of complex carbohydrates comes in. Give yourself the fuel you need to get a more intense workout in, without the risk of throwing up all over the dojo. Contrary to SOME opinion, projectile vomiting is not an effective means of self-defence. That’s a story for another time…
Bottom line, fueling up before a workout will still allow you to burn fat. In fact, that WebMD article linked above indicates that “If you’re doing a killer workout… non-fasting is better. You’ll get to the fat burn because you’re going to deplete carb stores quickly by working out so intensely. You’ll start burning fat within 16 to 20 minutes.” Since I average workouts at 30 to 60 minutes, I’m getting a burn no matter what.
There you have it; empty stomach = not good. More or less. Some people just flat out can’t exercise with food in their stomach, so there are exceptions to any concept, right? For us Diabetic martial artists, eating the right foods at the right times in the right circumstances is all that it takes. Sounds easy enough… (rolls eyes sarcastically) ☯️