Ask Andrei: Working Out While Fasting?


It’s the age old question: should you eat before a workout, or is it better to workout on an empty stomach?

This is the question that will be explained by my new trainer, the Founder of New Element Training, Andrei Yakovenko - who has also quickly become my guru for just about everything fitness and mindfulness related.

That’s why I’m so thrilled to be sharing a new weekly segment on Mindfully Edible: Ask Andrei.

You’re officially invited to join me in my journey of mindful strength training at NET, and each week I’ll be asking Andrei to share his own knowledge and experiences on a relevant theme.

To launch the very first post in this series, we’re talking FASTING - one of my favourite misunderstood topics that everyone seems to have an opinion on! While I’m not big on relying on subjective opinions to influence my health and lifestyle choices...Andrei’s researched expertise is definitely a perspective I can trust with confidence.

So when booking our first few training sessions together, I couldn’t help but ask him: Should I workout on an empty stomach? (i.e. first thing in the morning and thus before I break my “fast”.

Here’s what he said...

“When we are working out with high intensity, entering the so called fight-or flight response we raise adrenaline and noradrenaline (i.e., epinephrine and norepinephrine). Two things happen. One: we dump exponentially more glycogen out of our muscles and liver (chain of glucose stored as fuel in muscle and liver), which lowers the blood sugar (sugar goes up during the workout, but it dips after the workout) and consequently our insulin. Two, we activate Hormone Sensitive Lipase (HSL). When insulin is down and HSL is up, our adipose (fat) cells break Triglyceride (TAG) bond (one molecule of glycerol and three Free Fatty Acids) and release Free Fatty Acids from the fat tissue into the blood stream so it could be used for energy.”
“So if one's goal is to lose body fat it makes sense to workout fasted and then fast a little more to take advantage of that hormonal state.”

Thus, the answer isn’t a simple yes or no - it really depends on what you’re looking to achieve. Most people - myself included - would also like to gain muscle, and thus fasting before or after a workout probably isn’t the quickest and most suitable way to get there.

If you’d like a more technical and visual approach to the answer, take a look at this:

Fat-flux-645x424 mod.jpg

Andrei summarizes it as so: Intensity Up => more adrenaline => less insulin and more HSL => breaking down Triglyceride bond and releasing Free Fatty Acids from fat cell to blood for energy => less body fat.

While the some of the science goes a bit over my head, the main takeaway is that for the sole purpose of fat loss, working out on a fast, and staying fasted for a couple hours after the workout, may be a suitable strategy you choose to follow - especially if you feel like it’s easier to work out first thing in the morning, either for scheduling reasons or simply because you feel “lighter” and/or more energetic.

With that said, if “bulking up” is your goal, you may want to try another (or at least mixed) approach…

We’ll dive into related topics in another weeks ‘Ask Andrei’ segment!