Let me tell you a story. A couple of years ago I went to a small local gym to experience the promise of a unique workout. The trainer pushed me to Cardio extremes my poor old-lady body could hardly manage. As I stumbled off the treadmill, he cheerily informed me that not only had I burned 900 calories, but I would continue to burn another 500 over the next 24 hours. I left scratching my head, wondering how many clients he was selling on this magic math. While I knew through a VO2 Max test I could determine my calorie consumption throughout a workout, I couldn’t help but wonder how to quantify the calories burned after a workout.
There are some real advantages to working with really smart people – especially when they are curious problem solvers. I took my question to Dr Orr, founder of KORR Medical Technologies, who explained to me the principles of EPOC. Calories burned after a workout is “excess post-exercise oxygen consumption (EPOC)”, sometimes called “after-burn.” The physiology is based in the science that oxygen is required for oxidation of fuel. In the most simplistic terms, during high intensity exercise, the workload being exerted can exceed the body’s ability to deliver oxygen, thereby creating an energy “debt” which will be paid back over the following few hours.
Dr Orr took my query and started researching the data. Eventually he was able to derive a formula to determine EPOC based on an individual’s VO2 Max. Groundbreaking! He found that EPOC is highly dependent on the duration and intensity of a workout. Specifically, a workout needs to be at 30% of VO2 Max for at least 20 minutes.
Next step, we added the calculation to our CardioCoach app so we can calculate the data in real time. And you know what? I am completed underwhelmed by EPOC. I rarely get more than 100 extra calories from EPOC. Never have I burned anything even close to the wild claims made by that trainer. Not to mention the fact that after his exhausting workout I was so depleted I wanted to consume everything in my path. So for me, EPOC is not worth the hype. But thanks to my CardioCoach app, it’s science, not hype!