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EPOC: What It Is and Why It's Important

Posted By: Joshua Morgan on 12/29/2011

EPOC: What it is and why it’s important

 EPOC is short for excess post-exercise oxygen consumption.  Basically this is the increased oxygen intake following strenuous anaerobic activity.  For simplicity sake, we’ll refer to anaerobic activity as explosive or power movements that last seconds to less than two minutes in length.  When you think of anaerobic, think lifting weights or sprinting 20 yards versus say going out and running half a mile.  Essentially the body has what text books will refer to as “oxygen debt” following strenuous anaerobic activity.  The reason for this is to repair all the stress and breakdown of the muscles. 

In other words, after you finish training your body needs more oxygen.  Your body must restore that oxygen debt to maintain homeostasis. In essence, your body must return to its pre-exercise state.  It does this by re-oxygenating your blood, restoring the circulatory system, decreasing body temperature, and returning breathing and heart rate to normal.  All these steps are called EPOC, and all these steps take energy.  And, of course, as stated previously, you have an increase in energy and oxygen use for the repair of muscle tissue repair.  So the higher your EPOC, the more calories you’ll burn after exercise. So the more intensity you use when working out, the higher of a calorie burning state you’ll be in.  And notice the word work is in working (out).  When I say working out, I don’t mean strolling into the gym, sitting on a machine, and not putting any effort into the endeavor.

The duration of EPOC is around the 24-48 hour mark.

Why is this important?

EPOC has also been slang-termed as ‘after burn’ and this is to represent that 24-48 hours of increased metabolism which means we have an increase of how many calories we typically burn.  And this is one of the great benefits of lifting weights—EPOC.  So not only are you building muscle but you’re putting your body in a greater caloric burning environment.  Aerobic activity gives very little in terms of the EPOC benefit.  This is why I cringe when I hear of someone spending countless hours on the treadmill in hopes of getting and staying in that ‘fat burning zone.’ 

But really no one really knows where that ‘fat burning zone’ is.  Sure we can get a rough estimate and look at figures and formulas but aerobic activity (or what we often refer to as cardio) will burn some calories while we’re running and that’s about where it ends.  It is my opinion that cardio for fat loss is way overhyped.  And if you’ve read some of my other blog entries you’d know that nutrition is king when it comes to fat loss or muscle gain anyway.  Now I’m not saying don’t get out and get in some cardio, it’s great for the heart. But don’t expect to just use cardio activity as a primary means of fat loss.

What I like about places like Crossfit, Fitness Together, and workout programs that involve high intensity circuits involving weights, you get a lot of work done in a short amount of time and this leads to a lot of EPOC.  And, remember, a lot of EPOC = a lot of calorie burning.

So, in closing, if you’re a Fitness Together member, remember to hug or high five your trainer for making you work hard. 

Yours in Health,

Joshua Morgan

As always, references (because credit should be given where credit is due)…

Crosgrove, Alwyn. Biotest Inc. 2010

Waterbury, Chad. Biotest Inc. 2009