Excess Post-Exercise Oxygen Consumption (EPOC)
Excess post-exercise oxygen consumption is a measure of the amount of oxygen consumed after the cessation of exercise. A great analogy of this concept is presented on ACE fitness’s website. They conclude that the excess post-exercise oxygen consumption that occurs in our body’s after the cessation of exercise is analogous to what happens to a car after you’ve finished a road trip and have parked it in your garage.
Once you put the car in park, the engine is still very hot, the tires are still warm, as are the brakes. It takes time for the car to cool down and acquire a state of homeostasis if you will. The same can be said for the individual who engages in any sort of demanding exercise. Say for instance you went for a jog. Once you stop jogging and the workout is over, you still can’t help but continue to breath heavily. This may occur for several minutes after the cessation of exercise .
What’s very interesting about excess post-exercise oxygen consumption is that the greater someone’s VO2 max is, the better their excess post-exercise oxygen consumption will be. In other words, the better shape you’re in, the better your excess post-exercise oxygen consumption will be. Looking at an extreme example, if you are a very conditioned athlete, you will be able to recover much more quickly from intensive exercise than someone who is sedentary. By the way, VO2 max is the maximal amount of oxygen that one can consume. This value can be used as a representation of an athlete’s condition.
What is oxygen deficit?
There are some other terms that we should cover here when discussing excess post-exercise oxygen consumption. One very notable term is oxygen deficit. Oxygen deficit is essentially the difference between someone’s VO2 for an entire exercise time period at steady state and their actual VO2 for the entire exercise time period. Steady state exercise is a condition during exercise where the needs of oxygen from working muscles cells are met by the oxygen being brought in by circulation so that metabolic pathways like glycogenolysis and the Krebs cycle can occur.
Oxygen deficit is the value that will be observed when someone is actually engaging in exercise. Depending on how conditioned you are, your ability to reach steady state may occur very quickly, may take a very long time, or may not even occur at all throughout the duration of your exercise session. So, steady state exercise will occur as only a fraction of the entire exercise session.
Why we experience excess post-exercise oxygen consumption
We experience excess post-exercise oxygen consumption due to many different reasons. The most obvious of reasons as to why this is so is due to the fact that your heart rate is still very high after the cessation of exercise. It takes some time for your heart to go back down to your resting heart rate, depending on the type of exercise you endured and how intense it was. The heightened heart rate after exercise means that there is still a high demand for oxygen.
Some other reasons as to why we experience excess post-exercise oxygen consumption are due to the fact that your body is still in “fight” mode after exercise. Besides your heart rate being heightened, your blood pressure is also still relatively high as well. In addition to this, you still have numerous metabolic pathways heavy at work even after exercises ceases. The Krebs cycle, glycolysis, the electron transport chain, and many other metabolic pathways are all still working even as you stop exercising.
Types of exercise to induce excess post-exercise oxygen consumption
Theoretically, any type of exercise would induce excess post-exercise oxygen consumption, even if only minutely. With that being said, it’s apparent that you would need to look at a plethora of different factors when trying to predict just how much someone would experience excess post-exercise oxygen consumption and how it would affect them.
Typically, aerobic exercise would induce the most excess post-exercise oxygen consumption in someone due to the great demand that such exercise puts on the cardiovascular system. Some other factors that would pose to be significant when looking at what could affect someone’s excess post-exercise oxygen consumption would be their fitness level, whether or not they have cardiovascular disease, pulmonary disease, an injury, etc.
How to improve your excess post-exercise oxygen consumption
If your excess post-exercise oxygen consumption is not where you’d like it to be, then there are many different ways that you can work to improve it. For one, you can try to engage in more aerobic exercise. Some types of aerobic exercises include walking, jogging, hiking, swimming, skiing, biking, fartlek training, some circuit training, and many other modes of exercise. Engaging in these types of exercises would definitely have a significant impact on your excess post-exercise oxygen consumption.
This is not to say that performing anaerobic exercise (weight training) would not allot you the benefits of an improved excess post-exercise oxygen consumption, because it can. However, performing aerobic exercise is typically much better at helping you to improve these types of values, including VO2 max. Essentially, the better condition you’re in, the better your excess post-exercise oxygen consumption will be.
- McCall, Pete. Aug 2014. “7 Things to Know About Excess Post-exercise Oxygen Consumption (EPOC).” ACE Fitness. https://www.acefitness.org/education-and-resources/professional/expert-articles/5008/7-things-to-know-about-excess-post-exercise-oxygen-consumption-epoc