Beyond EPOC: The Afterburn Effect and Calories Burned
Most trainers still believe that the afterburn effect from training is caused by EPOC…but as I discussed in part 3, the EPOC from training is quite small.
We are talking less than 100 calories total for most workouts.
So the majority of the calories burned and fat loss from HIIT and Metabolic Resistance Training must come from something other than EPOC.
Here’s the problem…
Scientists have an easy time measuring calories burned during aerobic exercise, but haven’t found a reliable way to measure calories burned from resistance training.
Marc Perry from Builtlean.com has a detailed interview (opens in a new window) with Dr. Christopher Scott on this exact subject.
Dr. Christopher Scott is an Associate Professor at the University of Southern Maine. He has been called a “pioneer” for his research focusing on the determination of energy expenditure for strength, speed, and power related activities, both during and after exercise.
Marc asks Dr. Scott how energy expenditure for anaerobic exercise is measured. Here’s Dr. Scott’s response…
“Well, this is the problem. There is no gold standard. Everyone recognizes that if you’re going to measure or estimate aerobic energy expenditure, you’re going to measure oxygen uptake. There’s not a person I know who won’t agree with that. Anaerobic metabolism, however, how do we measure that? There is no universally agreed on way to do that, and so anybody who dabbles in this, including myself, it’s going to be controversial.”
We know that activities like MRT work at burning calories.
People who do these activities with a sensible diet are typically lean and muscular…we just don’t really have a way of measuring how many calories are burned from this activity.
Dr. Scott believes we have been underestimating the calories burned during resistance training.
“…we are possibly way off in terms of looking at the total energy expenditure of a weightlifting activity or a sprinting activity.”
He believes that the majority of fat from resistance training is burned during the rest periods of the actual workout.
“…however long the recovery component is, that’s when you’re burning fat. If you add all these intermittent periods together, you’re probably – the rationale that I use to determine energy expenditure, I literally assume that during the recovery from strength, speed and power-related stuff, you’re primarily burning lactate and fatty acids, and that’s where the body composition stuff comes in.”
I believe we should look at the Afterburn Effect as calorie burn and fat loss between sets, NOT the calories burned following a workout (EPOC).
We should also consider calories burned during each set.
Based on research, I believe this is how we should measure the effectiveness of a fat loss workout.
- Calories burned during each set, which we most likely underestimate when it comes to resistance training.
- Calories and fat burned in-between each set. Intensity and duration of sets will affect calorie burn and fat loss of each recovery period.
EPOC from the workout won’t be much and probably not even worth considering (which is why I titled this page “Beyond EPOC”).
Before I discuss the types of exercise that burn max calories, you are in for a treat…
Another cat video!
This one is so bad…it’s good.
That is 40 seconds you are never going to get back.
I’m (kind of) sorry, but you didn’t HAVE to press play.
…and you know you loved it.
What type of exercise burns calories at the fastest rate?
Well…an indicator to look for is any exercise that builds up lactic acid in the muscles.
If an exercise is too brief?
It relies on the ATP-PC system and won’t burn a lot of total calories.
If it is a low intensity exercise you can do for a long time?
It relies on the aerobic system which also means less calories burned per minute.
Why Lactic Acid is a good indicator of high calorie burn.
Lactic acid is produced when glycogen in the muscle is burned during strenuous muscular activity.
So a strong lactic acid burn in the muscles is an indicator of a lot of glycogen (calories) being burned.
It is important to point out that there is a time element involved to produce lactic acid. The effort has to be intense enough for a long enough period of time for lactic acid to accumulate in the muscles.
How long you do an activity often dictates the energy system that is used.
- Less than 30 seconds…mainly Anaerobic (Shot Put, Golf Swing)
- 30-45 seconds…Anaerobic + Lactic Acid (200-400m Sprints)
- 45 seconds – 3 min…Aerobic + LA (400-800m sprints)
- 3 min+…mainly Aerobic (jogging long distances and walking)
Anywhere between 30 seconds and 3 minutes of intense effort will create a lactic acid response.
The rest periods will affect how much lactic acid is produced as well.
In the final section of this article I’ll cover a few different workout setups that will maximize calorie burn.
Part 5 Calorie Burning Workouts