EPOC or Afterburner affect is the new sexy word promoted on personal trainer websites, boot camps and sales jargon behind Orangetheory franchises around the county. The claim that a High Intensity Interval Training (HIIT) style of workout will have an enormous impact on how you burn calories by claiming you will burn an additional 36% extra calories for the next 38 hours. Where do I sign up? Hmmm perhaps snake oil? Time for a EPOC Reality Check
So in other words the claim is that you can do a 20-30 minute Crossfit / Orangetheory style workout at ultra high intensity and burn more calories than the guy who’s doing a 60 minute spin class? Give me a break! But ill let you decipher the research. The EPOC Reality check says otherwise.
I think its important to look carefully at the research and do some easy calculations before drawing a conclusion. There have been a plethora of studies validating what your about to learn. If your still in doubt dig into it on your own. For the purpose of this post I will rehash only the easy to understand studies.
80 Minute treadmill study:
Group 1 A group of people walked the treadmill at 25% of their VO2 Max. (25% VO2 max is equivalent to a casual walk. A person can still workout at talk.
Group 2. Another group of people and had the do a light jog on the treadmill at 50% VO2 max. This group barely broke a sweat. talking becomes slightly fragmented
Group 3. Another group of people ran the treadmill at a vigorous pace representing 75% of VO2 max. This group really worked hard. Talking and running is now difficult.
Without surprise Group 3 saw the greatest EPOC (Afterburn Effect) They burned and average of 150 calories AFTER exercise was concluded. Nice! The research of Afterburn is validated, but what about the number of calories burned? Read on.
The ancillary study calculated that group 3 VO2 Max levels remained elevated by 5% for 24 hours after finishing the 80 minute run.
Now the Science and Numbers:
Consider the average Joe or Jane has an average RMR (resting metabolic rate ) of 70 calories per hour. So take 70 calories X 24 hours = 1680 calories naturally expended per day without exercise.
Now multiply 5% elevation in Afterburner the ancillary study showed to the average RMR of 1680 and your net result is 84 calories… So you burned and additional 84 calories over a 24 hour period by busting your ass running on a treadmill! You got to ask yourself ! Time for another EPOC Reality check
Other studies have shown far smaller percentages in afterburner effect. Other studies have shown that exercising at high levels of VO2 max causes individuals to overeat simple carbohydrates in order to replenish sugar glycogen stores.
The EPOC reality check exposes the embellishments. The value is so ever MINISCULE and OVERHYPED. Your best bet would be to simply forget about it. Dont use exercise as an excuse to over eat and negate calories and do your workouts in moderation without hitting the “puke zone” and please don’t starve your self into a metabolic deficit by under eating.
Rivak Hoffman is a nationally certified fitness professional, fitness writer and researcher committed to uncovering the myths in the fitness industry. He is the founder of Rxfitnesspro.com of Southern California and EverybitfitAZ in Mesa AZ.