The Final Nail in the HIIT EPOC Coffin
Options
Azdak
Posts: 8,281 Member
New blog posted today (http://www.myfitnesspal.com/blog/Azdak/view/the-final-nail-in-the-hiit-epoc-coffin-581439):
After an exercise workout is completed, oxygen uptake (VO2) remains elevated for some time over resting levels. This phenomenon is called, straightforwardly enough, "Elevated Post-exercise Oxygen Consumption" or EPOC. The duration and total amount of EPOC varies according to the duration and intensity of the workout. The increased VO2 means a increase in calories burned after the workout as well.
A frequent rationale for promoting High Intensity Interval Training (HIIT) programs for weight loss is the assertion that HIIT workouts burn more calories for an extended time AFTER the workout. A perfunctory use of the Google will quickly uncover dozens of examples of these claims:
"HIIT increases EPOC (excess post-exercise oxygen consumption) resulting in an elevated fat loss state for up to 24 hours after you finish your workout – something you won’t get from lower intensity exercise."
And another:
"Long, slow, low-intensity cardio will produce a small EPOC effect that will at best, last only a couple of hours after the workout. Basically the 400 calories you burn during the workout will be all that you burn, because the EPOC effect afterwards is negligible. However, studies have shown that after HIIT workouts, the EPOC effect can still be found up to 38 hours after the workout - basically your body is burning fat to fuel the restorative processes for 38 hours AFTER your workout! So, even though you may have only burned 250 calories during your HIIT workout, the total calories burned after will be far greater. Those calories, plus the 250 burned during the HIIT workout surpasses the 400 burned during the slow, steady-state workout by a LONG, LONG way."
Actually, the "studies" point out that these claims are exaggerated, to say the least, and that the effect of EPOC for all workouts is modest at best. There are plenty of good reasons to include HIIT workouts in your routine, but a supposedly elevated EPOC is not one of them.
A 2006 study reviewed all the research that had been done up to that time on EPOC. The authors concluded that the additional calories burned from EPOC for endurance exercise was about 7% of total calories expended during the workout. Calories from EPOC for HIIT workouts were almost double, approximately 13% of total calories during the workout.
LaForgia J et. al. Effects of exercise intensity and duration on the excess post-exercise oxygen consumption. J Sports Sci. 2006 Dec;24(12):1247-64.
Double the calories sounds pretty good, however, when comparing the effects of something like EPOC, one must look at the TOTAL calories burned, not the percentage increase and not the "duration" of the "afterburn". Looking at the actual numbers tells a different story.
80 kg individual does a 60 min endurance workout and burns 640 calories. Add 45 calories for the 7% EPOC for a total of 685.
Same person does a 20 min HIIT workout and burns about 300 calories. Even with the extra EPOC of 13%, that's only an extra 40 calories, for a total of 340.
There is no "afterburn" that is going to make up those extra 300 calories.
(For a more in-depth discussion of the LaForgia study, see Lyle McDonald's excellent review:
http://www.bodyrecomposition.com/research-review/research-review-effects-of-exercise-intensity-and-duration-on-the-excess-post-exercise-oxygen-consumption.html)
More evidence was presented in a recent article on the website of the National Strength and Conditioning Association. Several studies were reviewed (including the LaForgia study already discussed) and showed that, even when EPOC remains elevated for 9 hours following a HIIT workout, total calories burned from EPOC only ranged from 18 to 80 calories TOTAL. The only exception was a recent study from Appalachian State University that reported a total EPOC of 190 calories over 14 hours).
As if that weren't enough, a review article published by Melanson et al in 2009 showed that exercise training does not affect 24 hour total body fat oxidation, even though it increases fat metabolism in muscle.
Exerc Sport Sci Rev. 2009 April ; 37(2): 93–101. doi:10.1097/JES.0b013e31819c2f0b.
Other studies have shown either no difference in the 24-hr rate of fat use following exercise, regardless of intensity, or, even when there was a small increase in fat oxidation following high-intensity exercise, the total amount of fat burned was trivial.
The conclusion of the NSCA article was that research:
"...suggests that EPOC is not a primary contributor to the energy cost of exercise and that it does not alter substrate use enough to be of consequence in a weight loss program."
Again, the purpose of this is not to denigrate HIIT workouts. They can play an important role in many workout programs, and, when the time comes, they are essential in order to accomplish significant body recomposition. However, like so much else in the fitness world, the benefits of HIIT are sometimes overhyped and their application frequently overgeneralized. People need different types of workouts depending on their age, body fat levels, fitness level, fitness experience and overall health. When starting a weight loss program, total energy expenditure is still a primary goal of the exercise component. Endurance cardio workouts, submaximal interval workouts, and even endurance strength workouts are usually the better choices for beginners.
After an exercise workout is completed, oxygen uptake (VO2) remains elevated for some time over resting levels. This phenomenon is called, straightforwardly enough, "Elevated Post-exercise Oxygen Consumption" or EPOC. The duration and total amount of EPOC varies according to the duration and intensity of the workout. The increased VO2 means a increase in calories burned after the workout as well.
A frequent rationale for promoting High Intensity Interval Training (HIIT) programs for weight loss is the assertion that HIIT workouts burn more calories for an extended time AFTER the workout. A perfunctory use of the Google will quickly uncover dozens of examples of these claims:
"HIIT increases EPOC (excess post-exercise oxygen consumption) resulting in an elevated fat loss state for up to 24 hours after you finish your workout – something you won’t get from lower intensity exercise."
And another:
"Long, slow, low-intensity cardio will produce a small EPOC effect that will at best, last only a couple of hours after the workout. Basically the 400 calories you burn during the workout will be all that you burn, because the EPOC effect afterwards is negligible. However, studies have shown that after HIIT workouts, the EPOC effect can still be found up to 38 hours after the workout - basically your body is burning fat to fuel the restorative processes for 38 hours AFTER your workout! So, even though you may have only burned 250 calories during your HIIT workout, the total calories burned after will be far greater. Those calories, plus the 250 burned during the HIIT workout surpasses the 400 burned during the slow, steady-state workout by a LONG, LONG way."
Actually, the "studies" point out that these claims are exaggerated, to say the least, and that the effect of EPOC for all workouts is modest at best. There are plenty of good reasons to include HIIT workouts in your routine, but a supposedly elevated EPOC is not one of them.
A 2006 study reviewed all the research that had been done up to that time on EPOC. The authors concluded that the additional calories burned from EPOC for endurance exercise was about 7% of total calories expended during the workout. Calories from EPOC for HIIT workouts were almost double, approximately 13% of total calories during the workout.
LaForgia J et. al. Effects of exercise intensity and duration on the excess post-exercise oxygen consumption. J Sports Sci. 2006 Dec;24(12):1247-64.
Double the calories sounds pretty good, however, when comparing the effects of something like EPOC, one must look at the TOTAL calories burned, not the percentage increase and not the "duration" of the "afterburn". Looking at the actual numbers tells a different story.
80 kg individual does a 60 min endurance workout and burns 640 calories. Add 45 calories for the 7% EPOC for a total of 685.
Same person does a 20 min HIIT workout and burns about 300 calories. Even with the extra EPOC of 13%, that's only an extra 40 calories, for a total of 340.
There is no "afterburn" that is going to make up those extra 300 calories.
(For a more in-depth discussion of the LaForgia study, see Lyle McDonald's excellent review:
http://www.bodyrecomposition.com/research-review/research-review-effects-of-exercise-intensity-and-duration-on-the-excess-post-exercise-oxygen-consumption.html)
More evidence was presented in a recent article on the website of the National Strength and Conditioning Association. Several studies were reviewed (including the LaForgia study already discussed) and showed that, even when EPOC remains elevated for 9 hours following a HIIT workout, total calories burned from EPOC only ranged from 18 to 80 calories TOTAL. The only exception was a recent study from Appalachian State University that reported a total EPOC of 190 calories over 14 hours).
As if that weren't enough, a review article published by Melanson et al in 2009 showed that exercise training does not affect 24 hour total body fat oxidation, even though it increases fat metabolism in muscle.
Exerc Sport Sci Rev. 2009 April ; 37(2): 93–101. doi:10.1097/JES.0b013e31819c2f0b.
Other studies have shown either no difference in the 24-hr rate of fat use following exercise, regardless of intensity, or, even when there was a small increase in fat oxidation following high-intensity exercise, the total amount of fat burned was trivial.
The conclusion of the NSCA article was that research:
"...suggests that EPOC is not a primary contributor to the energy cost of exercise and that it does not alter substrate use enough to be of consequence in a weight loss program."
Again, the purpose of this is not to denigrate HIIT workouts. They can play an important role in many workout programs, and, when the time comes, they are essential in order to accomplish significant body recomposition. However, like so much else in the fitness world, the benefits of HIIT are sometimes overhyped and their application frequently overgeneralized. People need different types of workouts depending on their age, body fat levels, fitness level, fitness experience and overall health. When starting a weight loss program, total energy expenditure is still a primary goal of the exercise component. Endurance cardio workouts, submaximal interval workouts, and even endurance strength workouts are usually the better choices for beginners.
0
Replies
-
Oh, I sincerely hope people hear this and it puts the claims of extra burn to bed once and for all.
But, I fear, it won't.0 -
great post. Bumping for friends list.0
-
Thanks for posting. I actually remember reading Lyle McDonald's article on this and being quite shocked. Like so many claims in the fitness industry, EPOC sounded great. More bang for your buck. Two birds; one stone. Less is more. All that jazz.
All that bs, more like.0 -
I still prefer a HIIT workout for 30 minutes over hours of exercising, but I do it for the ability to fit exercise in rather than the EPOC.0
-
Same.
As Azdak says it will differ for different people.
Can't go past HIIT stuff for increasing Vo2max IMO.0 -
I still prefer a HIIT workout for 30 minutes over hours of exercising, but I do it for the ability to fit exercise in rather than the EPOC.0
-
Interesting, thanks! Just goes to show, if it sounds too good to be true, it probably is...0
-
I still prefer a HIIT workout for 30 minutes over hours of exercising, but I do it for the ability to fit exercise in rather than the EPOC.
The fitness benefits of HIIT are unequivocal.0 -
Unfortunately "parroting" trainers in the fitness world still pass EPOC burn as legit information. The fitness industry needs to quit BSing people. Thankfully I'm not one of those trainers that pass on misinformation like this. Thanks again Azdak.
A.C.E. Certified Personal and Group Fitness Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness industry for 30 years and have studied kinesiology and nutrition0 -
good post, been telling(or trying to tell) people this for ages.
I still do HIIT for the record, as it's more fun than traditional cardio.0 -
Great post. HIIT is perfect to up the intensity without higher risk of injury (like running faster for exemple) but that is it.0
-
Can't beat HIIT for getting in a solid workout in a shorter amount of time. Also, if you play sports it's a great way to train those "fast twitch" fibers and better your sprints and short distance bursts. Other than that though, it's just another form of exercise. No magical powers.0
-
Good stuff. I had not seen anyone make the EPOC claim for quite awhile.0
-
Just to repeat: the article is about HIIT and the overhyped EPOC claims only--HIIT workouts for fitness are extremely effective when applied properly--for both improving and maintaining fitness.0
-
Bump to read tomorrow.0
-
The issue is that this is only relevant to weight loss which isn't where most of the benefit to HIIT lies.0
-
Either way, I'm not going to do it. LOL0
-
The issue is that this is only relevant to weight loss which isn't where most of the benefit to HIIT lies.
A.C.E. Certified Personal and Group Fitness Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness industry for 30 years and have studied kinesiology and nutrition0 -
Yeah, I never bought the EPOC thing.
But HIIT is awesome. Benefits for me:
Specificity - on stage, I may be asked to do something that raises my heart rate for a short time, but I'll never be asked to run for an hour"
Mental benefits - HIIT is fun, and makes me feel refreshed and warmed up and keeps my mood elevated
Convenient - I can pull out the speed rope and bang out 20 mins of double unders, then take a shower and get dressed, in half an hour
Appetite suppressant-like effect - an hour of jogging makes me really freaking hungry. HIIT seems to make me less hungry0 -
HIIT is working wonderfully for me................. specially for weight loss, increased metabolism and cardiovascular health.
What more can I ask ! So I don't care about the EPOC factor. It's working, I enjoy doing it, love the high of watching my heart rate soar, love it that I am done within 20 minutes.
We are all different with different likes and dislikes.
I have a funny feeling that I have read this article somewhere else about a month back when I was doing research on the pros and cons of HIIT. Oh yeah.............. HIIT does surely have some cons.0
Categories
- All Categories
- 1.4M Health, Wellness and Goals
- 392.1K Introduce Yourself
- 43.6K Getting Started
- 259.9K Health and Weight Loss
- 175.7K Food and Nutrition
- 47.4K Recipes
- 232.3K Fitness and Exercise
- 403 Sleep, Mindfulness and Overall Wellness
- 6.4K Goal: Maintaining Weight
- 8.5K Goal: Gaining Weight and Body Building
- 152.8K Motivation and Support
- 7.9K Challenges
- 1.3K Debate Club
- 96.3K Chit-Chat
- 2.5K Fun and Games
- 3.4K MyFitnessPal Information
- 23 News and Announcements
- 998 Feature Suggestions and Ideas
- 2.4K MyFitnessPal Tech Support Questions