Monday, November 13, 2006


We're borrowing this from our friend, Alwyn Cosgroves blog at:

More and more evidence in support of High Intensity Interval Training.

The Afterburn Effect
Here's a study I looked at recently and mentioned at the last seminar I taught:
====Schuenke MD, Mikat RP, McBride JM.Effect of an acute period of resistance exercise on excess post-exercise oxygen consumption (EPOC): implications for body fat management.Eur J Appl Physiol 2002 Mar;86(5):411-7This group looked at the effects of circuit weight training on EPOC.The exercise routine consisted of three exercises (the bench press, the power clean and the squat), performed with 10RM loads as a circuit. The circuit was performed four times (i.e. twelve total sets) and took 31 mins.EPOC was elevated for 38 hours post workout (possibly longer as this was when the researchers stopped measuring). The duration and magnitude of the EPOC observed in this study indicates the importance of the role of high intensity resistance training in a fat loss program.====This type of information should go a long way in helping fitness professionals design and implement effective fat loss programs. It's not the workout - it's the effect of that workout on EPOC.I call this Afterburn - metabolic disturbance. Craig Ballantyne calls this Turbulence. but we're talking about the same thing - elevating EPOC to maximize caloric burn for the other 23+ hours per day. Is there much of a real world effect of burning 300 calories per workout (e.g. aerobic work) if I don't elevate EPOC?If we could elevate EPOC even an apparently insignificant 1/4 of a calorie per minute for the 38 hours that the study showed, then that 31 minute resistance training workout would burn X calories during the session plus an extra 570 calories over the next 38 hours. That becomes significant.In the past - fitness professionals and researchers have looked at how much fat is burned during the exercise session itself. This is extremely short-sighted.As my colleague Alan Aragon said:
"Caring how much fat is burned during training makes as much sense as caring how much muscle is built during training."Think about that. If we looked at a weight training session that started at 9am and finished at 10am - how much muscle would we see built if we stopped looking at 10am? None.In fact - we'd see muscle damage. We could make the conclusion that weight training does not increase muscle - in fact it decreases muscle right? It's only when we look at the big picture - and look at the recovery from the session - that we find the reverse is true - weight training builds muscle.Fat loss training is the same way. Someone talking about the benefits of the "fat burning zones" or "fasted cardio" is a sure sign that the individual has stopped looking at the end of the exercise session. They have come to the conclusion that fasted, lower intensity steady state exercise burns the most fat and made a massive leap of faith to suggest it is best for real world fat loss.Using that same logic these same people would suggest avoiding weight training if you want to grow muscle.Take home message - focus on the Afterburn effect not just what happens during the exercise session.--ACPS - My question is - could we get ANOTHER EPOC boost if we train less than 38 hours later? Could we raise an already elevated metabolism further? These are the questions that keep me up at night.


Mark Reifkind said...

great post jason, thanks. very interesting also speaks to making sure one gets enough anti oxidants!

Brian M said...

Hey Noticed that Kathy and Jason are on the main crossfit site. Hooyah to that.
One of three officers to pass my 1000 yd bayswim in fins. Max time was 22 mins in 59 degree water. Finished 20'58. The workout felt easy almost. Thanks guys for the great conditioning. Miss you all.
Happy Pt,
Brian M

Pamela MacElree said...

Hey Brian, Nice Work! Congrats! Where are all the training photos?? Stop in for a workout down memory lane next time you're home.