Thursday, December 30, 2010

Burning Fat

Because I have some (minimal) education as a personal trainer, and because I read research (a lot), I am often asked what burns more fat - intensity or duration.  It is not that simple of course, but the question for me is always, which burns more calories.  That thought is shared by some who are experts.


An even more complex question was posed in research from The Queensland University of Technology in Australia.  The scientists wanted to know which of two intensities was best for fat loss - the million dollar question.  Their study hardly offers a conclusion as it involved only 11 people, but it adds to the dialogue.

The obstacle is understanding the intensities themselves. If any reader can explain more than I, please do comment. 

The scientists compared an hours worth of activity at the level of maximum fat oxidation per individual vs 80% of a persons ventilatory threshold.  Ok.  There must be an intensity that one reaches where they are pulling fat from cells and turning it into free fatty acids, or oxidising it, and thus burning it.  The other, VT, is about breathing - but seems similar to maximum heart rate and perceived exertion etc.  It is far more technical and relates to expiration of carbon dioxide and oxygen, but lets just say it is the level where you are not comfortable talking - or on a scale of 1-10 with ten being the hardest effort you've got, you are doing an 8.

It seems that the fat oxidation effort would be harder - but that is a completely arbitrary statement on my part.

The researchers found that in the one hour session, the amount of fat that was burned was the same, BUT, the amount of overall calories was higher in the 80% VT group.  The researchers conclude that people should be told to exercise at the 80% ventilatory threshold.  If you are interested in learning more, Google away :)

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