From: mazur@inmet.camb.inmet.com (Beth Mazur)
Subject: Re: Fitness thoughts
Organization: Intermetrics Inc, Cambridge MA
Date: Fri, 28 Aug 1992 14:33:59 GMT

In article <1992Aug27.063740.28895@edwards-vax.af.mil> becker@edwards-vax.af.mil writes:
>From: mazur@inmet.camb.inmet.com (Beth Mazur) writes...
>
Becker writes:
>>>>You do realize that for burning FAT you must find your target heart
>>>>rate and keep it at that rate for 20 minutes before your body begins
>>>>to burn fat?  
I respond:
>>The reason you didn't realize it is that it isn't true.  You are burning
>>fat the minute you start to exercise.  However, some of the other benefits
>
>hummm, there are those that would argue with that statement.

My reference is Covert Bailey, The New Fit or Fat, page 38.  What's yours?

	"Many people mistakenly believe that it takes twelve minutes
	 of aerobic exercise before fat is burned.  They think that their
	 muscles use glucose for twelve minutes and then start using fat. 
	 This is incorrect.  Fat is burned from the very start of the
	 exercise. The only time fat isn't used is when you're exercising
	 too hard for the fat-burning enzymes to function."
>
>>of cardiovascular improvement do take longer periods of exercise. 
>
>and what benefits are those?

Continuing from the previous quote:

	"The question is, if fat is burned from the very start of exercise,
	 what difference does it make how long we exercise? ... The answer
	 is that you are trying to produce *growth* of fat-burning
	 enzymes and a minimum of twelve minutes of continual, gentle
	 activity seems to be the time trigger necessary to stimulate 
	 this growth."
>
>>his PBS special, Covert Bailey talks about 12 minutes of x-country skiing,
>>15 minutes of jogging, and 40 minutes of walking as being what you should
>>aim for.
>
>hummm, and I suppose his word is the final word?
>
Well, there are those who would argue that his isn't the final word.  But
I take his word over yours.

>>As far as figuring out *your* target heart rate, the best way is to get
>>on a LifeStep and work up to a pace that you feel you could do for 20
>>minutes or so and that enables you to talk without gasping.  Now take 
>
>Now are you absolutely sure about that advise?  Too many people do 
>exactly what you just suggested and get NO fat reduction because its simply
>not happening.  

Geez, you mean you haven't heard that people burn more fat exercising at
a lower intensity?  When you start working out so hard that you are gasping,
or unable to breath comfortably, you are at the anaerobic threshold.
You are *not* burning fat if your muscle cells cannot get any oxygen.

>Everyone has their OWN theories.  Some seem fine, some are misleading.
>If you are not an expert, which none of us are, then you need to take
>what you've been reading and decide for yourself.  I'd go ask my doctor.

I agree.  The one true fact is that there are no universally accepted
truisms in the fitness arena.  Read up, ask for opinions (and try and
figure out where they got their advice), and don't do what doesn't feel
good to your body.

Beth Mazur                   "...life is more than a vision.  The sweetest
mazur@inmet.inmet.com         part is acting after making a decision."
...!uunet!inmet!mazur                                  -- The Indigo Girls
Newsgroups: misc.fitness