Burn fat not muscle?

I am wondering the same thing.  I have lost at least 25lbs now but still have a msall gut...would like to get rid of that and go for something more like a runner (2372) in this pic (and this is a chic!)

You are not "burning" muscle.  To have your body scavenge muscle proteins to convert it to use as glycogen for fuel, you have to have SERIOUSLY depleted your body.  And that is well into the proverbial "bonk" range.

The training you are talking about it simply using your aerobic mechanisms and keeping your HR below your lactic threshold and using glycogen and fat stores to provide the main fuel sources.  It is nothing more complicated than slowing down in your normal day to day training.

You cannot "train" your body to use different fuel sources.  When it boils down to it, it is pretty simple.  Your muscles run off of glycogen.  The primary source for this is carbohydrates that provide glycogen in its purest form for ease of use.  Every adult person can store around 1,500 - 2,000 calories in glycogen in their body for use.  The fat in your body can be converted to glycogen in the liver.  But it is a much slower process.  Your body is going to go for the easy stuff first (glycogen stores) while still pulling in some of the fat stores.  As you go harder, the need for fuel rapidly increases and it is going to go for the easiest/fastest thing it can get, which is again your glycogen stores.

Only in extreme cases where you have fully depleted your glycogen (marathons, half and full ironmans) and you continue to push your body will you unlock the "last ditch" effort of the body which is to start scavenging muscle to send to the liver to convert to glycogen.  This is an even LONGER process than trying to convert the fat over and has serious repercussions.  If you are this far into the fueling process, you are in a world of hurt.

OTOH, Yes endurance sports tend to make you leaner as the training adaptations are focus to improve/maximize performance on slowtwitch fibers. For those who are musclely will lose muscle mas due to trainning due to the opposite adapations of endurance vs strenght training which mainly adapts fasttwitch muscle fibers (and make them bigger). If your main goals is to lose weight and keep your muscle build, then do some running, biking, swiming, etc., add weight/strenght lifting to your training and keep an eye on your diet.

First of all a little basic biochemistry is in need:

Your cells us sugars as energy for movement, life, etc.  The easiest way for the cells to get sugar is to use the sugar in your blood.  When your body runs low on sugar, it will break down your fat cells to make sugar for energy.  When your fat supplies run low, your body will then break down your muscles for energy.  This would indication severe malnutrition, which is a sign of insufficient calorie intake.  If you are truly burning muscle to fuel your workouts, you need to see a nutritionist immediately.

Second genetics.

Genetics control many aspects of our appearance.  I could do aerobic for six hours every day, and my legs would never be stems.  They will always be tree trunks.  The same reason that my hair is brown, and my eyes green.  I'm sure that some of other 10 ladies in that picture would be displaying their midsections if they had definition like 2372.  (Look at 18?5, she doesnt have nearly the definition of 2372).  I wouldn't guess that they work any less hard than 2372, or have worse nutritional habits.

Third historical weight:

I would guess that 2372 hasn't had a lot of time at my top body fat content of 32% and body weight of 237.  My guess is that she has always been lean <10%, and this kept her from having the "extra skin" that I have, and most other "normal" people have.  Without lipo and surgery, I'm afraid that a six pack is NOT in my future.

What is in my future is 12-14% body fat (right now I am around 18%), improved cardiovascular health, and a longer, healthier life.

What Rick and Jorge said.

The 'chick' in question is Zivile Balciunaite. The 'other one' is Paul Radcliffe (world record holder, so maybe a 6-pack ain't everything, though Balciunaite beat her on this day).

EDIT:  Of course -- Paula, not Paul!

Thanks everyone for setting me straight... I primarily hear about this incorrect assumption from those who are avid weightlifters (like I was in my pre-tri days). There's this perception that you want to do some cardio, but not too much because you start to burn off everything you've trained for.

Yes... I was in denial for a while but have now come to terms with this (mostly) . I've decided I'd rather be thinner and in better overall shape, instead of muscular and unable to walk a flight of stairs without being winded.

Holy crap...has that been air brushed

I'm almost on the same boat as you.  I'm working with a sports nutritionist with my "diet" to loose 10 pounds (I'm currently 170, 17% fat).  She want to get me to 13% and loose all that pounds from fat and not muscles. 

I've been only running from September until late November.

So, she basically want me to include some "strength" workouts between my regular training, eg. abs, squats, pushups, dumbells (little weight), etc...  2-3X per week.

Apparently the theory is that if you do some kind of strength training the body will not loose the weight from muscles and will burn only fat....

That's the kicker... I've finally come to realize that I really must choose what's more important personally. Do I want to improve my overall tri times, or do I want to try and hang on to muscle for vanity sake. Now that I'm 37 with a wife and 3 kids (and of course much wiser ), my focus has become more about improving my times.

When you overload the muscles, via weight lifting, they will rapidly adapt and grow.

As I understand it, there is couple of consequences of this:-

1. Initially, you'll be heavier, the growth has come from muscles - so your body fat as an overall percentage will have declined.

2. Muscles always burn calories, it's always active. Fat is inert. If you can maintain your new muscle mass, without upping your intake of calories - then you'll also end up losing fat.

Training your body to burn fat is easy. Go long and slow....

Matt Cazalas
Technical Writer

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