The myth about "burning muscle"

wow thanks goldie cleared things thing up
+KARMA 

Just a side note on "burning" proteins;

 - Remember all muscles in your body are slowly being broken down. Irrevocable fact - this has nothing to do with starvation or similar, more a case of efficiency as skeletal muscle requires such a high energy input to maintain your body is always looking for an excuse to get rid of it. Before any of you panic, remember that you use nearly all the muscles in your body every day just doing normal activities. I am talking about complete inactivity here (which is why people with serious knee/ankle surgery who literally cannot use certain leg muscles for a month or two afterwards lose inches from inactivity. However, this also means the bigger you get, the slightly more stimulus you require to maintain that muscle.

 - Free amino acids (circulating in the blood) are respired at their highest rate relatively early on - around the same time as fats start to be respired at their highest proportion or slightly before. But even then, like glycogen and glucose although rates fall below normal (basal) levels, they are not completely used up by any means.

 - Exercise intensity speeds up the 'starvation' response -  little obvious as of course energy resources are depleted faster! "In many respects the overall metabolic response to prolonged exercise is strikingly similar to that observed after 3 days of starvation." (although this is refering to 4hrs of continuous mild-moderate intensity exercise) G Ahlborg et al. (1974) Substrate Turnover during Prolonged Exercise in Man, J Clin Invest. 53, pp1080-1090

Although protein is metabolised - unless you're in the habit of frequently running marathons - you aren't going to significantly effect muscle catabolism by doing cardio - especially not if you're following Scooby's 3-4hr meal advice!

1 - This is much more gradual. Read my very first point in my previous post.
2 - same as above! However bear in mind that if you mess with ANY metabolic system, especially with such a universally-accepted mediator such as a steroid (which has different effects on a number of cell types), then you'll be screwing with the balance of a number of other completely unrelated systems too (ranging from blood pressure, Ca uptake, bone growth, etc. etc.).

The post above me is true only if you lose fat too much and too fast. Your body is smart and if it detects signs of starvation it will simply slow down your metabolism and lower your performance, because if you'd be starving and still maintain your huge performance it would lead to imminent death more quickly.

As to what Goldie wrote, it's a nice post, but I want to add that protein is not the last that is broken down when in starvation mode. The body will break down protein along with fat.

It won't be in stages, fat, and protein last because in order to break down protein in requires energy, so if there is no fat left it can't break that protein. This is how rabbit starvation works, but also Fatkins diet.
So it's mixed breakdown.

As Uglok said your body goes through catabolic stages all the time, the main reason not worry about this is that it simply has some sort of border where it takes and puts constantly. This is defined strictly because you'll never see your body going to extremes in one day. So it has it's small margins where it can take and put back. Through exercise you gain muscle let's say, since you've created a demand, that border will go up on top the new gains.

I heard of another myth of burning your muscle..
which is basically that supposibly if you workout too hard for example chest u might burn ur muscle and you will not be able to gain muscle.
Find this not true but Ive heard it alot what u guys think???

Sorry, but I don't really agree with this. If cardio doesn't burn muscle than why don't we see guys walking around with zero percent body fat?

goldie i will really appreciate it if you can post the sources where you get all those informations. .
Thanks a lot! I just want to see the credibility of the source

oh thanks. WebMD and the institute of health is a reliable source imo because i use that on some of my thesis paper. ty goldie