The myth about "burning muscle"

I'm guessing what the answer above says about protein being the last source of energy means that you can do cardio and weights on the same days, eat high protein and low carb diet and therefore build muscle and lose fat at the same time?

To a degree, it's very true your body can't digest a huge amount of protein, I remember seeing 50g as the top number in one sitting but not entirely sure on that.

Your body needs protein throughout the day but if your doing nothing and haven't done for days then the need for protein diminishes rather significantly. Also to go into those states would takes days-weeks of not eating protein as far as I'm aware therefore I wouldn't see it as a huge worry, plus unless your on a vegetarian/vegan diet it's very unlikely you wouldn't get enough protein just from your average random food consumption.

The 6 meals is by no means set in stone, in fact the more meals the better really but obviously the more you eat the less time you have to do anything else.

No not if your fit and healthy. If your body fat is unhealthy low then it is possible that you'll maintain that last slither of fat and burn muscle, but we're talking really unhealthy now, like when you've been basically starving yourself for weeks. So realistically no it's not possible.

It's easy to see how people think cardio "burns muscle." It's an illusion created by glycogen depletion.  As described by Goldie, if you suddenly change from caloric maintenance to calorie deficit, the first thing to go is muscle glycogen, and that creates the "shrinking muscles" effect.

A great experiment that anyone (well-conditioned individuals with a clean bill of health only!!!) can do illustrates this beautifully.  First, eat exactly 500 calories above your maintenance level for a week by reducing cardio or eating more, and get most of your calories from healthy starchy carbohydrates like oats, potatoes, whole wheat, veggies, and fruit.  At the end of this phase take a picture of yourself in the mirror in your favorite pose, and weigh yourself.  Now, for 4 days, reduce your calorie intake to 1,000 below whatever your maintenance level is through both diet and adding in lots of medium-intensity cardio like running and biking.  Whatever you do for these four days, you must burn 1,000 or more calories below maintenance - you will start to feel real bad on day 2-3 if this works, similar to Scooby's carb cycling diet, except protein intake isn't as much of a concern here.  After this phase, on the 5th day take a picture again of yourself in the morning in the exact same pose as before, and weigh yourself.  You should be 10 pounds lighter and appear a bit deflated in the mirror - zero glycogen! It looks like you have lost muscle, but in reality it's just total glycogen depletion.  For those of you who do a ridiculous amount of cardio and therefore store way more glycogen than the average bodybuilder, you can lose as much as 10 pounds doing this experiment - all of it coming from glycogen stored in the muscles.  Most people who don't do cardio or limit themselves to an hour or two a week will lose at least 5 pounds.  It's easy to see where the 'cardio burns muscle' myth comes from!  The illusion of 15% of your muscle mass disappearing in five days is pretty dramatic.  Go ahead and add in another "refeed" week afterwards, and you'll find that you look the same in the mirror as you did before after another week, and your muscles blow up to their original pre-experiment size - no loss of tissue or mass!  For those of you doing Scooby's carb cycling diet, similar size changes will occur over each 3-day depletion cycle.

This is one of the reasons a lot of natural bodybuilders start adding in starchy carbs a few days before the show - rebuilding glycogen fills out your muscles and helps increase vascularity, as long as you don't overdo it and pig out.

If you're doing cardio for a longer than recommended your body WILL start burning protein If you do 10 hours of cardio (just a random example) you won't only lose fat because you've got 20% BF , you will lose fat AND muscle tissue

yea i never new the order of things when it came to that so i was afraid if i didnt eat soon enough i would be burning muscle or something. it turns out im just a chubster that snacks too much ahaha

Insteresting, this even sheds some light on how carb cycling works