Why do we lose muscle?

[fade2green514]

Ok I understand the science of burning fat, but im confused as to why one loses muscle? What processes are going on that make muscle loss occur? I'm getting enough protein fat and carbs and my lifts are staying the same, but a few years ago I lost a bunch of muscle due to lack of calories even though my macros were OK why is this?

My first guess is that due to less capillary surface area, your body cannot metabolize the fat as quickly and chooses muscle in its place, without proper diet and calories.

[take3]

Ok I understand the science of burning fat, but im confused as to why one loses muscle? What processes are going on that make muscle loss occur? I'm getting enough protein fat and carbs and my lifts are staying the same, but a few years ago I lost a bunch of muscle due to lack of calories even though my macros were OK why is this?

My first guess is that due to less capillary surface area, your body cannot metabolize the fat as quickly and chooses muscle in its place, without proper diet and calories.

your muscle requires calories to maintain... you are in a state of calorie shortage..think about it.

analogy: X costs 150 bucks a month, you're on a tight budget..

[fade2green514]

your muscle requires calories to maintain... you are in a state of calorie shortage..think about it.

analogy: X costs 150 bucks a month, you're on a tight budget..

but if you have the body fat (calories) for it then why does the muscle break down?

[take3]

your body can't take out a loan, what it has on it (fat stores) is what it has... go too low in BF and you die..the heart is supported by fat as a holster, if you will.

if you're losing 100 bucks a month, you have 1000 in the bank, loans are not an option, bankruptcy is death, do you cut spending or just eat through your savings?

[Damodred]

your body can't take out a loan, what it has on it (fat stores) is what it has... go too low in BF and you die..the heart is supported by fat as a holster, if you will.

if you're losing 100 bucks a month, you have 1000 in the bank, loans are not an option, bankruptcy is death, do you cut spending or just eat through your savings?


If only there was a like button on these forums :P .. instead.. repped :D

[Emma-Leigh]

but if you have the body fat (calories) for it then why does the muscle break down?

Main few reasons -
1/ there is a limit at which fat can be released from fat cells - this 'caps' the rate of energy that can be generated. So if this fat-release is not enough to cover the deficit created through diet and exercise, then extra energy will be liberated from somewhere - aka: lean tissue.

The LEANER you are, the lower your fat mass. And the lower your fat mass, the smaller tje amount of energy generated, and the smaller the deficit successfully covered (which is why you can / should only create small deficits when you are lean - otherwise you lose too much lean mass).

2/ the body has obligate requirements for a few things - amino acids being one of them. If your diet intake fails to adequately meet the needs of your amino acids, it degrades lean mass to make up the difference.

3/ fat mass is lousy at making glucose <-- thus if you need glucose for a reason (eg: high intensity exercise) if glucose intake is inadequate via the diet, you are more likely to draw on lean mass to cover the need.

[f4k]

My anatomy and physiology book says basically what was said already, but in my own words:

A body has a [daily/hourly/minutely/secondly] requirement for amino acids; these are used to build everything from white blood cells to skin tissues. everything is constantly being replaced by mitosis, and generally most active mitosis occurs during sleep.

Where does the body get amino acids? initially, from the blood stream. you have a constant circulating population of amino acids. When the blood concentration of amino acids begins to fall, where THEN does it come from? Well hopefully, from your DIET. Because if you are not EATING the amino acids, they must be taken from somewhere else... namely, from inside your body. That is, any tissue containing amino acids is generally susceptible to being torn down to meet the circulating blood requirements.

So simply enough, the body can and will just rip apart your muscle tissue to feed its amino acid requirements, if you are not eating enough of them.

Glucose requirements complicate matters greatly. Muscle fiber can be torn apart to feed amino acid requirements... AND it can be torn apart to make glucose. As was mentioned, triglycerides are poor replacements for plain glucose, and the brains primary source of nutrition is glucose, so as blood glucose concentrations fall and bodyfat becomes very limited (as on a "cut") the requirements for glucose may also be met by amino acids (a process called gluconeogenesis iirc?) So you can lose muscle by not eating enough amino acids, AND by not properly adjusting your "end of cut" glucose requirements. too much in the blood and you build back fat storages, too little and you may lose muscle.

Now its my turn for a question:
there is an enzyme responsible for this activity... Why hasnt anyone developed an inhibitor? I mean, we have PDE-5 inhibitors to maintain erections... why not inhibit muscle tissue breakdown enzymes? iirc its called "capsin" or something along those lines, the book identified it. When I get to medical school I will ask the instructor :D

[msm00b]

Muscle loss comes from one of two things:

1) Inadequate exogenous amino acids- IE your diet sucks
2) Inadequate training (atrophy)

If you're eating enough protein and training consistently, you realistically aren't going to be losing muscle. Most of the posters here are stupidly afraid of muscle loss - it's rarely an issue if you're doing it right.

[fade2green514]

ok so, you need x amount of essential dietary fats, y amount of dietary carbohydrates (glucose, or glycogen/whatever) and z amount of amino acids (protein)...

is there a way to get exact amounts of exactly what you need to increase your total possible weight loss?

and do cortisol controller supplements work well to help keep muscle from breaking down or will healthier foods in general be enough?