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Stupid question about building muscle whilst in deficit

mrtoaster
mrtoaster Posts: 90 Member
edited January 2 in Health and Weight Loss
I often read posts with people stating you can’t build muscle whilst trying to lose weight, because you body needs a daily excess to build new muscle? Surely the fact that you are trying to lose weight means you have an excess of fat - which is your body’s energy reserve, I would have thought that the body would just use that to build muscle if needed. Does anyone know of the proper medical reason why this doesn’t happen.

Another common statement I see is people doing cardio and trying to lose weight will also result in your body burning muscle mass in addition to fat? I would assume that any cardio work requires you to use your muscles, so why would your body consume them, when it has all that lovely fat reserves?

For the record I do cardio and strength training about 5 times a week and am generally satisfied with my progress. It’s just seems that these two statements keep re-occurring on the message boards and they don’t make biological sense (in my head anyway)

Replies

  • Klopford
    Klopford Posts: 129
    Dunno bout the first part but addressing the second: This is why I don't worry about "starvation mode." That only happens when you've got no fat to burn. (I've got PLENTY!) :laugh:
  • seedawg23
    seedawg23 Posts: 52 Member
    Bump
  • SideSteel
    SideSteel Posts: 11,068 Member
    http://www.bodyrecomposition.com/fat-loss/adding-muscle-while-losing-fat-qa.html
  • nas061
    nas061 Posts: 256 Member
    I'm interested to know the full answer, but I can say that biochemically the body can't convert fat to muscle.
  • LeidaPrimal
    LeidaPrimal Posts: 198 Member
    The first statement is incorrect. There are two well-known exceptions to the 'can't gain in deficit' rule:
    -an overweight person
    -a beginner who did not exhaust linear gains
    (also genetic wonders of all kinds, and an over-weight beginner)

    For the second rule, there is a point at which your cardio starts working against you, normally it is when you get to the 'average' body fat, which is about 30-20% range for women and something like 10-20% for men (I am fuzzy on men's numbers). Once you try to go to the fitter levels of fat (sub-average), the body will start doing crazy things to conserve the layer of fat, resulting in the 'fat aerobic instructor phenomenon, when you start losing muscle, not fat. I want to emphasize that average body level fat % is quite rounded and if you look at a person with an average BF% you won't peg them for a regular gym person who trains hard (well, for women at least; men has that lower body fat + bigger muscle on the upper body).

    The reasons behind the both is that from the body's perspective fat is great, useful substance we want more of (to help us survive the upcoming starvation spell), while muscle is pretty useless beyond an average point, when you can do things okay, run, lift etc. So, it makes sense to start disintegrating muscle to conserve fat.

    Anyway, it may not matter that much to men if they don't mind some tummy left on them, but that dilemma is super-important to women, as they risk stripping their upper body to the concentration camp look, while still keeping rippling plushy thighs that makes them look 20 lbs heavier than they are.
  • 19bulldog60
    19bulldog60 Posts: 96 Member
    bump
  • jlbeals
    jlbeals Posts: 65 Member
    Not sure why it happens, but your body won't JUST burn fat if you've got a lot of extra fat - it'll burn muscle too. I lost 4 lbs in the past two weeks and according to my dietitian who I just got back from meeting with, half of that was muscle mass because I've been eating at what she considers too high of a deficit (I have MFP set to 1.5lbs/week so I'm not even going for the 1200 cal mark everyone else seems to be :P) Granted, her scale uses induction which isn't all that accurate, but I get measured with it every two weeks, so it's probably at least consistent.

    I should add that I'm currently on a strength/cardio workout program (Jillian Michael's Body Revolution without sticking to the ridiculous calorie restriction/eating plan per the dietitian's orders), and I average 1500-1600 cals/day, but I'm supposed to be hitting around 1800.
  • mrtoaster
    mrtoaster Posts: 90 Member
    I'm interested to know the full answer, but I can say that biochemically the body can't convert fat to muscle.

    I know the body can't turn fat into muscle, but the body breaks down fat to energy to sustain and repair itself, therefore why cant it use that to build some muscle or at the very least use your daily protein intake to do that?
  • danasings
    danasings Posts: 8,218 Member
    http://www.bodyrecomposition.com/fat-loss/adding-muscle-while-losing-fat-qa.html

    Not a stupid question at all. Please read the Lyle McDonald article shared by SideSteel, it will help you in your quest for knowledge.
  • AnvilHead
    AnvilHead Posts: 18,343 Member
    ...Another common statement I see is people doing cardio and trying to lose weight will also result in your body burning muscle mass in addition to fat? I would assume that any cardio work requires you to use your muscles, so why would your body consume them, when it has all that lovely fat reserves?...
    Read the results of this study, in which cardio-only participants lost a significant amount of lean body mass; subjects doing strength training lost less weight overall, but no LBM loss:

    http://www.ncbi.nlm.nih.gov/pubmed/10204826
This discussion has been closed.

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