Re: Half marathon, low carb, ignorant questions

Discussion in 'General Fitness' started by Lyndon, Sep 16, 2004.

  1. Lyndon

    Lyndon Guest

    ignoramus26859 wrote:

    >In article <[email protected]_s53>, Bear G wrote:
    >> Donovan Rebbechi wrote:
    >>>>Is it possible to do on a low carb diet, given that I am in a reasonable
    >>>>average condition?

    >>
    >> The problem is muscle glycogen levels. I can't remember if I saw
    >> the link here or in a *Fit forum but there's a paper out that
    >> compares muscle glycogen levels in three groups. As I recall:
    >>
    >> carboloaded runners: 60-70 (mg/g?)
    >> average diet runners: 35-40
    >> low-carb diet: 15
    >>
    >> You need muscle glycogen to burn fat, and you can't refresh it
    >> fast enough by eating energy gels. (That doesn't mean they're
    >> worthless, just not enough to allow you to run indefinitely.)
    >> Once your muscle glycogen is exhausted you bonk.

    >
    >That would be for anaerobic workouts, no?
    >

    For aerobic OR anaerobic workouts, the primary source of energy is glycogen,
    which is what you deny yourself on a low carb diet.

    >For aerobic workouts, glucose is supplied to muscles continuously, as
    >are fatty acids. Am I mistaken?
    >

    Part of the glycogen is stored in the muscle tissue and part comes from the
    bloodstream. For longer (over 30 minutes) aerobic activity, part of the energy
    comes from fat from the bloodstream. If your glycogen stores are reduced due
    to poor diet (i.e. low carb), then much more of the energy you consume during
    exercise must come from fat sources, or you will hit the wall. The speed you
    can run off primarily fat is MUCH slower than the speed you can run off mostly
    glycogen.

    >Thanks. My purpose really is to find how far can I go while being on
    >an LC diet... So, quite possibly, I would achieve suboptimal results
    >(time to run the half marathon) while on LC, however, it would be
    >actually a more interesting experiment to me. "can I run half marathon
    >on LC"
    >

    It is not necessarily during a single long run where the effects of the
    low-carb diet is seen. If you run a single long run VERY slowly, you can
    likely do this for 1-2 hours, consuming enough fat to keep your diminished
    glycogen stores from striking zero. But there ia acatche here:

    Dr. David Costil, in his book, "Inside Running: The Basics of Sports
    Physiology" (page 63) has a chart showing the difference on glycogen stores
    from a low versus high carb diet while training everyday. You need 6-10 g/kg
    of carbs every day to keep your glycogen stores up. If you get much less than
    this--and you can't recover the carbs you expended in your last workout from
    your diet before your next workout--your glycogen stores will gradually decline
    EVERY DAY until you finally bonk. It isn't necessarily any one training
    session that will kill you; It is the cumulative effect of a training program.

    Lyndon


    "Speed Kills...It kills those that don't have it!" --US Olympic Track Coach
    Brooks Johnson
     
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  2. np426z

    np426z Guest

    "Lyndon" <[email protected]> wrote in message
    news:[email protected]

    > Dr. David Costil, in his book, "Inside Running: The Basics of Sports
    > Physiology" (page 63) has a chart showing the difference on glycogen

    stores
    > from a low versus high carb diet while training everyday. You need 6-10

    g/kg
    > of carbs every day to keep your glycogen stores up. If you get much less

    than
    > this--and you can't recover the carbs you expended in your last workout

    from
    > your diet before your next workout--your glycogen stores will gradually

    decline
    > EVERY DAY until you finally bonk. It isn't necessarily any one training
    > session that will kill you; It is the cumulative effect of a training

    program.
    >
    > Lyndon


    You haven't done much cell biology have you, 'Big L'? I think a refresher
    course is in order.
     
  3. On 2004-09-16, Ignoramus26859 <[email protected]> wrote:
    >> For aerobic OR anaerobic workouts, the primary source of energy is glycogen,
    >> which is what you deny yourself on a low carb diet.

    >
    > Glycogen, but not muscle glycogen, right?


    Yes muscle glycogen. Liver glycogen is mostly for the brain IIRC.

    Cheers,
    --
    Donovan Rebbechi
    http://pegasus.rutgers.edu/~elflord/
     
  4. Doug Freese

    Doug Freese Guest

    "np426z" <[email protected]> wrote in message
    news:[email protected]
    > "Lyndon" <[email protected]> wrote in message
    > news:[email protected]
    >
    >> Dr. David Costil, in his book, "Inside Running: The Basics of Sports
    >> Physiology" (page 63) has a chart showing the difference on glycogen

    > stores
    >> from a low versus high carb diet while training everyday. You need
    >> 6-10

    > g/kg
    >> of carbs every day to keep your glycogen stores up. If you get much
    >> less

    > than
    >> this--and you can't recover the carbs you expended in your last
    >> workout

    > from
    >> your diet before your next workout--your glycogen stores will
    >> gradually

    > decline
    >> EVERY DAY until you finally bonk. It isn't necessarily any one
    >> training
    >> session that will kill you; It is the cumulative effect of a training

    > program.
    >>
    >> Lyndon

    >
    > You haven't done much cell biology have you, 'Big L'? I think a
    > refresher
    > course is in order.


    Lyndon's cite matchs the latest science that I have read. Why don't you
    educate us Roger!

    -DougF
     
  5. Barf Bag

    Barf Bag Guest

    >You haven't done much cell biology have you, 'Big L'? I think a refresher
    >course is in order.


    They banned him after that "public masturbation" incident.
     
  6. Barf Bag

    Barf Bag Guest

    >Liver glycogen is mostly for the brain

    Ah, now I understand your problem.
     
  7. Sam

    Sam Guest

    "Donovan Rebbechi" <[email protected]> wrote in message
    news:[email protected]
    > On 2004-09-16, Ignoramus26859 <[email protected]> wrote:
    > >> For aerobic OR anaerobic workouts, the primary source of energy is

    glycogen,
    > >> which is what you deny yourself on a low carb diet.

    > >
    > > Glycogen, but not muscle glycogen, right?

    >
    > Yes muscle glycogen. Liver glycogen is mostly for the brain IIRC.
    >
    > Cheers,
    > --
    > Donovan Rebbechi
    > http://pegasus.rutgers.edu/~elflord/


    Correct. The liver also supplies glucose for the blood as well.
     
  8. np426z

    np426z Guest

    "Doug Freese" <[email protected]> wrote in message
    news:[email protected]

    > > You haven't done much cell biology have you, 'Big L'? I think a
    > > refresher
    > > course is in order.


    > Lyndon's cite matchs the latest science that I have read. Why don't you
    > educate us Roger!


    For free? <splutter>

    I had (have) to pay for my education. May I suggest we apply this
    principle to Usenet as well?
     
  9. Doug Freese

    Doug Freese Guest

    "np426z" <[email protected]> wrote in message
    news:[email protected]
    > For free? <splutter>
    >
    > I had (have) to pay for my education. May I suggest we apply this
    > principle to Usenet as well?


    Selfish side step if not total avoidance.

    -DF
     
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