HIIT on empty stomach

justinkimcentral
justinkimcentral Posts: 127 Member
in Health and Weight Loss
So theres numerous debates regarding this but both say that your body has no glycogen reserves so it uses fat or muscle. They said it uses muscle because something to do with glycogen. And hence they said to eat something before... but wiuldnt that make the cardio useless since you just use sugar at that point. And theres something called EPOC where if you dont eat or something you use fat as fuel?? And then comes HIRT, basically weight lifting on empty stomach, can we bring that in too? My main goal is to lose fat and maintain lean mass.

Replies

  • TavistockToad
    TavistockToad Posts: 35,719 Member
    in what situation does your body have 'no glycogen reserves'?
  • TavistockToad
    TavistockToad Posts: 35,719 Member
    justinkimcentral wrote: »
    TavistockToad wrote: »
    in what situation does your body have 'no glycogen reserves'?

    Empty stomach

    nope.
  • Running_and_Coffee
    Running_and_Coffee Posts: 811 Member
    Yes, I do frequently. I have a little more power in my workouts if I've had breakfast and particularly coffee, but about 50% of the time, I do things like sprint intervals and weights on an empty stomach, and it's totally fine.
  • sarahthes
    sarahthes Posts: 3,252 Member
    I thought the primary benefit of working out fasted was to improve fat oxidation for endurance sports?

    But that's a metabolic thing and has nothing to do with weight loss, and in any case my google fu failed me when I tried to look it up.

    Personally I only workout fasted when I work out in the mornings, and that's more to do with Synthroid timing than anything else.
  • californiagirl2012
    californiagirl2012 Posts: 2,625 Member
    justinkimcentral wrote: »
    So theres numerous debates regarding this but both say that your body has no glycogen reserves so it uses fat or muscle. They said it uses muscle because something to do with glycogen. And hence they said to eat something before... but wiuldnt that make the cardio useless since you just use sugar at that point. And theres something called EPOC where if you dont eat or something you use fat as fuel?? And then comes HIRT, basically weight lifting on empty stomach, can we bring that in too? My main goal is to lose fat and maintain lean mass.

    EPOC is more about oxygen consumed in the body which is important to metabolism.

    Your body will likely have enough glycogen stores in the muscle and liver before you exercise if your session in an hour or less even on an empty stomach, but really it depends on how much food energy you consumed the day before. You will feel the effects of depleting your glycogen stores after about an hour when your muscles will ache, that's typically a sign of glycogen being depleted.

    Since true HIIT can only be done for 30 minutes max, you can do it fasted or not, it's entirely personal preference and what matters more is the energy consumed the day before. The metabolism can convert any macro into glycogen storage.
  • AnvilHead
    AnvilHead Posts: 18,344 Member
    edited May 2018
    justinkimcentral wrote: »
    So theres numerous debates regarding this but both say that your body has no glycogen reserves so it uses fat or muscle....

    To start with, I'd ignore anything from anybody who believes the above. Because it's obvious they have no understanding whatsoever of physiology, so whatever else follows will be equally useless.

    If your goal is to preserve lean mass, eat at a reasonable caloric deficit, get adequate protein intake and engage in a well designed strength training program. All of that other stuff is either garbage, or majoring in the minors to the extreme.
  • AnnPT77
    AnnPT77 Posts: 31,935 Member
    AnvilHead wrote: »
    justinkimcentral wrote: »
    So theres numerous debates regarding this but both say that your body has no glycogen reserves so it uses fat or muscle....

    To start with, I'd ignore anything from anybody who believes the above. Because it's obvious they have no understanding whatsoever of physiology, so whatever else follows will be equally useless.

    If your goal is to preserve lean mass, eat at a reasonable caloric deficit, get adequate protein intake and engage in a well designed strength training program. All of that other stuff is either garbage, or majoring in the minors to the extreme.

    Totally this ^^^^, all day long.

    Personally, I don't work out fasted for anything of more than mild intensity that exceeds 10 minutes. Why? Because my performance s*cks if I do. This is not true for everyone.

    Unless you're an actual elite athlete working on squeezing out the last fractional percent of performance, timing of eating matters not at all, except insofar as it makes you feel better/worse, or perform better/worse during the workout, all of which is individual and subjective.
  • stanmann571
    stanmann571 Posts: 5,728 Member
    edited May 2018
    AnnPT77 wrote: »
    AnvilHead wrote: »
    justinkimcentral wrote: »
    So theres numerous debates regarding this but both say that your body has no glycogen reserves so it uses fat or muscle....

    To start with, I'd ignore anything from anybody who believes the above. Because it's obvious they have no understanding whatsoever of physiology, so whatever else follows will be equally useless.

    If your goal is to preserve lean mass, eat at a reasonable caloric deficit, get adequate protein intake and engage in a well designed strength training program. All of that other stuff is either garbage, or majoring in the minors to the extreme.

    Totally this ^^^^, all day long.

    Personally, I don't work out fasted for anything of more than mild intensity that exceeds 10 minutes. Why? Because my performance s*cks if I do. This is not true for everyone.

    Unless you're an actual elite athlete working on squeezing out the last fractional percent of performance, timing of eating matters not at all, except insofar as it makes you feel better/worse, or perform better/worse during the workout, all of which is individual and subjective.

    LOL,

    Personally, I don't eat more than a bite or two before working out at anything more than mild intensity. Why? Because my performance s*cks if I do. This is not true for everyone.

    Totally agree with the above, just wanted to share my entirely opposite n=1.

    Bottom line is you gotta do you, and you will make mistakes figuring it out.

    So,

    Try morning, try afternoon, try evening

    Try fasted, try a light snack(Half PB sandwich if you're not allergic), try after a decent sized meal.

    You'll figure out what works for you. You'll also figure out what's second best and what's a non-starter. For me. Fasted First thing in the morning is best. Sometimes I can't so Second best is right after work with at least 3 hours since I ate. After dinner is right out. I get loggy, and then I can't sleep. So double whammy
  • tbright1965
    tbright1965 Posts: 852 Member
    The human body keep 300-700g of glycogen stored, depending on size. That's about 1200 to 2800 calories of easy to get to energy stored.

    Unless you haven't eaten in 24 hours, or are hours into a race, you probably are no where near having depleted your glycogen stores.
  • tess5036
    tess5036 Posts: 942 Member
    I exercise fasted, but mainly because that is how I am most comfortable, I feel sluggish and slow and can't exert as much effort if I have eaten. Even on a marathon I'll only eat light carbs two hours before. Do what works for you.
  • sijomial
    sijomial Posts: 19,811 Member
    justinkimcentral wrote: »
    AnvilHead wrote: »
    justinkimcentral wrote: »
    So theres numerous debates regarding this but both say that your body has no glycogen reserves so it uses fat or muscle....

    To start with, I'd ignore anything from anybody who believes the above. Because it's obvious they have no understanding whatsoever of physiology, so whatever else follows will be equally useless.

    If your goal is to preserve lean mass, eat at a reasonable caloric deficit, get adequate protein intake and engage in a well designed strength training program. All of that other stuff is either garbage, or majoring in the minors to the extreme.

    So how would i input cardio but still maintain lean muscle mass and lose fat since cardio is beneficial for the heart and also health and also a few more calories hehehe

    Exercise doesn't burn muscle for fuel - otherwise the more people trained the less muscle they would have!

    You are waaaaaaaaaaaaaay over thinking this.

    Keep it simple.
    Exercise for fitness, health, strength (and enjoyment hopefully!).
    Calorie deficit to lose fat.
  • Pastaprincess1978
    Pastaprincess1978 Posts: 371 Member

    Keep it simple.
    Exercise for fitness, health, strength (and enjoyment hopefully!).
    Calorie deficit to lose fat.[/quote]

    I don't want to hijack - but thanks for this comment. It sums up why eating less is so important for the majority of non-fit people who want to lose weight (like me!).

    So simple, so difficult when you are breaking habits.

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