Opinions and results on fasted cardio?

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Replies

  • PeachyCarol
    PeachyCarol Posts: 8,029 Member
    I went to the gym once in the afternoon instead of the morning, and I'd had my fast-breaking protein bar and tea about 2 hours before I went (I phrased it like that because I IF).

    I had the crappiest workout ever because I had to slow everything down because I was so nauseated.

    Never again.

    It's very interesting how different everyone is.
  • SergeantSausage
    SergeantSausage Posts: 1,673 Member
    85kurtz wrote: »
    SergeantSausage wrote: »
    Nothing turns a workout to shite like being Bonked before you even start, right?

    Pre-Bonked, fat, and stupid is no way to make a successful workout, right?

    This comment made me laugh out loud. I wonder if you should explain for those not familiar with the vernacular? LOL

    Bonk

  • ninerbuff
    ninerbuff Posts: 49,040 Member
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    My opinion is that if you're burning 400-700 calories from a run, and not eating, it's a pretty dumb idea to do.
    In your opinion why is it dumb? If you have 400-700 calories of stored glycogen in your system to do it, what is it affecting?

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...
    They didn't use it up sleeping. Fat is the primary source of energy at rest.

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

  • llUndecidedll
    llUndecidedll Posts: 724 Member
    I always feel like crap when doing fasted cardio. It just feels like I just can't rev my engine up, so I've started consuming caffeine before any exercise and it definitely helps. I don't understand why I feel like I have no energy, especially knowing I consumed enough calories the day before. Maybe it's more mental, than anything else.

  • bendyourkneekatie
    bendyourkneekatie Posts: 696 Member
    I was doing this for a while, when I wanted to free up my evenings and get a workout in before work. Then I started getting migraine symptoms while travelling to work: going completely blind on a packed train is not fun. After it happened a few times, I switched back to evening workouts and it never happened again (well, until I started commuting while pregnant and, yet again, going blind on packed trains...)

    It's interesting how this really seems to be one of those things that confirms there is no one size fits all for fitness or diet. You gotta learn your body and what works for it.
  • FunkyTobias
    FunkyTobias Posts: 1,776 Member
    edited May 2015
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    My opinion is that if you're burning 400-700 calories from a run, and not eating, it's a pretty dumb idea to do.
    In your opinion why is it dumb? If you have 400-700 calories of stored glycogen in your system to do it, what is it affecting?

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...

    Maybe instead of guessing, you actually do some research.

    32se_Main.jpg

    http://www.humankinetics.com/excerpts/excerpts/the-bodyrsquos-fuel-sources

  • charlieandcarol
    charlieandcarol Posts: 302 Member
    If I eat less than 2 hours before I exercise or run I get horrible indigestion, a stitch, have a rubbish run and often can't finish the run.
  • TimothyFish
    TimothyFish Posts: 4,925 Member
    I used to do it all the time. I would ride the Trinity Trail from 183 to the other side of downtown and back before breakfast. About 20 miles, if I recall. It did nothing for weight loss, and I didn't need to lose weight, but I didn't want to ride right after eating a meal. The body stories about 1600 calories worth of glycogen, so it should take more than one hour of cardio before any problems are even possible from depletion. At the ninety minute mark, people begin to have problems and could experience it sooner if other activities also used reduced the glycogen. So, if you do fasted cardio, just remember there are limits.
  • sijomial
    sijomial Posts: 19,809 Member
    Fasted or fed makes very little difference to me in terms of how I feel or to my performance. Recently set a PB for quite a hard 2 hour cycle when fasted.
    I'm quite adapted to it though as I do a form of intermittent fasting. So really both food and exercise fit in the day where convenient.

    Rides over two hours I would fuel, either before or during the ride (or both for very long rides).
  • icck
    icck Posts: 197 Member
    Really interesting read, thanks for posting this. :)

    Personally I need to eat *something* first thing after getting up, even just something small, else I start to feel nauseous and dizzy within the hour. I am an early morning gym goer and actually often eat on the walk there, with no ill effect.
    That said, I forgot to eat the other week and got a new running PB as a result. I felt unusually tired afterwards though and utterly ravenous, and ended up wasting money on the gym vending machines. I would be open to trying fasted cardio again, but would definitely take something with me to eat after or even during.
  • coreyreichle
    coreyreichle Posts: 1,031 Member
    ninerbuff wrote: »
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    My opinion is that if you're burning 400-700 calories from a run, and not eating, it's a pretty dumb idea to do.
    In your opinion why is it dumb? If you have 400-700 calories of stored glycogen in your system to do it, what is it affecting?

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...
    They didn't use it up sleeping. Fat is the primary source of energy at rest.

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm sure they didn't. But, given that most people eat dinner at 5PM, are awake until at least 9PM, and wake around 6AM to go and work out, I'm going to hazard after 13 hours of no caloric intake, their glycogen stores are NOT at 2000 kcals.
  • coreyreichle
    coreyreichle Posts: 1,031 Member
    FunkyTobias wrote: »
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    My opinion is that if you're burning 400-700 calories from a run, and not eating, it's a pretty dumb idea to do.
    In your opinion why is it dumb? If you have 400-700 calories of stored glycogen in your system to do it, what is it affecting?

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...

    Maybe instead of guessing, you actually do some research.

    32se_Main.jpg

    http://www.humankinetics.com/excerpts/excerpts/the-bodyrsquos-fuel-sources

    You do realize that table is an estimation of averages over a 24 hour period, right? And, that not all of those stores are available for immediate use? For example, if you're burning muscle protein, you're doing it wrong? And adipose isn't available until about 45 minutes in.
  • bmele0
    bmele0 Posts: 282 Member
    I get dizzy, light-headed, and faint if I don't eat something before :dizzy: . On the other hand, I can't go jog immediately after eating either, I have to wait an hour + depending on what I ate. So I basically have to plan :lol:
  • FunkyTobias
    FunkyTobias Posts: 1,776 Member
    coreyreichle wrote: »
    FunkyTobias wrote: »
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    My opinion is that if you're burning 400-700 calories from a run, and not eating, it's a pretty dumb idea to do.
    In your opinion why is it dumb? If you have 400-700 calories of stored glycogen in your system to do it, what is it affecting?

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...

    Maybe instead of guessing, you actually do some research.

    32se_Main.jpg

    http://www.humankinetics.com/excerpts/excerpts/the-bodyrsquos-fuel-sources

    You do realize that table is an estimation of averages over a 24 hour period, right? And, that not all of those stores are available for immediate use? For example, if you're burning muscle protein, you're doing it wrong? And adipose isn't available until about 45 minutes in.


    LOL. Can you read?

    Liver Glycogen ALONE is 400 cals, not to mention the 1500 calories of muscle glycogen. And as ninerbuff mentioned, you are not consuming this at rest.

    You should really quit when you're behind.

  • FunkyTobias
    FunkyTobias Posts: 1,776 Member
    edited May 2015
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    My opinion is that if you're burning 400-700 calories from a run, and not eating, it's a pretty dumb idea to do.
    In your opinion why is it dumb? If you have 400-700 calories of stored glycogen in your system to do it, what is it affecting?

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...
    They didn't use it up sleeping. Fat is the primary source of energy at rest.

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm sure they didn't. But, given that most people eat dinner at 5PM, are awake until at least 9PM, and wake around 6AM to go and work out, I'm going to hazard after 13 hours of no caloric intake, their glycogen stores are NOT at 2000 kcals.

    Do the math. A 180 lb man has a BMR of 1760 calories and a TDEE of around 2400 calories. Given a starting point of 1900 available calories from glycogen after dinner, if he burned nothing but glycogen over the next 13 hours (he doesn't) he would STILL have 600 calories of available glycogen at 6am.

    400(liver)+1500(muscle)=1900 available calories from glycogen.
    2400*13/24=1300 calories burned from 5pm-6am.

    2000-1300=600 calories from glycogen @ 6am.

    Given that fat is the primary fuel source at rest, the actual number is much higher.


  • TimothyFish
    TimothyFish Posts: 4,925 Member
    FunkyTobias wrote: »
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    ninerbuff wrote: »
    coreyreichle wrote: »
    My opinion is that if you're burning 400-700 calories from a run, and not eating, it's a pretty dumb idea to do.
    In your opinion why is it dumb? If you have 400-700 calories of stored glycogen in your system to do it, what is it affecting?

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...
    They didn't use it up sleeping. Fat is the primary source of energy at rest.

    A.C.E. Certified Personal and Group Fitness Trainer
    IDEA Fitness member
    Kickboxing Certified Instructor
    Been in fitness for 30 years and have studied kinesiology and nutrition
    9285851.png

    I'm sure they didn't. But, given that most people eat dinner at 5PM, are awake until at least 9PM, and wake around 6AM to go and work out, I'm going to hazard after 13 hours of no caloric intake, their glycogen stores are NOT at 2000 kcals.

    Do the math. A 180 lb man has a BMR of 1760 calories and a TDEE of around 2400 calories. Given a starting point of 1900 available calories from glycogen after dinner, if he burned nothing but glycogen over the next 13 hours (he doesn't) he would STILL have 600 calories of available glycogen at 6am.

    400(liver)+1500(muscle)=1900 available calories from glycogen.
    2400*13/24=1300 calories burned from 5pm-6am.

    2000-1300=600 calories from glycogen @ 6am.

    Given that fat is the primary fuel source at rest, the actual number is much higher.


    That is sort of true. The problem is that the body begins to shut down when the glycogen in the liver drops too low, whether there is glycogen elsewhere or not. Of course, such a person wouldn't deplete that much glycogen in the liver while he sleeps either, but if his overall glycogen had dropped to 600 calories worth, that in the liver would be so low that he would be in trouble before stepping out the door.
  • rjmudlax13
    rjmudlax13 Posts: 900 Member
    edited May 2015
    I hate it. I get nauseous and dizzy. Sometimes I feel like I'm gonna faint. I need to eat first then wait a couple hours before doing cardio.

    However, I know some people love it. I guess it's a matter of preference.

    As far as weight loss is concerned there really isn't a benefit. You lose weight with an overall calorie deficit. Timing of meals does nothing.
  • saruuhm
    saruuhm Posts: 71 Member
    Thanks everyone I really appreciate the feedback!
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