Opinions and results on fasted cardio?
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They didn't use it up sleeping. Fat is the primary source of energy at rest.coreyreichle wrote: »
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?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.
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Been in fitness for 30 years and have studied kinesiology and nutrition
I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...
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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.0 -
FunkyTobias wrote: »coreyreichle wrote: »
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?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.
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
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.
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.0 -
I get dizzy, light-headed, and faint if I don't eat something before
. 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 
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coreyreichle wrote: »FunkyTobias wrote: »coreyreichle wrote: »
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?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.
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
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.
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.
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coreyreichle wrote: »
They didn't use it up sleeping. Fat is the primary source of energy at rest.coreyreichle wrote: »
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?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.
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
I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...
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
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.
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FunkyTobias wrote: »coreyreichle wrote: »
They didn't use it up sleeping. Fat is the primary source of energy at rest.coreyreichle wrote: »
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?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.
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
I'm going to guess most people don't have 400-700 of calories in stored glycogen after waking up...
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
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.0 -
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.0 -
Thanks everyone I really appreciate the feedback!0
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