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"Sixteen obese adults (n 8 women and 8 men; age 34.6 (sd 9.5)"
That's a pretty small sample size for a study with sooo many potential variables. Why do they do this? You can't have much confidence in the findings when an experiment like this, by it's nature, has LOTS of variables, then they use a small sample. It doesn't make sense.0 -
probably cost. But it's not the only test of it's type. I think that considering how many research studies have been done on Thermogenesis and DIT already, you can take a whole bunch of variables out of the equation. Not that this study proves beyond a reasonable doubt, and in that regard I agree with you, it's to small to be conclusive, but it does prove a hypothesis, now if others can correlate the results with larger tests, I think this one could be seen as ground breaking (relatively speaking).
FYI, this is how a lot of research is conducted, they first do the study with a small group, if results are as predicted, they look for grants to perform larger studies, if there's enough interest, they get the grant and bingo, large scale studies. It's pretty rare that a study is done on a large group without first testing the hypothesis on a small control, it's just to expensive to bring in hundreds of people for testing over and over again.0 -
Marking for furture posts.0
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bump0
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What do you think about these studies that show increased metabolic rate after 36-48 hours of fasting?
Am J Clin Nutr. 2000 Jun;71(6):1511-5.
Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine.
Zauner C, Schneeweiss B, Kranz A, Madl C, Ratheiser K, Kramer L, Roth E, Schneider B, Lenz K.
http://www.ncbi.nlm.nih.gov/pubmed/10837292
Am J Physiol. 1990 Jan;258(1 Pt 2):R87-93.
Enhanced thermogenic response to epinephrine after 48-h starvation in humans.
Mansell PI, Fellows IW, Macdonald IA.
http://www.ncbi.nlm.nih.gov/pubmed/24057170 -
What do you think about these studies that show increased metabolic rate after 36-48 hours of fasting?
Am J Clin Nutr. 2000 Jun;71(6):1511-5.
Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine.
Zauner C, Schneeweiss B, Kranz A, Madl C, Ratheiser K, Kramer L, Roth E, Schneider B, Lenz K.
http://www.ncbi.nlm.nih.gov/pubmed/10837292
Am J Physiol. 1990 Jan;258(1 Pt 2):R87-93.
Enhanced thermogenic response to epinephrine after 48-h starvation in humans.
Mansell PI, Fellows IW, Macdonald IA.
http://www.ncbi.nlm.nih.gov/pubmed/2405717
You should read the article I posted, it explains why all this happens. But essentially for the first 60 to 72 hours of a large deficit period (can be a fast, but doesn't have to be) the body uses it's stored glycogen as it's primary fuel substrate, during this phase, the metabolism stays the same, and in some cases actually rises, but at about that 72 hour limit (give or take) the glycogen runs out, and the body starts converting to a Krebs cycle metabolism. That means higher protein substrate for energy as well as fat, but because of the lack of incoming carbohydrates, insulin and cortisol changes how the body requests fuel, basically telling the body to store more fat and burn more protein (this is over simplified, but essentially correct).0 -
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Adding to my topics... will come back and read the posted articles soon!!0
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Saving this for later0
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I want to know what you guys all think. Lets make this interactive folks.0
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I still have to read that PDF you provided. :laugh:0
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OK, I'll bite.
This is quite intriguing, because he seems to be investigating not just the fasting period but the types of foods fasted from. Essentially, if I'm understanding correctly, the continued ingestion of carbohydrates is necessary to encourage fat stores rather than protein stores to be used as an energy source? So, in my micro-understanding, keep the glycogen coming?
Correct me if I'm wrong.
Also, it seems to be OK to engage in intermittent fasting according to this.
Or am I just confused? I skimmed and it's early.
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on the original paper I posted? I'm not sure you can make that conclusion specifically. They used something called a glucose clamp to regulate glucose in the blood (along with the insulin clamp as well to do the same with free insulin in the blood), but this was done only to create a stable glucose ratio in the blood so that they could accurately gauge how fast the thermogenic response to glucose was.
One thing I did notice upon re-reading this research was that while the original 72 hour time stamp where the body goes into "starvation mode" (or thermogenic conservation as the author calls it) is accurate for someone in a fasting state, it actually looks like it takes a little longer for someone just "underfeeding", up to 7 days depending. Which makes sense I guess, as the more carbohydrates you add to the system, the longer you delay that total change over to a gluconeogenesis and ketogenesis based system.
What really got my interest was the hypothesis about the Catecholamine-induced thermogenesis. They theorize that catecholamine (basically the fight or flight hormone) can stimulate different thermogenic pathways in the body. I'd love to read more about that. I might look it up.
Who knows, maybe this is the beginnings of a new type of exercise regimen, "Fear based training"
I could make millions! LOL!0 -
on the original paper I posted? I'm not sure you can make that conclusion specifically. They used something called a glucose clamp to regulate glucose in the blood (along with the insulin clamp as well to do the same with free insulin in the blood), but this was done only to create a stable glucose ratio in the blood so that they could accurately gauge how fast the thermogenic response to glucose was.
One thing I did notice upon re-reading this research was that while the original 72 hour time stamp where the body goes into "starvation mode" (or thermogenic conservation as the author calls it) is accurate for someone in a fasting state, it actually looks like it takes a little longer for someone just "underfeeding", up to 7 days depending. Which makes sense I guess, as the more carbohydrates you add to the system, the longer you delay that total change over to a gluconeogenesis and ketogenesis based system.
What really got my interest was the hypothesis about the Catecholamine-induced thermogenesis. They theorize that catecholamine (basically the fight or flight hormone) can stimulate different thermogenic pathways in the body. I'd love to read more about that. I might look it up.
Who knows, maybe this is the beginnings of a new type of exercise regimen, "Fear based training"
I could make millions! LOL!
Is "Catecholamine" the same as cortisol? I thought cortisol (fight or flight chemical) was bad for weight loss...
isn't "fear based training" what Jillian Michaels does? She's certainly made millions....0 -
on the original paper I posted? I'm not sure you can make that conclusion specifically. They used something called a glucose clamp to regulate glucose in the blood (along with the insulin clamp as well to do the same with free insulin in the blood), but this was done only to create a stable glucose ratio in the blood so that they could accurately gauge how fast the thermogenic response to glucose was.
One thing I did notice upon re-reading this research was that while the original 72 hour time stamp where the body goes into "starvation mode" (or thermogenic conservation as the author calls it) is accurate for someone in a fasting state, it actually looks like it takes a little longer for someone just "underfeeding", up to 7 days depending. Which makes sense I guess, as the more carbohydrates you add to the system, the longer you delay that total change over to a gluconeogenesis and ketogenesis based system.
What really got my interest was the hypothesis about the Catecholamine-induced thermogenesis. They theorize that catecholamine (basically the fight or flight hormone) can stimulate different thermogenic pathways in the body. I'd love to read more about that. I might look it up.
Who knows, maybe this is the beginnings of a new type of exercise regimen, "Fear based training"
I could make millions! LOL!
Is "Catecholamine" the same as cortisol? I thought cortisol (fight or flight chemical) was bad for weight loss...
isn't "fear based training" what Jillian Michaels does? She's certainly made millions....
lol, I think JM is more annoyance based training.
to answer your question, no Catecholamines is different from cotisol, Catecholamines are neurotransmitters produced in the brain that affects the brain (think dopamine), along with the sympathetic nervous system, where cortisol is a stress hormone produced by the adrenal gland that affects glucose levels in the blood and also suppresses the immune system. Though a rise in both can occur during stressful situations, I believe cortisol's main function is to provide more fast energy for action where Catecholamines are deigned to increase functional awareness in the body (hyper senses, like when you are really afraid, have you ever notice that you see things better, and hear sounds more acutely, that's partly to do with Catecholamines).
Both have their upsides and downsides though. I know that stimulating cortisol production during heavy exercise is a good thing, especially during explosion type training (like plyometrics or HIIT training), I wonder if there would be a way for us to take advantage of the mind enhancing effects of Catecholamines. Either via suppliment, or some kind of specific warm up regimen that would induce that kind of chemical response (maybe watching something terrifying right before you work out? dunno.) It's something to think about.0 -
Seriously you guys are going to kill me. I remember reading about how fight catecholamines were tied into something about weight loss, but I don't remember where. Now I have to go track that down.on the original paper I posted? I'm not sure you can make that conclusion specifically. They used something called a glucose clamp to regulate glucose in the blood (along with the insulin clamp as well to do the same with free insulin in the blood), but this was done only to create a stable glucose ratio in the blood so that they could accurately gauge how fast the thermogenic response to glucose was.
One thing I did notice upon re-reading this research was that while the original 72 hour time stamp where the body goes into "starvation mode" (or thermogenic conservation as the author calls it) is accurate for someone in a fasting state, it actually looks like it takes a little longer for someone just "underfeeding", up to 7 days depending. Which makes sense I guess, as the more carbohydrates you add to the system, the longer you delay that total change over to a gluconeogenesis and ketogenesis based system.
What really got my interest was the hypothesis about the Catecholamine-induced thermogenesis. They theorize that catecholamine (basically the fight or flight hormone) can stimulate different thermogenic pathways in the body. I'd love to read more about that. I might look it up.
Who knows, maybe this is the beginnings of a new type of exercise regimen, "Fear based training"
I could make millions! LOL!
Is "Catecholamine" the same as cortisol? I thought cortisol (fight or flight chemical) was bad for weight loss...
isn't "fear based training" what Jillian Michaels does? She's certainly made millions....
lol, I think JM is more annoyance based training.
to answer your question, no Catecholamines is different from cotisol, Catecholamines are neurotransmitters produced in the brain that affects the brain (think dopamine), along with the sympathetic nervous system, where cortisol is a stress hormone produced by the adrenal gland that affects glucose levels in the blood and also suppresses the immune system. Though a rise in both can occur during stressful situations, I believe cortisol's main function is to provide more fast energy for action where Catecholamines are deigned to increase functional awareness in the body (hyper senses, like when you are really afraid, have you ever notice that you see things better, and hear sounds more acutely, that's partly to do with Catecholamines).
Both have their upsides and downsides though. I know that stimulating cortisol production during heavy exercise is a good thing, especially during explosion type training (like plyometrics or HIIT training), I wonder if there would be a way for us to take advantage of the mind enhancing effects of Catecholamines. Either via suppliment, or some kind of specific warm up regimen that would induce that kind of chemical response (maybe watching something terrifying right before you work out? dunno.) It's something to think about.0 -
This connection could also be tied to the idea that coffee before a workout can contribute to a better burn during the workout (I've noticed this through the decidedly non-scientific experiment of drinking a double espresso before a workout and then checking my HRM).
Check this out:http://books.google.ca/books?id=oI6LtxfEKkwC&pg=PA105&lpg=PA105&dq=coffee+and+catecholamines&source=bl&ots=Ck4nGAUQox&sig=gpQECc1GfOGYQJNENEdIuRYu1bk&hl=en&ei=EILlTNrmIYi6sAO_2uWxCw&sa=X&oi=book_result&ct=result&resnum=4&ved=0CDQQ6AEwAw#v=onepage&q=coffee and catecholamines&f=false
(should link to a book theorizing that coffee releases catecholamines.)
has nerdgasm, falls over...0 -
And, from all that, THIS is the part that I get! Okay, somebody might have to do lots of explaining on the other stuff! :laugh:has nerdgasm, falls over...0 -
This connection could also be tied to the idea that coffee before a workout can contribute to a better burn during the workout (I've noticed this through the decidedly non-scientific experiment of drinking a double espresso before a workout and then checking my HRM).
Check this out:http://books.google.ca/books?id=oI6LtxfEKkwC&pg=PA105&lpg=PA105&dq=coffee+and+catecholamines&source=bl&ots=Ck4nGAUQox&sig=gpQECc1GfOGYQJNENEdIuRYu1bk&hl=en&ei=EILlTNrmIYi6sAO_2uWxCw&sa=X&oi=book_result&ct=result&resnum=4&ved=0CDQQ6AEwAw#v=onepage&q=coffee and catecholamines&f=false
(should link to a book theorizing that coffee releases catecholamines.)
has nerdgasm, falls over...
big fan of coffee before workouts. Coffiene breaks down to Paraxanthine (and a couple others, but mainly this one) which stimulates lipidosys. this means more Free fatty acids in the blood, I.E. more fast ATP generation, which means more high energy work before your muscles get all anaerobic and stuff.0
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