How many carbs do you really need??

Mike ODonnell · 10-13-2006, 02:13 PM

Ok here's what I have on paper: Your body (depending on muscle size and other factors) will have:
- 30g of glucose in the blood
- 90g of glycogen in the liver
- 350-400g of glycogen stored in muscles

so all in all you have at full stores about 500+g of glycogen availble to use....like I said...very rough numbers.

Ok...so in determining how many carbs one does need per day for bodily functions and maximum muscle glycogen replenishment, we look at different workouts and their affect:

Brain (Glucose hog) needs like @30g per day to function I believe

Now for workouts....I guess it all depends on the type and duration, so for arguments sake lets go with:
a) traditional long distance for 60min (aka a 10k)
b) HIT Metcon workout Crossfit (20 or so min)
c) ME style workout doing sets of 5reps or lower (45min)
d) Old fashioned RE style (body building) with sets of 8-12.

What is the glycogen deficit for each of those types of activities? (so you can know how much g of carbs you need for maximum glycogen replenishment)

Now if you are a fat burning machine (switched the metabolism around), how do those numbers now change in comparison to before? (Do you now burn more fat than glycogen)

In other words...really how many carbs does one need per day for optimal body and muscle recovery depending on their style of training?

Greg Battaglia · 10-13-2006, 02:59 PM

That's a great question. I know that when on a low carb diet the body will indeed burn a much larger portion of it's calories as fat, but I'm not sure exactly how much more. I also know that the brain does not *require* glucose for optimal function, and actually functions more efficiently on ketones once fat adaptation occurs. Other than that, I'm just as stomped as you. In fact, as far as I know there is no answer to this question because I don't believe it has ever been studied.

Kevin McKay · 10-13-2006, 03:02 PM

I am sure it varies dramatically from individual to individual but I was recently shocked to discover how great I felt after cutting my zone blocks in 1/2. I currently eat about 60-80 a day 1/2 fruit 1/2 veggies and feel awesome! Much better than I felt at <30 a day "md" or 160 "zone"
Best I have felt in a long time think maybe I found my personal carb sweet spot, also I do cycle my carbs up to 160 on the weekends so maybe that factors in as well.

Mike ODonnell · 10-13-2006, 03:09 PM

Hey I knew it was a great question :biggrinthumb:

I know it will be individual because of metabolism..but I am always curious to know how much glycogen I am really burning during a specific training event...so I can try and guess how much additional carbs I will need for full muscle glycogen replenishment...all in all probably not going to get one simple answer on it.

For example..I do a Metcon...20min...HIT stuff...probably burn what 300cal?...but then my metabolism is fired up for hours...so do I burn 1000cal in 2 hours just from the workout? And if that is the case...what is the % of glycogen used of the 1000cal in a HIT workout...75...85%? Some might argue that muscle glycogen is completely drained in about 20min of HIT or heavy lifting.....but now say I am doing ME stuff...prob don't need excessive glycogen and can burn a 50-50 ratio with fat..

Probably just nitpicking around all this stuff...but I love to learn and know everything that is going on....which will drive me nuts considering there will never be one right answer for everyone...

Mike ODonnell · 10-13-2006, 03:10 PM

PS...yes I function so much better on lower carbohydrate normally <100g...but also like the feeling of carb loads on the weekends when I feel I get more of my strength back....

Charlie Jackson · 10-13-2006, 04:31 PM

as far as I know there is no answer to this question because I don't believe it has ever been studied.

endurance athletes have studied the •••• out of this for obvious reasons. You need to get your VO2 max tested and some other things tested and you can get a decent estimate.

Ragnar Speicher · 10-14-2006, 03:08 AM

mike, really good question that is. i've been wondering too... (though my thinking was less complex)
here's some research that gives some good hints:

"It is generally acknowledged that even without a glycogen-depleting period of exercise, trained athletes can store maximal amounts of muscle glycogen if fed a carbohydrate-rich diet for 3 days. What has never been examined is whether under these conditions this many days are necessary for the content of muscle glycogen to attain these high levels. To examine this issue, eight endurance-trained male athletes were asked to eat 10 g.day(-1).kg(-1) body mass of high-carbohydrate foods having a high glycaemic index over 3 days, while remaining physically inactive. Muscle biopsies were taken prior to carbohydrate loading and after 1 and 3 days of eating the carbohydrate-rich diet. Muscle glycogen content increased significantly ( P<0.05) from pre-loading levels of [mean (SE)] 95 (5) to 180 (15) mmol.kg(-1) wet mass after only 1 day, and remained stable afterwards despite another 2 days of carbohydrate-rich diet. Densitometric analyses of muscle sections stained with periodic acid-Schiff not only supported these findings, but also indicated that only 1 day of high carbohydrate intake was required for glycogen stores to reach maximal levels in types I, IIa, and IIb muscle fibres. In conclusion, these findings showed that combining physical inactivity with a high intake of carbohydrate enables trained athletes to attain maximal muscle glycogen contents within only 24 h."

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstra ctPlus&list_uids=12111292&query_hl=4&itool=pubmed_ docsum

"PURPOSE: One limitation shared by all published carbohydrate-loading regimens is that 2-6 d are required for the attainment of supranormal muscle glycogen levels. Because high rates of glycogen resynthesis are reported during recovery from exercise of near-maximal intensity and that these rates could in theory allow muscle to attain supranormal glycogen levels in less than 24 h, the purpose of this study was to examine whether a combination of a short bout of high-intensity exercise with 1 d of a high-carbohydrate intake offers the basis for an improved carbohydrate-loading regimen. METHODS: Seven endurance-trained athletes cycled for 150 s at 130% VO2peak followed by 30 s of all-out cycling. During the following 24 h, each subject was asked to ingest 12 g.kg-1 of lean body mass (the equivalent of 10.3 g.kg-1 body mass) of high-carbohydrate foods with a high glycemic index. RESULTS: Muscle glycogen increased from preloading levels (+/- SE) of 109.1 +/- 8.2 to 198.2 +/- 13.1 mmol.kg-1 wet weight within only 24 h, these levels being comparable to or higher than those reported by others over a 2- to 6-d regimen. Densitometric analysis of muscle sections stained with periodic acid-Schiff not only corroborated these findings but also indicated that after 24 h of high-carbohydrate intake, glycogen stores reached similar levels in Type I, IIa, and IIb muscle fibers. CONCLUSION: This study shows that a combination of a short-term bout of high-intensity exercise followed by a high-carbohydrate intake enables athletes to attain supranormal muscle glycogen levels within only 24 h."

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstra ctPlus&list_uids=12048325&query_hl=4&itool=pubmed_ docsum

Larry Lindenman · 10-14-2006, 05:12 AM

Not only is it a good question, I think it's the key to dietary efficiency! Find that number, get your 1 to 1.5g Protein per, then up the calories to maintenance or above mainteince with healthy fats and you've got your individualized nutrition program. Obviously this number is going to be different for everyone due to numerous factors (muscle mass for one), and will change as body composition changes. This need to be played with individually.

Nikki Young · 10-16-2006, 02:10 AM

Greg, i thought the brain ran off 80% fat for energy, and 20% carbs, and if the body doesn't consume some amount of carbs for the brain to use to function correctly, it will start to eat itself, in terms of muscle. I read your coment as the brain is pretty much 100% fat for fuel, sorry if that wasn't what you implied, i just want to clear up my facts.

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10-13-2006, 02:13 PM	#1
Mike ODonnell Member Profile: Join Date: Jun 2008 Location: Atlanta GA Posts: 1,566	Ok here's what I have on paper: Your body (depending on muscle size and other factors) will have: - 30g of glucose in the blood - 90g of glycogen in the liver - 350-400g of glycogen stored in muscles so all in all you have at full stores about 500+g of glycogen availble to use....like I said...very rough numbers. Ok...so in determining how many carbs one does need per day for bodily functions and maximum muscle glycogen replenishment, we look at different workouts and their affect: Brain (Glucose hog) needs like @30g per day to function I believe Now for workouts....I guess it all depends on the type and duration, so for arguments sake lets go with: a) traditional long distance for 60min (aka a 10k) b) HIT Metcon workout Crossfit (20 or so min) c) ME style workout doing sets of 5reps or lower (45min) d) Old fashioned RE style (body building) with sets of 8-12. What is the glycogen deficit for each of those types of activities? (so you can know how much g of carbs you need for maximum glycogen replenishment) Now if you are a fat burning machine (switched the metabolism around), how do those numbers now change in comparison to before? (Do you now burn more fat than glycogen) In other words...really how many carbs does one need per day for optimal body and muscle recovery depending on their style of training?

10-13-2006, 02:59 PM	#2
Greg Battaglia Member Profile: Join Date: Nov 2005 Location: Springfield PA Posts: 468	That's a great question. I know that when on a low carb diet the body will indeed burn a much larger portion of it's calories as fat, but I'm not sure exactly how much more. I also know that the brain does not require glucose for optimal function, and actually functions more efficiently on ketones once fat adaptation occurs. Other than that, I'm just as stomped as you. In fact, as far as I know there is no answer to this question because I don't believe it has ever been studied.

10-13-2006, 03:02 PM	#3
Kevin McKay Member Profile: Join Date: Feb 2006 Location: albany ca Posts: 1,110	I am sure it varies dramatically from individual to individual but I was recently shocked to discover how great I felt after cutting my zone blocks in 1/2. I currently eat about 60-80 a day 1/2 fruit 1/2 veggies and feel awesome! Much better than I felt at <30 a day "md" or 160 "zone" Best I have felt in a long time think maybe I found my personal carb sweet spot, also I do cycle my carbs up to 160 on the weekends so maybe that factors in as well.

10-13-2006, 03:09 PM	#4
Mike ODonnell Member Profile: Join Date: Jun 2008 Location: Atlanta GA Posts: 1,566	Hey I knew it was a great question :biggrinthumb: I know it will be individual because of metabolism..but I am always curious to know how much glycogen I am really burning during a specific training event...so I can try and guess how much additional carbs I will need for full muscle glycogen replenishment...all in all probably not going to get one simple answer on it. For example..I do a Metcon...20min...HIT stuff...probably burn what 300cal?...but then my metabolism is fired up for hours...so do I burn 1000cal in 2 hours just from the workout? And if that is the case...what is the % of glycogen used of the 1000cal in a HIT workout...75...85%? Some might argue that muscle glycogen is completely drained in about 20min of HIT or heavy lifting.....but now say I am doing ME stuff...prob don't need excessive glycogen and can burn a 50-50 ratio with fat.. Probably just nitpicking around all this stuff...but I love to learn and know everything that is going on....which will drive me nuts considering there will never be one right answer for everyone...

10-13-2006, 03:10 PM	#5
Mike ODonnell Member Profile: Join Date: Jun 2008 Location: Atlanta GA Posts: 1,566	PS...yes I function so much better on lower carbohydrate normally <100g...but also like the feeling of carb loads on the weekends when I feel I get more of my strength back....

10-13-2006, 04:31 PM	#6
Charlie Jackson Banned Profile: Join Date: Mar 2006 Location: Santa Carlos New Mexico Posts: 204	as far as I know there is no answer to this question because I don't believe it has ever been studied. endurance athletes have studied the •••• out of this for obvious reasons. You need to get your VO2 max tested and some other things tested and you can get a decent estimate.

10-14-2006, 03:08 AM	#7
Ragnar Speicher Member Profile: Join Date: Jul 2006 Location: Siegen NRW Posts: 37	mike, really good question that is. i've been wondering too... (though my thinking was less complex) here's some research that gives some good hints: "It is generally acknowledged that even without a glycogen-depleting period of exercise, trained athletes can store maximal amounts of muscle glycogen if fed a carbohydrate-rich diet for 3 days. What has never been examined is whether under these conditions this many days are necessary for the content of muscle glycogen to attain these high levels. To examine this issue, eight endurance-trained male athletes were asked to eat 10 g.day(-1).kg(-1) body mass of high-carbohydrate foods having a high glycaemic index over 3 days, while remaining physically inactive. Muscle biopsies were taken prior to carbohydrate loading and after 1 and 3 days of eating the carbohydrate-rich diet. Muscle glycogen content increased significantly ( P<0.05) from pre-loading levels of [mean (SE)] 95 (5) to 180 (15) mmol.kg(-1) wet mass after only 1 day, and remained stable afterwards despite another 2 days of carbohydrate-rich diet. Densitometric analyses of muscle sections stained with periodic acid-Schiff not only supported these findings, but also indicated that only 1 day of high carbohydrate intake was required for glycogen stores to reach maximal levels in types I, IIa, and IIb muscle fibres. In conclusion, these findings showed that combining physical inactivity with a high intake of carbohydrate enables trained athletes to attain maximal muscle glycogen contents within only 24 h." http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstra ctPlus&list_uids=12111292&query_hl=4&itool=pubmed_ docsum "PURPOSE: One limitation shared by all published carbohydrate-loading regimens is that 2-6 d are required for the attainment of supranormal muscle glycogen levels. Because high rates of glycogen resynthesis are reported during recovery from exercise of near-maximal intensity and that these rates could in theory allow muscle to attain supranormal glycogen levels in less than 24 h, the purpose of this study was to examine whether a combination of a short bout of high-intensity exercise with 1 d of a high-carbohydrate intake offers the basis for an improved carbohydrate-loading regimen. METHODS: Seven endurance-trained athletes cycled for 150 s at 130% VO2peak followed by 30 s of all-out cycling. During the following 24 h, each subject was asked to ingest 12 g.kg-1 of lean body mass (the equivalent of 10.3 g.kg-1 body mass) of high-carbohydrate foods with a high glycemic index. RESULTS: Muscle glycogen increased from preloading levels (+/- SE) of 109.1 +/- 8.2 to 198.2 +/- 13.1 mmol.kg-1 wet weight within only 24 h, these levels being comparable to or higher than those reported by others over a 2- to 6-d regimen. Densitometric analysis of muscle sections stained with periodic acid-Schiff not only corroborated these findings but also indicated that after 24 h of high-carbohydrate intake, glycogen stores reached similar levels in Type I, IIa, and IIb muscle fibers. CONCLUSION: This study shows that a combination of a short-term bout of high-intensity exercise followed by a high-carbohydrate intake enables athletes to attain supranormal muscle glycogen levels within only 24 h." http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstra ctPlus&list_uids=12048325&query_hl=4&itool=pubmed_ docsum

10-14-2006, 05:12 AM	#8
Larry Lindenman Affiliate Profile: Join Date: Jul 2003 Location: Chicago Illinois Posts: 2,769	Not only is it a good question, I think it's the key to dietary efficiency! Find that number, get your 1 to 1.5g Protein per, then up the calories to maintenance or above mainteince with healthy fats and you've got your individualized nutrition program. Obviously this number is going to be different for everyone due to numerous factors (muscle mass for one), and will change as body composition changes. This need to be played with individually.

10-16-2006, 02:10 AM	#9
Nikki Young Member Profile: Join Date: Sep 2005 Location: Canberra ACT Posts: 458	Greg, i thought the brain ran off 80% fat for energy, and 20% carbs, and if the body doesn't consume some amount of carbs for the brain to use to function correctly, it will start to eat itself, in terms of muscle. I read your coment as the brain is pretty much 100% fat for fuel, sorry if that wasn't what you implied, i just want to clear up my facts.