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NeoRetroGrouch
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Discussion Starter · #1 ·
Sugars….

I am not a pure biologist or chemist, but here is a very general outline so that we are all talking about the same thing. Feel free to correct significant errors or add important details.

Simple sugar= A single molecule sugar, monosaccharide. Some examples are:
-Glucose (also called dextrose) – the one we generally use directly within the cells.
-Fructose – ‘fruit sugar’ transformed to glucose by the liver. Common sources= fruit or from corn where some of the glucose has been converted.
-Galactose – From milk sugar. Can also be used by the cells directly.

Two molecule sugars. Disaccharides. Some examples:
-Sucrose – ‘Table sugar’ Common sources= sugar cane and sugar beets. Made up of one molecule of glucose and one of fructose. Split in the stomach/intestine before being transferred into the blood stream.
-Lactose – ‘Milk sugar’ Source= milk. Made up of Galactose and glucose. Also split in digestive system. Lactose intolerant= do not have (enough) this ‘splitting’ enzyme.
-Maltose – Probably some in your non-light beer. A glucose-glucose disaccharide.

The rest are not sugars, but are made up of sugars.

Trisaccharides – 3 sugars
- Raffinose – Made up of galactose-fructose-glucose. We (humans) do not have the enzyme to break down raffinose. It, therefore, travels into the large intestine where it is broken down and digested by bacteria produce very smelly gasses. Source= veggies, grains and especially beans.

Dextrins – Longer chains (but not too long???) polysaccharides made up of glucose.
-Maltodextrin is easily broken down in humans and used at about the same rate as glucose. It is used as the sugar source in brewing and also directly in some energy gels and drinks.

Starch – Very long chains of glucose. Sugar storage for plants. Digestible by humans; first to maltodextrines and then to glucose. Sources= potatoes, grains, rice.

Glycogen – Very long chains of glucose. Sugar storage for animals.

TF
 

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TurboTurtle said:
-Maltodextrin is easily broken down in humans and used at about the same rate as glucose. It is used as the sugar source in brewing and also directly in some energy gels and drinks.
So here's a question. Does this mean malto is used the same as simpler sugars like glucose or sucrose during exercise?

That would be my guess, but my impression is that there is some marketing that it gives a "slower, steady" supply of energy.
 

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NeoRetroGrouch
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Discussion Starter · #5 ·
Dwayne Barry said:
So here's a question. Does this mean malto is used the same as simpler sugars like glucose or sucrose during exercise?

That would be my guess, but my impression is that there is some marketing that it gives a "slower, steady" supply of energy.
It is my understanding than at least one study indicated that (how's that for CYA) the maltodextrin breaks down at about the same rate as the maximum transfer to the blood stream which maintains the optimum concentration for transfer. If you just ingested an excess of glucose, the concentration would be too high for optimum passive transfer. Do not know about sucrose or whether this is still true in light of the more recent findings of a possible increase in carbo transfer with a combination of glucose and fructose. - TF
 

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TurboTurtle said:
-Maltose – Probably some in your non-light beer. A glucose-glucose disaccharide.


TF
There might have been some Maltose in the Wort but not the beer. The yeast likes to turn that into alcohol.
however if you want a sweet beer you can add some lactose. (it isn't fermentable)
 

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TurboTurtle said:
It is my understanding than at least one study indicated that (how's that for CYA) the maltodextrin breaks down at about the same rate as the maximum transfer to the blood stream which maintains the optimum concentration for transfer. If you just ingested an excess of glucose, the concentration would be too high for optimum passive transfer. Do not know about sucrose or whether this is still true in light of the more recent findings of a possible increase in carbo transfer with a combination of glucose and fructose. - TF
I did a little searching and based on what else I've seen, it basically seems like during exercise it is not gastric emptying that limits carbohydrate aborption but the ability to absorb glucose across the intestinal wall. As long as you saturate this response by taking in enough carbs (whether straight glucose or malto or probably dextrose) you can't use more than about 1g/min (60g or 240 kcal per hour). Including fructose seems to be the only way to up this amount, which of course is a good arguement for using regular old evil table sugar to an extent since it breaks down to glucose and fructose.
 

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No Crybabies
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molecules / enzymes

TurboTurtle said:
It is my understanding than at least one study indicated that (how's that for CYA) the maltodextrin breaks down at about the same rate as the maximum transfer to the blood stream which maintains the optimum concentration for transfer. If you just ingested an excess of glucose, the concentration would be too high for optimum passive transfer. Do not know about sucrose or whether this is still true in light of the more recent findings of a possible increase in carbo transfer with a combination of glucose and fructose. - TF
The Hammer Nutrition site and marketing info suggests (or states) that the benefit of maltodextrin over simple sugars is that the transfer limit is determined by the number of *molecules* that can pass over a given amount of time, and since maltodextrin is one molecule that contains twice as much glucose than a simple dextrose molecule, you can absorb more energy in a given time. In fact, that appears to be the entire basis for their marketing, other than an apparent mortal fear of fructose.

I have found maltodextrin to be difficult for me to handle when used on longer rides, and the longer the worse it gets. At high enough concentrations and quantities to avoid bonk, I get horrific gastric distress. I suspect that my system is just not capable of breaking down maltodextrin as quickly as others, or at least I react to having excess undigested sugars in my lower intestings worse than some.

For some odd reason, GU2O seems to work much better. It is a combination of maltodextrin and fructose. It seems to be much more palatable and results in lower gastric distress when used for longer rides. I don't know, are all maltodextrins the same? I can't figure out why some work and some don't.

I'm trying to determine what role the various sugar enzymes (sucrase, maltase, and a bunch of others) play, too. I am concerned that I (and I assume many others) may deplete certain enzymes too rapidly, and may benefit from a supplement. Any thoughts on that? Thanks.
 

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From what little digging I've done it doesn't appear that there is any difference in the rate carbs get into your system whether or not it is glucose or malto, or I would assume even more complex carbs (assuming gastric emptying doesn't become limiting and therefore not get enough carbs get into the intestines). I now very little about digestion physiology but doesn't it all have to be broken down to simple sugars before it crosses the intestines and gets to your blood and eventually your muscles, liver, etc?

The reason fructose offers an advantage is because it has it's own transporter so even though the glucose transporter is saturated, "extra" carbs get in via fructose, so you go from about 1 g/min to 1.5 g/min if you include fructose.
 

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NeoRetroGrouch
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Discussion Starter · #10 · (Edited)
fleck said:
There might have been some Maltose in the Wort but not the beer. The yeast likes to turn that into alcohol.
however if you want a sweet beer you can add some lactose. (it isn't fermentable)
I'm pretty sure that there is some left since to make 'light' beer, they add other bacteria to eat up the excess sugar. - TF

EDIT - Actually, I think they just use an enzyme, not an active culture. - TF
 

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No Crybabies
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what Hammer says

Dwayne Barry said:
From what little digging I've done it doesn't appear that there is any difference in the rate carbs get into your system whether or not it is glucose or malto, or I would assume even more complex carbs (assuming gastric emptying doesn't become limiting and therefore not get enough carbs get into the intestines). I now very little about digestion physiology but doesn't it all have to be broken down to simple sugars before it crosses the intestines and gets to your blood and eventually your muscles, liver, etc?

The reason fructose offers an advantage is because it has it's own transporter so even though the glucose transporter is saturated, "extra" carbs get in via fructose, so you go from about 1 g/min to 1.5 g/min if you include fructose.
Then I can't understand what Hammer is saying, but maybe that's intended:

Here's the deal: simple sugars (glucose, sucrose, fructose, dextrose, etc) need to be mixed in concentrations no higher than 6-8% in order to achieve an acceptable absortion osmolar value of body fluids (280-303 mOsm) and be digested with any efficiency. That's it. The problem is that a 6-8% solution is a pretty weak mix and will only yield about 100 or so calories an hour, which is inadequate for maintaining optimal energy production. Some athletes realize that and try to resolve the problem by making a double or triple strength batch of their simple sugar product. Unfortunately, that solution is now far too concentrated, it's much higher than 6-8% and, unless more water is consumed or added to the mix (at which point the athlete might very well be flirting with over hydration) that concentrated simple sugar solution will not pass the gastric channels. Energy production is compromised and stomach distress is sure to follow.

The same problem occurs when an athlete combines a simple sugar fuel with a complex carbohydrate fuel. The beauty of complex carbs is that they will match body fluid osmolality, not at a 6-8% solution, but a more concentrated 15-18% solution. Even at this seemingly too-high concentration complex carbohydrates (such as maltodextrins/glucose polymers) will empty the stomach at the same efficient rate as normal body fluids and provide substantially more calories (up to three times more) than simple sugar mixtures will. However, when simple sugars and complex carbs are consumed together or near each other, it increases the solution concentration beyond what either source can be efficiently digested at. In other words, when you consume simple sugars and complex carbohydrates together or within close proximity of each other you negate the efficient digestibility of either source. Once again, energy production will be compromised and a variety of stomach issues are likely to occur.

***

The higher the simple sugar content, the higher the solution osmolality, the less of it is absorbed immediately. The longer the chain of sugars linked together as a complex carbohydrate the more of it is absorbed in higher solution because its osmolality is closer to that of body fluids. Therefore, the ideal carbohydrate source for athletes is long-chain complex carbohydrates, which is what all the Hammer Nutrition fuels are comprised of.
http://www.hammernutrition.com/za/H...BRARY&OMI=&AMI=&RETURN_TEXT=Endurance Library
 

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NeoRetroGrouch
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Discussion Starter · #12 ·
Fixed said:
The Hammer Nutrition site and marketing info suggests (or states) that the benefit of maltodextrin over simple sugars is that the transfer limit is determined by the number of *molecules* that can pass over a given amount of time, and since maltodextrin is one molecule that contains twice as much glucose than a simple dextrose molecule, you can absorb more energy in a given time. In fact, that appears to be the entire basis for their marketing, other than an apparent mortal fear of fructose.

I have found maltodextrin to be difficult for me to handle when used on longer rides, and the longer the worse it gets. At high enough concentrations and quantities to avoid bonk, I get horrific gastric distress. I suspect that my system is just not capable of breaking down maltodextrin as quickly as others, or at least I react to having excess undigested sugars in my lower intestings worse than some.

For some odd reason, GU2O seems to work much better. It is a combination of maltodextrin and fructose. It seems to be much more palatable and results in lower gastric distress when used for longer rides. I don't know, are all maltodextrins the same? I can't figure out why some work and some don't.

I'm trying to determine what role the various sugar enzymes (sucrase, maltase, and a bunch of others) play, too. I am concerned that I (and I assume many others) may deplete certain enzymes too rapidly, and may benefit from a supplement. Any thoughts on that? Thanks.
Well, that's Hammer. I've never seen anything that says that anything but simple sugars can cross into the blood stream. Doesn't mean that they can't, just that I would need more than Hammer's word.

They may use different processes to make the dextrin and get slightly different configurations. My guess, though, would be that it is some other ingredient that you are having trouble with. That, or the concentration of the maltodextrin.

Enzymes do not get used up – they are just ‘helpers’. They can keep right on transforming for quite some time. The only thing I have seen on sugar enzyme limitation for healthy adults is the lack of lactase for those who are lactose intolerant. (BTW, studies seem to indicate that only about 10% of those that think they are lactose intolerant, really are.)

TF
 

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NeoRetroGrouch
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Discussion Starter · #13 ·
They are talking about the rate of gastric emptying, not membrane transfer. The rate that the stomach muscles squeeze the material out of the stomach and into the small intestine is controlled by sensors in the small intestine. (High blood sugar concentration also limits gastric emptying, but should not be a problem during intensive exercise since getting more sugar to the blood is the whole point.) These sense the osmolality and chemistry of the small intestine contents. Hammer is claiming that the complex carbohydrate provides the same activation of these sensors at about double the concentration of simple sugars. This means that more carbohydrate would get from the stomach into the intestine.

I'm not sure which is the limiting step during intense exercise with liquid energy sources, but I think that it is the membrane transfer into the blood stream (not gastric emptying). For glucose, there are two transport systems. One is just a passive transfer across the membrane - i.e. fitting though the molecular size holes. The other is an active transport where the glucose molecule (along with a water molecule) attaches to an enzyme which then reconfigures with the glucose now on the other side of the membrane where it (along with the water) is released. (Note that glucose also helps to hydrate.)

As far as I know, the other simple sugars only have the passive transport. Apparently, fructose can utilize sites (fits through different shaped holes) that glucose cannot and therefore can increase the total carbo transfer rate.

We are rapidly approaching (or maybe have already exceeded) the extent of my knowledge on the subject. The enzymatic transfer certainly would be concentration dependent and I would think that the passive system would be also. Purely conjecture, but - perhaps the sensors are located near the intestinal inlet and the dextrin gets further downstream before breaking down and raising the glucose concentration. This would provide a higher transfer rate and yet not limit gastric emptying???

TF

EDIT - Here is a good little bit on gastic emptying. http://www.vivo.colostate.edu/hbooks/pathphys/digestion/stomach/emptying.html
 

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TurboTurtle said:
They are talking about the rate of gastric emptying, not membrane transfer. The rate that the stomach muscles squeeze the material out of the stomach and into the small intestine is controlled by sensors in the small intestine. (High blood sugar concentration also limits gastric emptying, but should not be a problem during intensive exercise since getting more sugar to the blood is the whole point.)
Would this imply that a diabetic with mildly high blood sugar would be restricting gastric emptying and thus carbohydrate absorption? Or would blood sugars need to be extremely high before gastric emptying was limited?
 

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NeoRetroGrouch
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Discussion Starter · #15 ·
kbiker3111 said:
Would this imply that a diabetic with mildly high blood sugar would be restricting gastric emptying and thus carbohydrate absorption? Or would blood sugars need to be extremely high before gastric emptying was limited?
Diabetes is one cause of restricted gastric emptying. I do not know what levels are required. Would a diabetic still have a high blood sugar at the intensity where maximum carbo intake is required. - TF
 

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Simple measure

Fixed said:
Then I can't understand what Hammer is saying, but maybe that's intended
There's a REALLY simple measure of how fast any given food "hits" the bloodstream; it's called glycemic index. One can infer, reasonably, that foods with a lower glycemic index will be "longer lasting" because the lower glycemic index means that those calories last longer. Maltodextrin and glucose both have the same glycemic index. There is no "longer lasting" effect from maltodextrin. Anyone who claims there is has been ignoring the data.
 

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NeoRetroGrouch
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Discussion Starter · #18 ·
Kerry Irons said:
There's a REALLY simple measure of how fast any given food "hits" the bloodstream; it's called glycemic index. One can infer, reasonably, that foods with a lower glycemic index will be "longer lasting" because the lower glycemic index means that those calories last longer. Maltodextrin and glucose both have the same glycemic index. There is no "longer lasting" effect from maltodextrin. Anyone who claims there is has been ignoring the data.
Actually they are claiming that it gets there faster. - TF
 

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faster AND longer

TurboTurtle said:
Actually they are claiming that it gets there faster. - TF
I think they are saying that it both gets in your blood faster (or more in a given time, actually) and it causes less of a "spike" in blood glucose levels.

Is that possible?
 

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NeoRetroGrouch
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Discussion Starter · #20 ·
Fixed said:
I think they are saying that it both gets in your blood faster (or more in a given time, actually) and it causes less of a "spike" in blood glucose levels.

Is that possible?
I don't get that out of what you posted. Also, a 'spike' is not a concern when maximum carb transfer is.

The whole Hammer thing is very vague and 'dances' a lot - it is marketing that sounds like science. For instance, it implies that you can get the same benefit by simply using more of the '6-8% solution' (i.e. Gatorade) except that you may over-hydrate. Is over-hydration really a concern at this point? Are the optimizing the rate of the Gatorade ingestion? Lot's of questions. And, of course, the whole thing was started by another marketing lab - the Gatorade Institute or whatever they call it.

TF
 
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