Terry Morse wrote:
> In article <[email protected]>,
> Peter <[email protected]> wrote:
>
>
>>Terry Morse wrote:
>>
>>
>>>"Fructose, sucrose, glucose and other simple sugars...absorb
>>>poorly, cause wild energy fluctuations, and require excess water
>>>consumption...Complex carbohydrates...are the wisest choice for
>>>endurance athletes, as they allow your digestive system to rapidly
>>>and efficienlty process a greater volume of calories, providing
>>>steady energy." - S. Born, "The Endurance Athlete's Guide to
>>>Suceess", an E-Caps/Hammer Nutrition publication
>>>
>>>Granted, this is coming from a company that's trying to sell its own
>>>line of sports nutrition products.
>>
>>Do they give any justification for those statements?
>
>
> Yes. From the same document:
>
> "Just as important, though, is the fact that simple sugars, unlike
> complex carbohydrates, take longer and require more fluid to empty
> from the stomach and GI tract."
This statement totally ignores the fact that complex carbohydrates can't
be absorbed from the stomach and GI tract at all - they first have to be
broken down into monosaccharides (simple single sugars like glucose and
fructose). From
http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_sugars.html:
"Particularly important dietary carbohydrates include starch and
disaccharides such as lactose and sucrose. None of these molecules can
be absorbed for the simple reason that they cannot cross cell membranes
unaided and, unlike the situation for monosaccharides, there are no
transporters to carry them across. ... Polysaccharides and disaccharides
must be digested to monosaccharides prior to absorption"
> "This is due to a physiological
> feature known as osmolality...If the osmolality of your sports drink
> deviates from body fluid levels, it will not absorb. A simple sugar
> drink will only match regular body fluid osmolality at a very weak
> 6-8% concentration; otherwise, it will remain in the stomach until
> sufficiently diluted.
Anyone who has mildly 'bonked' and then been rather quickly revitalized
by drinking a coke or other sugar-rich drink will recognize that the
sugar didn't just sit in the stomach waiting for them to drink lots of
additional water to achieve this dilution. Instead, the sugar passes
quickly to the small intestine and is absorbed directly through the
intestinal wall into the bloodstream. If the sugar is sucrose (a
disaccharide) then it is first broken down by enzymes to its components:
glucose and fructose, but that's a very rapid process compared to the
necessary breakdown of starches and other complex carbohydrates.
...With a simple sugar drink, you're left with
> three bad choices. You can drink a 6-8% solution, but you'll get too
> few calories. You can drink a lot of a 6-8% solution to get adequate
> calories, but you'll overfill on fluid, or you can make a
> concentrated drink to get enough calories, but then you'll get poor
> absorption. In any case, you're done in. Simple sugar drinks just
> don't cut it for the endurance athlete."
So their claim is that given two possible processes:
1) monosaccharide -> absorption by bloodstream -> ATP production in body
cells; and
2) polysaccharide -> breakdown by enzymes to monosaccharides ->
absorption by bloodstream -> ATP production in body cells;
that somehow 2) is faster and more efficient even though it's the same
as 1) but with the additional first step.
Looks like magic to me. The only explanation I can see is what you
mentioned previously: "this is coming from a company that's trying to
sell its own line of sports nutrition products."
