Keto Info week 1/1

[spEEdfrEEk]

CATEGORY: biology/metabolism

TECHNICAL: ****

SUMMARY:

This document gives the rather technical/intimate

details of how someone who is low-carb and ketogenic can

sustain a weightlifting session and have the energy to do so

start through finish.

It's a pretty rough read for those uninterested in

the biomedicine, so I'll give you the short version here.

Your body accomplishes this task by using the "waste products"

of active muscle exercise: lactate (which gives you that

burning feeling) and pyruvate (another precursor to the

glucose generation process) to synthesize new glucose in the

liver. This new sugar is then sent back into the bloodstream

for use by the active muscle.

It's important to realize that amino acids are part

of this process, so be sure to get enough protein in your

diet as well as fats, or you may risk muscle loss (to the

conversion process).

Incidentally, you will also notice (as I have) that

because of this glucose generation process - if you check for

excess ketones in the urine stream (with ketostix) right after

you train - you'll see that you're temporarily non-ketogenic.

That is why it is a good idea to follow up a weight

lifting session with a little easy, short aerobic work. Cycling,

for example, can more rapidly remove the excess lactate from

the working muscle and convert it back to muscle/liver glycogen.

This not only reduces your post-workout soreness, but

also drops your blood sugar and speeds you back into a ketogenic

state. (and primes your muscles with stored glycogen for the

next lifting session)

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Subject: The anabolic diet...

Date: Sun, 4 Jun 1995 13:22:37 -0500 (CDT)

Hello!

I finally found the answer I was looking for regarding the anabolic

diet. When people (my adv. nutrition teacher, biochemistry professor

etc.) put me on the spot, I have reluctantly explained the diet based

upon the manuals findings, which I explained were not technical enough,

and had real difficulty convincing them. But now I finally found an

answer that is technical enough, and explains the reasoning behind this

ever so commonly asked question; "since weight training is anaerobic,

where is your energy going to come from when you don't consume enough

carbs, since glycolysis is the major pathway involved in anaerobic

exercise?". Well I finally struck pay dirt. It took an inordinate

amount of time, too much time in fact, and I am going to call Optimum

Training Systems and request that they revise the manual or add an

addendum in which this is explained more in depth. Like I said, you are

going to be hard pressed when someone in the know starts battering away

with technical questions, that the diet doesn't provide. Sure the manual

tells you that dietary and body fat will be the fuel for your workouts

along with the creatine from the red meat, but that doesn't cut it. Which

finally leads me to this answer.

Since anaerobic wt. training HAS to go through glycolysis, I thought

that readdressing that pathway might lead me to an answer, and it did. As

you know the 2 hormones insulin and glucagon work together, when carbs

are present, insulin secretion from the pancreas increases, and times

when carbs are low, glucagon secretion increases to supply carbs for

energy. When going through glycolysis there are 3 regulatory steps, one

of them involves the enzyme PFK-1 (phospofructokinase-1). It is one of

the reactions that are catalyzed early in glycolysis, the third step If I

recall correctly. Anyway, it seems that this enzyme PFK-1 is sensitive

to levels of carbs in the blood. When carbs are low, as in the diet,

glucagon is going to be chronically activated, which in turn will

influence the enzyme PFK-1. When this happens, it tells the metabolic

pathway that glucose just is not available, and therefore the reaction of

glycolysis can not proceed in the normal fashion. THat is why it is a

regulatory step. When this happens, glycolysis basically skips all the

normal steps and proceeds to the end where pyruvate is formed. From

there pyruvate can be converted (broken down) to lactate. Once lactate

is formed from a reaction catalyzed be lactate dehydrogenase, lactate has

no other metabolic fate than reconversion to pyruvate. Hence, lactate is

commonly considered a metabolic dead end. Since lactate formation

catalyzed by lactate dehydrogenase regenerates NAD+ from NADH, the

pathway of glycolysis is complete, with NAD+ becoming available for

glyceraldehyde 3 phosphate dehydrogenase reaction. Thus no net oxidation

or reduction takes place during anaerobic glycolysis to lactate. The

final product, lactate in glycolysis generates 2 mol ATP per mol of

glucose consumed. Oxygen is not required in either case. In most cells,

the majority of ATP is produced by oxidative phosphorylation, which is

strictly an oxygen dependent process. Yet, in the cornea of the eye, for

example, oxygen availability is limited by poor blood circulation.

Anaerobic glycolysis meets the need for ATP in the abscence of sufficient

oxygen for oxidative phosphorylation. When skeletal muscle is active,

lactate and pyruvate are transported out of the muscle cells and carried

via the circulatory system to the liver where lactate is converted to

pyruvate by the action of hepatic lactate dehydrognease. Pyruvate can be

further metabolized in various ways by the liver: a fraction of it is

aerobically oxidized to Co2 via the Krebs cycle (citric acid cycle), and

some of it is transaminated to alanine, which is used in protein

synthesis. Pyruvate in liver cells can also be converted back to free

glucose by gluconeogenesis. Liver is the principal organ responsible for

regulating the supply of blood glucose to other cells of the body,

including skeletal muscle cells. Thus, a portion of the metabolic burden

of muscular contraction is borne by the liver, which metabolizes the

by-products of muscle activity (lactate and pyruvate) and synthesizes

blood glucose. This inter-organ metabolism, in which liver receives

lactate and pyruvate and furnishes glucose for skeletal muscle, where

glucose is glycolytically metabolized to generate ATP, is referred to as

the Cori Cycle.

Hope this reaches all the doubters out there who were not convinced

the first time! Thanks!

Jeffrey P. Krabbe

Pre-Dietetics, Senior

University of Nebraska, Lincoln

:cool: TJ :cool: