Sucrose Is Not a Human Fuel
sucrose is not a fuel
or a carbohydrate ... it is a poison !
from The Oxford Dictionary
poison . n. 1 substance causing an organism death or injury, especially in a small quantity. v.tr.1 administer poison to . 2 kill, injure, or infect with poison.
carbohydrate. n. Biochem. energy-producing organic compound containing carbon, hydrogen, and oxygen, e.g., starch, glucose, and other sugars.
question number one
If sucrose (fructose and glucose hooked together by an O-glycosidic linkage) is composed of carbon, hydrogen and oxygen why is it not considered carbohydrate?
question number two ... "sweet hazard"
Ingesting large amounts of glucose (or other sugars) before a marathon might seem to be a good way of increasing the fuel stores. However, experienced runners (and triathletes) do not ingest glucose (or other sugars) before a race. What is the biochemical reason for their avoidance of this potential fuel? [hint: consider the effect of glucose on the level of insulin.] (the answers are at the end of this page)
the dangers of sports nutrition ... part 8000
Unfortunately, I stumbled onto part one of "The Science of Race Fueling" by Stan Down, in the only other Triathlete magazine around here. Having read part two before part one I can only say that it is even more astounding than part two. Across from the article is a nearly full page photo of pro-triathlete Oscar Galindez sitting on the pavement. The caption on the photo reads, " Pro triathlete Oscar Galindez attempts recovery after an under-fueld [sic] race."
a picture worth a thousand words
Let's begin by taking a closer look at the photo. First, Oscar obviously is in reasonably good shape and carries the label of "Pro triathlete." Why is Oscar on the ground? Please note that in between his legs are three white bottle caps and adjacent to his right hip are two empty bottles and he has a third bottle in his hand pouring liquid not only in his mouth but more or less all over his face. I think from that we can safely surmise that the liquid in the bottles is water since most people don't like to pour sugared solutions all over their body; one gets very sticky that way. Oscar appears to be very hot and most likely is very dehydrated. In the background are multiple fans behind the finishing chute. From that we can surmise that he is not very far from aid, or as Mr. Down would have it, he is not very far from "fuel."
At this point it might be helpful to take a look at what established scientists in the field of biochemistry consider fuel for these type events.
| fuel sources for muscle contraction | ||
|---|---|---|
| fuel source | maximal rate of ATP production (mmol/s) | total ~P available (mmol) |
| muscle ATP | 223 | |
| creatine phosphate | 73.3 | 446 |
| muscle glycogen to lactate | 39.1 | 6,700 |
| muscle glycogen to CO2 | 16.7 | 84,000 |
| liver glycogen to CO2 | 6.2 | 19,000 |
| adiipose tissue fatty acids to CO2 | 6.7 | 4,000,000 |
| note: fuel stores are estimated for a 70-kg person having a muscle mass of 28 kg. After E. Hultman and R.C. Harris. In Principles of Exercise Biochemistry,J.R. Poortman's, ed. (Karger, 1988), pp, 78-119. | ||
Briefly looking at the above table one notes that the most abundant source of energy for muscle contraction is the triacylglycerols in the adipose tissue. The only downside is the relatively slow rate at which they can supply ATP. Muscle ATP and ATP created from creatine phosphate can easily support a much faster rate of consumption but unfortunately they are completely exhausted in a few seconds. To effectively run the 100 meter sprint an additional energy source must be utilized. This source is the anaerobic conversion of muscle glycogen to lactate. This can supply 39.1 mmol/s of ATP, as compared to the 73.3 mmol/s generated by creatine phosphate. However, at the completion of the 100 meters, the blood lactate level goes from 1.6 to 8.3 mM and the blood pH goes from 7.42 to 7.24. These circumstances will not be tolerated much longer than 100 meters and cannot be sustained even for a 1000 meter run because of two reasons. First, as noted above, muscle ATP and creatine phosphate are both completely exhausted within a few seconds and second, anaerobic glycolysis cannot persist for two minutes because the supply of NAD+ would be exhausted far sooner. Part of the ATP necessary for the 1000 meter run must come from oxidative phosphorylation, which proceeds at a slower rate than anaerobic glycolysis. This limits the speed at which one can run 1000 meters. The typical velocity of world class sprinters for 100 meters is 10.1 meters/second, compared to 7.6 meters/second for the 1000 meter event. To run a marathon or a multisport event like the Ironman effectively, one has to train his or her metabolism to utilize other fuels. The total body glycogen stores are insufficient to provide the 150 mol of ATP needed to run a fast marathon in two hours and some change, much less a nine hour Ironman. This necessitates ATP production from fatty acids. If, however, all the ATP had to come from fat it would take six hours or so to run a marathon and who knows how long to do the Ironman, because as you can see from the chart, the rate of ATP production from fatty acids is relatively slow, as compared to glycogen. Elite runners or triathletes must teach their bodies to burn both fuels during a marathon or an Ironman, to achieve a world class speed of 5.5 meters/second for the marathon or an eight to ten hour Ironman. How is this accomplished?
"A low blood sugar leads to a high glucagon / insulin ratio, which in turn mobilizes fatty acids from adipose tissue." *
Fatty acid utilization leads to glucose sparing by inhibiting funneling of sugar into the citric acid cycle and oxidative phosphorylation. Additionally, the high glucagon / insulin ratio leads to increased catacholamine production which inhibits glucose uptake by muscle. This has a glucose sparing effect and increases fatty acid utilization by muscle. The simultaneous utilization of both glycogen and fatty acids leads to a higher mean velocity during the marathon (or Ironman) than would be obtained if glycogen were totally depleted before the start of fatty acid oxidation. Also, in a well trained metabolism there will be some glucose left at the end of the race, should one need to pick it up near the finish. Before we leave the world of academic biochemistry I would like to stress that the above comment regarding the glucagon / insulin ratio is probably the most important thing you can learn both for your training and racing.
* from Stryer Fourth Edition Biochemistry ...pp, 770-779
the bonk cycle: simple sugars in leads
to excess insulin which leads to the bonk
Simple sugars consumed before any racing or training event ALWAYS precipitate an insulin response and, as is typical of sucrose or any simple sugar, the insulin response is excessive and soon leads to a low blood sugar or "bonk". What can I say about Oscar or what can Mr. Down say about Oscar? What can anyone say about Oscar? Obviously, he knows that sitting on the pavement is no way to win a triathlon. I don't really think he planned to collapse near the finish line. How did he get to this point? Mr. Down would have you believe that Oscar is out of "fuel". Loosely translated -he bonked. Before I realized that training and racing with any kind of simple sugars for fuel, was sheer insanity, I used to bonk routinely. Two hours into the Tucson Marathon at 20 miles, I bonked. My wife handed me a Pepsi. I went on, ran the last 10k in 38 minutes, last mile in 5:45 and got a PR of 2:45. Those were the days when I trained without sucrose but would drink Pepsi or Gatoraid during an event. So much for the bonk. Let's at this point define the bonk as "hypoglycemia" (low blood sugar). The reason why bonks occur so frequently in the sports nutrition group is that the sugars used in all those poisonous bars, liquids and powders gain access to the blood stream too quickly or molecularly are not easily handled by a pancreatic / insulin system that evolved on whole food for many years well before man, in his ever present quest for the "Holy Grail" came along and removed all the food from the food. I have bonked enough times to understand that once the blood sugar is on its way back up, you feel good again and you don't end up sitting in the finish chute drinking and pouring water all over yourself. In any well-aided race I find it difficult to believe that anyone could really bonk to the point that he or she is sitting on the ground, dazed and confused.
What else could this be?
understanding the difference between the bonk ...
and early hyperosmolar coma / refractory dehydration
What is the differential for Oscar? First let's look at Mr. Down's proposed idea that Oscar had bonked. If this was a classic presentation of hypoglycemia he would respond quickly to some form of sugar that is plentiful in any well aided event. Pepsi and Gatoraid contain large amounts of readily absorbed simple sugars and theoretically Oscar only needed to drink some Pepsi, eat cookies or candy to complete the race easily. He had to have passed the last aid station before the finish line and at that point he could have easily ingested the necessary calories. It is also very unlikely that he bonked this severely in only the last mile of the race. Looking at the photo I don't see any sugared solutions nearby or any candy wrappers or should I say any powerbar wrappers (what's the difference?). It should also be stressed that under no circumstances do I recommend these types of simple sugars except for the rapid reversal of a falling blood sugar which has been caused by the very thing that can restore the blood sugar quickly. In my own experience I have found the potato to be just as quick and effective at reversing a falling blood sugar. It's a vicious cycle that I had to learn the hard way: simple sugars in lead to an excess insulin secretion which soon leads to a rapidly falling blood sugar. Then if one ingests more simple sugars more excessive insulin secretion occurs and the cycle continues. The only way to prevent it is to not eat the simple sugars in the first place and voila -no more bonks!
What are other possibilities?
Oscar could have had an acute myocardial infarction, which is not very likely but possible. He could have had a stroke (cerebrovascular accident), but again this is not likely. Let's now look at another possibility: refractory dehydration with early hyperosmolar coma and metabolic acidosis. For all intents and purposes Oscar had become temporarily diabetic. How could this happen to a pro triathelete?
This is not rocket science here, it is "The Science of Race Fueling" part one by Stan Down.
How could this be? Isn't sports nutrition supposed to be good for your race? It's unfortunately true that a lot of world class triathletes are reading this garbage about sports nutrition in the latest triathlete magazines and are taking it seriously. That is really dangerous. The human body does not like to do extremely demanding races such as any distance triathlon on poison. According to Mr. Down's article one should start loading on this poison disguised as sports nutrition before the race. Once you ingest some of these poisonous / powerbars / gatoraid the gauntlet has been tossed -your own body's insulin vs exogenous poisonous sugars. Your body is soon at WAR with itself and you are funding the king's sugar business on both sides, making the cause the cure.
"During a long-distance event, a good plan isto eat a gel once every 20 minutes."Stan Down page 80 Triathlete August 2000
However, this time we are going to follow Mr. Down's recommendation that we ingest more of this sugar every 20 minutes. Even if sugar were not poisonous how could he make the recommendation of one gel every 20 minutes for everyone, ignoring body size, training, capability of the individual and last but not least the AMBIENT TEMPERATURE OF THE EVENT? By doing this every 20 minutes you will not bonk, even though you have giant excesses of insulin floating in your blood, because by putting more simple sugars in your blood stream your blood sugar level will never get that low. You will just become hyperosmolar due to the large amount of sugar and insulin in your blood. This will be soon followed by severe dehydration as your renal homeostatic mechanisms kick in to try to reduce the osmolality of the blood by removing the excess of ions, causing an obligatory loss of precious intravascular fluid at the same time. (see "Your Stomach Knows Best" for more on renal homeostasis) Maybe some people's kidneys are better at this than others. Maybe some days you get lucky and manage to survive this situation but anytime you do this to yourself you are at risk for sitting on the pavement. If you are lucky, that pavement will be near the finish line and you won't have to crawl far or have part of your small bowel or colon removed.
diabetic coma
Back to Oscar's picture. He is drinking water and he appears to very hot, dehydrated and to some degree obtunded from a hyperosmolar state. Diabetics go into coma for usually one of two reasons. The first is from having excessive serum glucose which is produced by one of two different paths.
high serum glucose caused by
one: defective insulin and / or insulin production / antibodies
two: excessive substrate (glucose)
A defective insulin production system can lead to an elevated blood sugar (type one or juvenile diabetes), or a normal insulin system and excessive substrate (glucose) which is known as type two or adult onset diabetes mellitus, can also lead to an abnormally high serum glucose. Over time the blood sugar level just keeps rising until the patient becomes comatose. The body biochemically responds to this excess of sugar in the blood in one of two ways depending on whether or not the insulin production system is intact, both resulting in coma. If the pancreatic / insulin system is defective as in type one diabetes (juvenile diabetes) the intracellular glucose levels are low while the serum glucose levels are high. This is intracellular starvation and the cellular biochemistry will produce ketones (acetone) that can be smelled on the patient's breath.
The other possibility is when the insulin delivery system is intact but the substrate load is too high as in diabetes type two (adult onset diabetes mellitus). In this case the intracellular glucose levels are high in addition to the high serum glucose levels. The reason for the high intracellular glucose levels are related to the inhibition of glucose glycolysis caused by the fructose short circuiting of normal glycolysis (fructose glycolysis) yielding a state of high energy charge (increased ATP) and metabolic acidosis caused by the unchecked production of lactic acid since fructose can enter glycolysis below the body's homeostatic control point -phosphofructokinase (for more on this see, "The Biochemistry and Human Physiology of Acute and Chronic Sports Nutrition Toxicity," by this author).
low serum glucose
and excessive insulin (usually iatrogenic)
The other way diabetics can become comatose is from too much insulin and too little blood sugar. Lower the blood sugar enough below 40 mg / ml and the patient can become comatose and die. Even though these are two different situations when I was an intern at Indiana Medical Center Hospitals, we treated them both the same. We gave the pre-comatose patients sugar in the form of orange juice and the comatose patients an intravenous concentrated sugar solution. The patients with low blood sugar would usually wake up nearly immediately. The patients with ketotic or non-ketotic hyperosmolar coma would not wake up at all. At that point we treated these patients with insulin and fluid replacement to lower their sugar levels in their blood. This decreased serum osmolality and in time it would return their "hyperosmolar" state to a normal "iso-osmolar" state and the patient would wake up. This however would take several hours, not minutes. The principle behind giving small amounts of sugar was that the administered dose was not large enough to seriously worsen the hyperosmolar state in those patients with too much glucose and not enough insulin, but was large enough to revive the patients who had "hypoglycemia" (low blood sugar) and too much insulin.
take the sugar test
don't be "candyhapped"
How does all this apply to Oscar? If Oscar was truly "under-fueld" [sic] as Mr. Down suggests he would have tossed down some quickly absorbable sugar which is plentiful at these events and gone on his way finishing with no difficulty. No, I don't think poor Oscar was "under-fueld" (misspelled or otherwise). Oscar was "over-fueled." He had a bloodstream full of "sports nutrition" and was in early hyperosmolar coma, severely dehydrated and obtunded, in addition to being out of the race. Perhaps we should rename Mr. Down's article "Acute Induction of Early Hyperosmolar Coma in Triathletes." Next time you are feeling bad either in a race or on a training ride or run, and you are fueling yourself with some form of sports nutrition, take the sugar test. Ingest some readily absorbable calories such as Gatoraid or Powerbars. If you get better you were probably "hypoglycemic" which, however, was probably caused by some sports nutrition consumed earlier. To avoid that just stop any sports nutrition before or during your ride or run.
If, however, you do not get better and possibly get worse -you are hyperosmolar until proven otherwise. At that point you need to drink large quantities of water to dilute both the hyperosmolar fluid in your stomach as well as your blood stream. If you are not too hyperosmolar you may be able to continue and finish your event. If, however, you still feel bad, it would be best just to forget finishing and stop, rest and cool down. Learn from this and next time train your metabolism before your next event and fuel yourself with whole unprocessed complex carbohydrates and water.
the war on the triathletes
making the cure ... the cause
In paragraph one of Mr. Down's article on race "fueling" he tells us that at the 1995 Ironman Paula Newby-Fraser "skipped a few pit stops and ran out of gas on the bell lap." When Paula, who is probably the greatest female triathlete of all time to date, collapses within sight of the finish line -I would definitely look into it. You tell me how anyone with a fraction of the experience and talent of Paula could find herself on the ground at the Ironman. The best female triathlete with years of experience at one of the best aided courses in all of triathlon -this does not make sense. According to Mr. Down she had skipped a few aid stations. So what? No one with her experience and talent should land on the ground just from skipping a few aid stations. If it truly was the bonk (hypoglycemia), she easily could have eaten a wide variety of simple calories at any of the aid stations and finished the race with no difficulty and probably would not have given up one place. I doubt that she was out of calories; au contrare, she was probably just like Oscar: "OVER-FUELED."
This literally is a very ugly war on some very talented people. When early hyperosmolar coma and refractory dehydration leads to a necessary invasion of a triathlete's abdomen for infarcted bowel, this is war, and as with most wars, people are getting hurt. Someone in the king's sugar business is making a lot of money and a lot of triathletes are paying the price with more than just money. As Mr. Down says in this article, "The message is well presented in Powerbar commercials: Don't Bonk." Making the cure -the cause. As the banker in Europe wrote to his son in America, "The best way to make a lot of money is to start a war, and fund both sides."
Paula's coach Paul Huddle should be distressed. He should, as Mr. Down says in his article, still have an "edge" in his voice even after five years. He should not, however, as Mr. Down continues, "kick himself" about this. Paul is kicking the wrong person! He should be kicking Mr. Down and all the other "scientists" and charlatans posing as authorities on nutrition when in reality they are all "hired mouths" of or have "vested" interests in the king's sugar business. (see "History of Sugar" on this site or read "Sugar Blues" by William Dufty)
one cannot train
or race in an insulin state
Onward through the fog, we come to the next startling revelation from Mr. Down that much of your body's fuel is stored as glycogen, some in muscles and some in the liver. Once again we begin to see signs of confusion in Mr. Down's mind. Earlier he talked of fuel as something that can be bought at the candy store like a powerbar. Now, all the sudden we are calling liver and muscle glycogen the same "carbohydrate" as the simple sugars in powerbars. Without going off into a combination of organic chemistry and biochemistry (my first degree was in a combination of organic and biochemistry) I would like to stress that in no way is the molecular structure of liver or muscle glycogen remotely similar to the molecular structure of sucrose and the other poisonous simple sugars contained in all the sports nutrition. The body's enzymatic systems (basic biochemistry) which process any "fuel" must be induced over time in order for the body to be able to process any substance as fuel. It is impossible to just wake up one day and say my body is now going to burn muscle and liver glycogen at a rate fast enough to support a ten hour Ironman or for that matter a three hour marathon. The body just does not work this way. In order to reach that level of glycogen and triacylglycerol (fat) burning metabolism, the METABOLISM must be trained the same way the muscle groups are trained, the same way the heart is trained. The old adage "use it , perfuse it, or lose it " really applies here.
the molecular basis for the old adage
fats burn in the flame of carbohydrates
Probably one of the most important statements that anyone interested in running a good marathon or a good Ironman can ever understand is:
"The acetyl CoA formed in fatty acid oxidationenters the citric acid cycle only if fat andcarbohydrate degradation are appropriately balanced."Stryer Fourth Edition ... Biochemistry ... page 612
You don't have to know the chemical formula for acetyl CoA, you only have to know that it is the product of burning fatty acids that enters the body's final common pathway for oxidation of fuel molecules (energy production) -the citric acid (Kreb's) cycle. For acetyl CoA ( a two carbon moiety) to enter the citric acid cycle it must react with oxaloacetate ( a four carbon moiety) to form a six carbon moiety citrate. The reaction cannot proceed without equal amounts of each. The oxaloacetate must come from pyruvate formed from glycolysis (carbohydrate metabolism). Pyruvate reacts with ATP (for energy for the reaction) CO2 and H2O to form oxaloacetate, ADP, Pi and 2 H+. Thus the molecular basis for the old adage regarding the necessity of carbohydrate metabolism for the burning of fatty acids (triacylglycerols).
fats do NOT burn in the fire
of any recently ingested sugars
Then Mr. Down references fat burning. "Fat burns in a carbohydrate fire, it is often said, and sugars are a necessary component of fat metabolism." Where this comes from I really have no idea. What kind of sugars are we talking about? Once again we see Mr. Down's confusion about sugars, or his intent to confuse the unsuspecting, that the body can utilize true carbohydrate such as a potato in the same way it uses sucrose. From our basic biochemistry discussion at the beginning of this article it is evident that if we ingest simple sugars at the start of our event we will have an insulin response. A high insulin / glucagon ratio blocks mobilization and utilization of fatty acids (triacylglycerols). Fat does NOT burn in any carbohydrate fire of recently ingested sports nutrition sugars.
If, however, we do NOT ingest these noxious substances at the start of our event and go into the event with a high glucagon / insulin ratio we will be able to mobilize and utilize our triacylglycerols (fat) and our muscle and liver glycogen at the same time -is this what Mr. Down means? If so, then why would he recommend we keep our insulin levels high throughout our event by filling our "fuel tanks" with sports nutrition both at the start and regularly during the event? The concept that these molecules are the same and are treated by the body the same is only born of Mr. Down's chemical naivete. Glycogen is a complex polymer of many smaller molecules of glucose, while sucrose is composed of one molecule of fructose attached to one molecule of glucose via an O-glycosidic bond. To propose for one nanosecond that these chemicals which he loosely terms "fuels" are handled by the body in the same way, with the same enzymatic systems requisite for their metabolic breakdown, is sheer biochemical insanity. The real fuel reservoirs of the body, the liver and muscle glycogen and triacylglycerols (fat) cannot be accessed when the body is full of poisonous sports nutrition which blocks the development of the requisite enzymatic pathways needed to effectively burn these sources as fuel for the long haul.
| fuel reserves in a typical 70-kg man | |||
|---|---|---|---|
| Organ | Available energy (kcal) | ||
| glucose or glycogen | triacylglycerols(fat) | mobilizable proteins | |
| blood | 60 | 45 | 0 |
| liver | 400 | 450 | 400 |
| brain | 8 | 0 | 0 |
| muscle | 1200 | 450 | 24000 |
| adipose(fat) | 80 | 135,000 | 40 |
| from Stryer Biochemistry ...page 771 | |||
check out that 135,000 kcal from fat ... without even a "camel's hump"
This same paragraph continues with a brief reference to the fact that the body's cortisol levels increase with exercise which is true. This is followed by a statement to the effect that cortisol is catabolic and it can break tissue, actually muscle. This is true, but not relevant to the Ironman or any other one day event. Muscle breakdown is a protective mechanism of the body to produce glucose for the brain. It does NOT, however occur in a starving person until after the first 24 hours. It is not a significant factor in an Ironman event. The stored fuels of a starving body will suffice to meet caloric needs for one to three months, but its glycogen stores will be exhausted in the first 24 hours. Gluconeogenesis will then start to produce glucose for the brain from amino acids from muscle breakdown. However, after the second or third day, the fuels being used shifts from glucose to fatty acids and ketone bodies. The brain is able to utilize ketone bodies for fuel and by the 40th day of a fast, it can utilize as much as 100 grams of ketone bodies per 24 hours compared to only 40 of glucose during the same period. Muscle breakdown will be high in the second or third day of a fast but drop considerably during a prolonged fast, from 75 grams during the third day to 20 grams on the 40th day. What is truly amazing to me is how long the human body can survive without any calories.
the toxicity of sucrose and sports nutrition
Even more amazing is the well documented fact that you will live longer eating NO calories than if you ate many calories in the form of sucrose. Five shipwrecked sailors with nothing but sugar (sucrose) and rum, who were rescued in nine days, were found severly wasted. This serendipitous experiment was repeated later with dogs (unfortunately). The dogs were fed sucrose and water. They all wasted and died. Quite a testimonial to the toxicity of sucrose. It has long been established that any human is better off to eat nothing, rather than sugar(sucrose). Out of eleven world class cyclists, triathletes and mountain cyclists on Coach Troy's (Troy Jacobson) CycleRobx video, three have been significantly affected by sucrose. Greg Welch now has ventricular tachycardia and has retired from triathlons. Karen Smyers has thyroid cancer. Wendy Ingraham crawled across the finish line in 1997, along with Greg Welch's wife Sian. These are not people in their 50's or 60's. These are young and (should be) healthy world class triathletes. What is wrong with this picture? Maybe the linear correlation of sugar consumption and the incidence of adult onset diabetes mellitus (acute and chronic sugar toxicity), cancer and heart disease? Adding Greg's wife Sian to the eleven in Troy's video yields a one in three or 33% incidence of significant complications from sports nutrition.
gluconeogenesis
Mr. Down next references gluconeogenesis from muscle breakdown, as another source of fuel for the long haul. He suggests that to perform well at any long distance event we should all train and eat like Mr. Down so that we would all be creating maximum muscle destruction each day in order to utilize gluconeogenesis from muscle breakdown as a source of "fuel". I really doubt that if you take this approach that you will even make it to the starting line of any race, much less the Ironman. Strangely enough this statement is followed by the previously mentioned quote from a powerbar commercial: "The message is well presented in Powerbar commercials: Don't Bonk" What does this mean? How does A follow B? Makes one wonder who one of Powerbar's stockholders might be? Gluconeogenesis is a source for the long haul, but not gluconeogenisis from muscle breakdown. More than one substrate can be fed into the gluconeogenesis pathway and fortunately for those interested in triathloning, two of these are lactate and alanine produced by active muscle contraction and erythrocytes. These substrates feed gluconeogenesis during an Ironman event -not muscle breakdown. More confusion for Mr. Down.
the need for caloric replacement in the Ironman
the need for caloric replacement in a six-day bicycle race
In the next dazzling display of enzymatic ignorance Mr. Down tells us that one can "only absorb about 275 calories an hour." He next tells us that the world's greatest triathlete of all time, bar none, Mark Allen can absorb more than 400 to 500 kilocalories per hour. While all of us puny triathletes were trying to absorb miniscule amounts of energy such as .275 kcalories per hour, Mark was absorbing 400 or 500 kcalories per hour. No wonder Mark was the world's greatest triathlete.
Back on the slightly more serious side now, what is Mr. Down talking about absorbing anyway? Poisonous sucrose laden sports nutrition or real, whole unprocessed foods? As a series of one I can tell you that in the 1984 Ironman I made the big mistake of relying on Gatoraid for fuel. By the time I reached T2 I could not only not absorb enough calories to run the marathon well, but I couldn't absorb anything at all since the toxic hypertonic Gatoraid in my stomach had induced a gastric ileus, plus or minus some degree of pylorospasm. I couldn't absorb any calories or anything -my stomach had stopped emptying. I fixed that problem the next year eating only whole unprocessed potato and lettuce sandwiches. My absorption rate was just fine. I had plenty of calories on board to run the whole marathon and never ever gave it a second thought. My stomach never hurt, it never rejected any of the food. I ate when I was hungry and drank as much plain water as I could. How really clever of me to resort to doing the Ironman event on the same food I ate everyday at home, the same food that man evolved on, the same food that the human body is prepared to process and has the necessary biochemistry to effectively maintain my fuel tanks in the full position. As noted elsewhere on this site, we all must remember that towards the end of the nineteenth century, six-day bicycle races were very popular here in America. This was well before the king's sugar business had given birth to a very bad idea -heavily sugared and artificially colored intravenous electrolyte solutions and candy bars promoted as "necessary for any and all athletic events." Thus, the pseudoscience of "sports non-nutrition was born."
ancedotal rubbish
This pathetically dismal display of dangerously deleterious dogma from Mr. Down finally relieves its weary readers of the burden of readership with some ancedotal discussion about salt. Don't get me wrong; a lot can be learned from good ancedotal information, but not this ancedotal information. Basically when dealing with salt homeostatis, the kidneys and adrenals do most of the work for the body, followed by the sweat glands. Within very limited parameters one can adapt, not train, tolerance to heat. There is little if any information to be obtained from whether or not one has salt deposits on their skin or clothing at the end of any event. We all sweat and all sweat will have various amounts of sodium in it. So what? Telling people with salt on their running shorts to take extra salt during an event is pure rubbish. I finish most three-hour runs here in the desert heat with at least four metric tons of salt on my shorts. I only drink water on these runs. I do not ever need supplemental salt other than what I normally put on my organic vegan whole food meals. There is no way to tell anything at all about any person's salt metabolism from the amount of salt residual on their clothing at the end of any event. Trying to determine one's salt requirement from such an unrelated indicator would be like trying to tell how far a car has been driven by looking at the amount of dirt on it. If you are truly concerned about salt, just add some extra salt (preferably North Atlantic Sea Salt) to your meals at home or your whole food meals that you intend to eat while cycling during the long events. Absorbing isolated salt solutions, made even more dangerous by the addtion of poisonous sucrose and simple sugars on race day, can be very tricky. (please see the link on toxic sports nutrition and your stomach)
Getting through the Ironman can be difficult enough on a good day. I really don't think that it is beneficial to try to nourish yourself during that type of an event with any kind of food (fuel) that has to be regulated or scheduled. The human body just doesn't work that way. Keep it simple. Eat what you normally eat and drink water, an abundance of water. Train your metabolism well before the event. Stay far away from any simple or processed sugars that always induce insulin or an excess of insulin to be secreted, necessitating a bonk, starting the whole cycle of bonking lunacy. Best not to start it at all. Avoid racing anyone until you are well into the run. The swim only serves to prevent a mass start on the bike. The bike is more important, probably the most important because you have to preserve your legs for the run. Stay calm on the bike. If you have done it right and can run well, wait at least until sixteen miles into the run to try to pick it up at all. Most of all, have a nice Ironman day.
answer to question one
While sugars such as sucrose (glucose and fructose hooked together) are composed of carbon, hydrogen and oxygen, any combination of fructose and glucose absorbed by the body simultaneously, does not supply usable energy for human locomotion, since fructose "short circuits" glycolysis and immediately sets the energy charge high (increased ATP), increases citrate (citric acid cycle) and produces unchecked lactic acidosis. None of these are what you want at the beginning of any event, much less the Ironman. The first two of these put the body into a state of synthesis of fuels rather than utilization of these fuels needed for a good marathon or Ironman. The third, elevated lactic acid levels, inhibits phosphofructokinase thus blocking glucose glycolysis, as do the other two to some degree also. Continued ingestion of any combination of glucose and fructose together can result in severe lactic acidosis, hyperglycemia and refractory dehydration. When you collapse, hope that it is near the finish line so that you don't have to crawl too far. We have all seen it -from the Ironman to Xterra, never a pleasant sight and I'm sure even less pleasant for these unfortunate victims of the king's sugar business. The glucose portion of sucrose also raises your insulin level additionally blocking access to your real energy stores. Use of sports nutrition on a regular basis in training will effectively "eliminate" your ability to utilize the incredible amount of energy the human body is capable of storing.
answer to question number two
A high blood glucose level would trigger the secretion of insulin, which would stimulate the synthesis of glycogen and triacylglycerols. A high insulin level would impede the mobilization of fuel reserves during the marathon or triathlon.
from: Stryer Fourth Edition Biochemistry ... pp, 784 and 1030
Copyright John Mericle M.D. 2000 all rights reserved
posted by John Mericle M.D. D.A.B.R. @ 5:13 PM
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