race hydration (Page 2)

Erik,

The article in the Globe and Mail stated that "currently, the government isn't taking action against low-risk natural health products that are sold before receiving approval." It is likely that HEED has fallen into this catagory and that it has not been specifically approved. I don't know what Health Canada's defination of a natural health product is, but it seems odd that a sports drink fits in there.

Hammer's assertion that the big food processors are keeping stevia out of the market seems pretty silly when food processors like PepsiCo, Coke and Cargill are actively trying to synthesize new sweeteners from stevia and bring them to market.

Ok Seriously Followed this all day yesterday and I am flabbergasted at most of this.

Stevia is something I have used as a diabetic for a while and I think most educated diabetics can talk about it better then some weird generic statements I have read here. I will take it as a plant biproduct over aspartame any day.

Second Stevia is expensive that is why large companies don't WANT to use it in the manor most do now. Line it up next to other sweetners price wise and you will see. The US offers diet coke with Splenda now (not in Canada) but it is more expensive. I jump the boarder and buy a few cases myself to cover my overwhelming desire for a cold diet coke after a long bike ride or a long hot run. But general public doesn't want to pay more for a diet coke with splenda in a store next to the regular coke.

Lastly if I suffered that much issue from mixing different products and my guts couldn't handle things I would just find a way to supplement my own race. Asking for standardization amoung all races is just blasphemy it won't happen and race directors have enough work on their hands and costs to deal with. They all pick the best viable option they can for what they see fit.

But every race I have done(not many mind you) does have WATER on the course. If you struggle that much why make this so freaking complex. People naturally add too much complexity to problems. The key here is you have issues, you must solve those issues. Pleading to the general public isn't going to help you solve your problem. That is specific to you and you only. Too an extent. Some of us suffer similar things.

But you are not going to show up to a race and when you get to the first Aid Station have a fountain dispenser of HEED, GATORADE, INFINTE, POWERBAR and you get to choose. This isn't Taco Bell fountain dispensing. If a race director asked 10 people what they would like for a sports drink at a race he would have 10 different drinks to supply.

I learned my lesson last year at the Detroit Half Marathon that I trained using Gatorade and had no issues, but I kept it a bit on the weak side. They mixed it strong and it didn't sit well with me. You know at the 17th km when I cramped I didn't get mad at the race director.

I evaluated my situation and formulated my plan for next year before I even finished the race. I will use my normal product Mixed very strong in a hand held bottle and I will mix it with water at aid stations. I will solve my own problem instead of training with multiple products. Because only I can fix or deal with me. I am doing REV3 in Cedar point and I can't get my hands on Gatorade Endurance over here. I MAY try it so I don't have to carry stuff. But likely I will supply myself because I have some special needs for fueling.

If you think just upset guts are troublesome. Trying being a diabetic and fueling. Thanks to Triathlon and weight loss I am no longer on medication. But I am still insulin resistant and I still need to watch my fueling. Too much carbs and sugars and I get tired from an insulin spike.

I do not want to get into another back and forth and have to say I think the last post by Chris is spot on. In the end I think you should train with what works best for you and then use that nutrition on race day. If it is not provided by the race then bring it with you.

I am posting because, as I promised, I have spoken with Hammer and provide the following information which is directly from them. I know how passionate the key people at Hammer are about providing the best product possible and I will go on record as saying I honestly don't believe this is marketing propaganda. My contact spent a great deal of time compiling the following information specifically for this forum and thread, so please look at this with an open mind. (You might also like to know he is a multi-time ultra-endurance cyclist including multiple RAAM's.

Finally, Hammer is not trying to sell you anything here, they are trying to answer your question/concerns. Whether you decide to use the product or not is your choice. You will note that they articulate that sentiment at the end of this post.

Here is a cut and paste from today's correspondence with Hammer.

There will be two posts to accommodate all of the information.

Start of message:

I want to say that I totally agree with you that, given the choice, in a race I would carry the fuel that has proven to work for me via testing in training, rather than put my race in jeopardy by relying on the offerings at the aid station. "Go with what got you there in the first place" has always been my motto when it comes to fueling for my longer-duration cycling events (ones that had aid stations).

Secondly, I believe that it's important that all athletes test a number of fuels in their training, under a variety of conditions, so that they can find what works best for their personal physiology. As one of my articles states: "Proper fueling of the body prior to, during, and after exercise requires personal experimentation to find the ideal fit for you, the individual athlete. There is no 'one size fits all' approach; we are all 'experiments of one' when it comes to fueling during exercise. You need to determine, through trial and error in your training, what works best for you."

With that in mind, here is our position on why we use complex carbohydrates instead of simple sugars or a combination of simple sugars and complex carbohydrates. In this "statement," as well as in the attached links, you will find research references...

Simple sugars (one- or two-chain sugars such as glucose and sucrose), when mixed at solutions no more concentrated than 6-8%, will empty the stomach at the same rate as normal body fluids. The reason for this is because, at this concentration, they match body fluid osmolality parameters (280-303 mOsm). Complex carbohydrates (such as maltodextrin), a long chain of repeating glucose molecules connected together, may be mixed in more calorically dense solutions (generally around 15-18%), and even at this seemingly high concentration the mixture will still match body fluid osmolality parameters and exit the GI tract at the same rate as bodily fluids.

In his article, "Osmolality Review: The Biochemistry of Fuels Absorption," (http://www.hammernutrition.com/knowledge/osmolality-review-the-biochemistry-of-fuels-absorption.297.html), Dr. Bill Misner writes:

"Simple-sugar solutions at body fluid osmolality levels are slowly absorbed at the rate of 6-8% maximum due to employing fructose or sucrose for sweetening. Simple sugars dramatically resist gastric transition when internal body temperatures rise proportionate to time, intensity of pace, duration, fluid and electrolyte losses. Such increases from body fluid and electrolyte depletion may permit only 3-5% sugar solutions to absorb in most athletes, before stomach upset, cramping, or muscle failure occurs. When a solution containing simple sugars is added to one containing complex carbohydrates, osmolality may double, imposing gastric stress during endurance events." (STEVE'S NOTE: This is why we do not buy into the "multiple carbohydrate sources are better than complex carbohydrates" argument)

"The structure of glycogen based on its amylopectin to amylose ratio has no duplicate-equal in the human food chain. The potato's amylopectin to amylose ratio is similar; however, with long chain maltodextrin a close second. The glycemic index of maltodextrin is actually several points higher than high glycemic simple sugars. That said, we do not recommend high glycemic index fuels except during exercise in which they are depleted faster than they can be lost. Maltodextrin can be consumed at a higher rate (15-18% solutions) than simple high glycemic sugars (6-8% solutions) due to the extraordinary osmolar pressures produced in the human gut by short chain simple sugars. When osomality goes above 303 or below 280 mOsm, the gut must pull minerals and fluids out of the serum circulates to mediate a narrow 280-303 mOsm range for immediate calorie absorption."

In other words, complex carbohydrates allow for up to three times more calories to be efficiently absorbed as compared to simple sugars. Why? Because their osmolality matches body fluid osmolality parameters even in calorie-dense, seemingly high 15-18% concentrations. On the other hand, simple sugar fuels match body fluid osmolality only when mixed at calorically weak 6-8% solutions.

REFERENCES:

1: Moodley D, Noakes TD, Bosch AN, Hawley JA, Schall R, Dennis SC.
Oxidation of exogenous carbohydrate during prolonged exercise: the
effects of the carbohydrate type and its concentration. Eur J Appl
Physiol Occup Physiol. 1992;64(4):328-34. PMID: 1592058 [PubMed -
indexed for MEDLINE]

2: Hawley JA, Dennis SC, Nowitz A, Brouns F, Noakes TD. Exogenous
carbohydrate oxidation from maltose and glucose ingested during
prolonged exercise. Eur J Appl Physiol Occup Physiol. 1992;64(6):523-7.
PMID: 1618190 [PubMed - indexed for MEDLINE]

3: Hawley JA, Dennis SC, Laidler BJ, Bosch AN, Noakes TD, Brouns F. High
rates of exogenous carbohydrate oxidation from starch ingested during
prolonged exercise. J Appl Physiol. 1991 Nov;71(5):1801-6. PMID: 1761477
[PubMed - indexed for MEDLINE]

--- END ---

The article "CALORIC INTAKE - Proper amounts during endurance exercise" is one of the articles in The Endurance Athlete's Guide to Success (http://www.hammernutrition.com/downloads/fuelinghandbook.pdf) and I would encourage athletes to read this article as it contains a lot of information regarding our position on what constitutes proper fueling during exercise. 

Not included in that article (due to limited space), is some research that we believe shows the superiority of complex carbohydrates as compared to simple sugars. I've attached that as a WORD doc for you.

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DaveH posted the following: "I had a look at the Hammer website and looked at the ingredients for HEED. I got as far as xylitol and stevia before I stopped reading. Why on earth would they put xylitol and stevia in a sports drink? Xylitol and other sugar alcohol sweeteners are well known to cause gastrointestinal side effects such as diarrhea, bloating, and gas, which is already an issue for me. Stevia was labelled by the FDA and the EU as an unsafe food additive for years, and is just starting to become used. Industry has been lobbying hard for it's use in things like zero calorie soft drinks, which makes some sense for a zero calorie beverage, but why mess with zero calorie sweeteners in sports drinks where consuming calories is the main point? I assume that HEED is using maltodextrin as a source of calories, but it seems very odd to use questionable sweetners like xylitol and stevia instead of just putting some sugar in. Some of the research on stevia was done here, but my understanding is that it is not grown or processed in North America and just shipped in from China as a powder."

Here is my response to those comments, some of it courtesy of information I have on file from Dr. Misner:

1) Xylitol is used in HEED for several reasons; however it is not a major caloric donor. 

Gastric stress disorders potentially present when too much carbohydrate solution, too little fluid, fluid loss, microbial source gut flora contamination, electrolyte imbalance, electrolyte overdose, or electrolyte underdose. Xylitol, like most sugar alcohols, can have a mild laxative effect at high doses. It has no known toxicity, though; people have consumed as much as 400 grams daily for long periods with no ill effects. Generally, xylitol-induced gastric stress occurs as a laxative effect in people who are sensitive to xylitol consuming 30 grams in a single dose or multiple doses in a short period of time. Every scoop of HEED contains only 1.78 grams xylitol. The human body naturally produces over 15 grams of Xylitol every day by way of normal metabolic processes. Xylitol is formed when the carbonyl group of Xylose is "reduced." Xylitol is a type of 5-carbon sugar alcohol (polyhydric alcohol). Unlike most carbohydrates, xylitol does not increase blood sugar levels. You get the sweet flavor taste with only small amounts of this sugar alcohol, which is just enough to balance calcium uptake for teeth, bones, and losses in blood calcium during exercise.

Other information regarding xylitol: 

http://www.vrp.com/xylitol/natural-sugar-substitute-supports-oral-health
http://www.vrp.com/heart-health/oral-health-and-heart-disease-the-unexpected-connection
http://www.vrp.com/xylitol/xylitol-sweetener-may-support-bone-health

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2) Regarding stevia, Dr. Nancy Appleton writes:

We always asked about sweeteners since we really don’t like sugar. Our answer is always we give limited support to Stevia and nothing else. We tell people who are healthy and still can walk away from the hot fudge sundae that Stevia is much better for you than sugar, fructose, high fructose corn syrup and the whole list of sugar alcohols and products of “Better Living Through Chemistry” that appear as multicolored packets on the restaurant table. We tell sick or addicted people to break the active phase of their sugar addiction and heal awhile before switching to Stevia.
Stevia, a plant-extract originally from Central and South America has been used as a sweetener for several centuries. It has been described alternately as either 30 or 300 times as sweet as sugar. Stevia has slowly gained popularity as an alternative to sugar, even though it wasn’t marketed, until recently, in the U.S. as a sweetener, but a dietary supplement. We can thank the FDA for this bit of Orwellian Newspeak. A food or drug is either safe or it is not.

As of September 2009, the Food and Drug Administration has given support to two Stevia products, Truvia and Purevia, for use as a sweetener in sodas and other drinks. Approval of Stevia as a food sweetener is still pending, but once the camel’s nose is in the tent things will happen automatically. What changed for a government organization that used a 1985 study that described Stevia as a mutagenic agent in the liver (possibly carcinogenic)?
Apparently, Coca-Cola and other large manufacturers of drinks and sodas have twisted some arms of the regulators, because as more people grasp Sugar Bad, Stevia Good Big Soda needs to give the people soda that appears healthy to keep up sales. Trust a corporation to turn something potentially helpful in moderation into something you still shouldn’t consume.

We will point to the “Hard Facts About Soft Drinks” chapter in our latest book, Suicide by Sugar to inform the reader that no soda is safe to drink. The primary culprit after sugar: phosphoric acid. Putting that much phosphorus into your body does as much damage to the Calcium-Phosphorus ratio as we have always said from the beginning of Dr. Appleton’s career. We also described phosphoric acid as an industrial solvent possibly able to clean toilets and kill insects.

Once the soda and juice manufacturers get their products into the marketplace, eventually Truvia will also be stuffed into the rainbow of packets on the table at our favorite eateries. Presently, that rainbow includes White (sugar or sucrose), Blue (aspartame), Pink (saccharin) and Yellow (sucralose). For purely, aesthetic reasons may we suggest Green for Truvia?

However, we will caution readers against these packs because we suspect that the Stevia in the Truvia packs will be mixed with dextrose or maltodextrin as the first ingredient (largest amount) in each pack as is the case with the other colors in the bin. These are sugar derivatives that will adulterate whatever is good and useful about Stevia. Mixing good things with bad things only ruins the food value of the beneficial as we have said many times explaining why many people are allergic to wheat due to a lifetime association with sugar.

So what is so good about Stevia that we actually are cautiously optimistic about the eventual release of small bags of pure Stevia powder in the supermarket for use in baking, coffee, grapefruit and lemonade? Well, despite the ignominious beginning to Stevia as a sweetener, a study that had been described as being “able to classify distilled water as a mutagen” enough people have used the product that there are health studies that show benefits for many diseases.

A study published in 2000 gave stevioside (Stevia’s active ingredient) to 60 hypertension patients with a placebo group of 49. Results described as significant for reducing blood pressure supplemented similar animal studies.
Stevia’s reputed limited effect on blood glucose naturally led to diabetes studies. A Denmark study took blood glucose readings from 12 type-2 diabetes patients before eating Stevia or cornstarch with their meals and a couple hours later. The Stevia group showed blood glucose levels at least 18-percent less than the starch group, leading to the possibility that diabetes patients have finally found the sweetener that will allow them to have their sweet cake and eat it too.[ii]

But, after the FDA has spent many years trying to keep Stevia out of the U.S. marketplace, we should ask if there are any side effects. A study conducted by the Burdock Group generally supports the safety of Stevia, finding no adverse effects in rats at the massive doses such studies use to determine carcinogenic or mutagen properties of foods.[iii]

And so we give Stevia qualified support because while almost no information has surfaced to say that this sweetener hurts people, we realize that the weak link in any health plan is the patient him or herself. Many of us are unlikely to moderate our consumption of Stevia because so far we just have to have ice cream, chocolate cake or soda. Too much of a good thing isn’t good. But, on the range of things that are sweet but not named sugar, Stevia is a great start.

Source: http://nancyappleton.com/2009/11/17/stevia-having-our-cake-and-eating-it-too/

REFERENCES:

Chan, P, et al “A Double-Blind Placebo-Controlled Study of the Effectiveness and Tolerability of Oral Stevioside in Human Hypertension” Br J Clin Pharmacol. 2000 September; 50(3): 215–220. doi: 10.1046/j.1365-2125.2000.00260.x
[ii] Gregersen S, et al. “Antihyperglycemic Effects of  Stevioside in Type-2 Diabetic Subjects.” Metabolism 2004 Jan;53(1):73-76
[iii] Williams LD, Burdock GA “Genotoxicity Studies on a High-Purity Rebauside A Preparation.” Food Chem Toxicol. 2009 Aug;47(8):1831-1836

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Other information regarding stevia:

This from the Life Extension Foundation (http://www.lef.org/magazine/mag2006/jun2006_itn_02.htm#tpmr) - 

The combination of soy protein and stevioside, a derivative of the leaves of the stevia plant (Stevia rebaudiana), may counteract the numerous biochemical manifestations of metabolic syndrome, according to a recent report in the journal Metabolism.*

Afflicting more than 50 million Americans, metabolic syndrome is characterized by insulin resistance, hypertension, elevated triglycerides, and diminished high-density lipoprotein (HDL).

Animal studies have shown that stevioside lowers blood pressure and blood glucose, while soy protein is known for its beneficial effects on cardiovascular disease risk markers in type II diabetes. Stevia leaf is a calorie-free natural sweetener. Danish researchers sought to determine whether the combination of soy protein and stevioside would offer benefits in treating type II diabetes and metabolic syndrome.

In this 10-week study, male diabetic rats were randomly assigned to four groups fed different test diets. The control group received a standard carbohydrate-rich chow diet, while the other groups received either standard chow plus stevioside, half chow and half soy protein, or half chow and half soy protein plus stevioside. Each week, the researchers measured plasma glucose, blood pressure, weight, and food intake in the test subjects.

After two weeks of treatment, the stevioside-supplemented rats demonstrated reductions in systolic blood pressure and blood glucose levels. The rats supplemented with soy protein demonstrated reductions in total cholesterol, triglycerides, and free fatty acids.

The researchers concluded, “The combination of stevioside and soy supplementation appears to possess the potential as an effective treatment of a number of the characteristic features of the metabolic syndrome.”

—Christie C. Yerby, ND

REFERENCE: 

* Dyrskog SE, Jeppesen PB, Colombo M, Abudula R, Hermansen K. Preventative effects of a soy-based diet supplemented with stevioside on the development of the metabolic syndrome and type 2 diabetes in Zucker diabetic fatty rats. Metabolism. 2005 Sept;54(9):1181-8.

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Dr. Gordon Reynolds, in a portion of an interview (http://www.lef.org/magazine/mag2005/feb2005_profile_reynolds_01.htm), the following was written: 

While he spends most of his time focusing on positive things people can do, Dr. Reynolds reserves harsh criticism for the food industry and its efforts to market processed food products at any cost.

“Sugar is an addictive taste, and the food companies know it,” he says. “Unfortunately, we begin reinforcing it as a reward for children, and now it’s stuffed into pretty much everything.”

While refined sugar is the main culprit, he expands the definition to include other simple carbohydrates, like processed white flour and corn syrup. Moreover, even many “sugar-free” products contain sweeteners that he says are dangerous, including aspartame. His concern with these products is simple: by flooding our systems with simple sugar, we wreak havoc with insulin response and promote obesity. Much of that simple sugar is converted into fat, while wildly fluctuating insulin levels are associated with diabetes.

Instead, Dr. Reynolds recommends a diet of whole grains and whole foods, saying, “A lot of people rarely come into contact with anything whole.”

If sweetening is necessary, he recommends stevia, an herb that is many times sweeter than sugar, or xylitol, a sweetener with some crucial advantages.

“We use xylitol almost exclusively,” he says. “It’s found in the body in small amounts and in nature. It doesn’t increase insulin levels, and some of its calories are never absorbed because it feeds the good bacteria in the colon.

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http://stason.org/articles/wellbeing/health/Stevia-The-Sweetest-Substance-on-Earth.html 
http://www.organicconsumers.org/articles/article_7140.cfm
http://www.stevia.net/safety.htm
http://www.raysahelian.com/stevia.html
http://www.hammernutrition.com/hnt/14588/ - This is an FAQ on our site entitled ""Is the amount of stevia used in your products safe?" 

Some extremely interesting and eye-opening information about Truvia and Purevia, including what they’re comprised of and how they are different than stevia, can be found at the following links:

http://nutritionwonderland.com/2009/02/truvia-purevia-past-future/
http://nutritionwonderland.com/2009/02/stevia-controversy/
http://nutritionwonderland.com/2009/02/science-truvia-and-purevia-rebiana/

I would suggest that readers review all of this information before passing judgment on stevia. If, after reading this information they are still convinced that stevia is an unhealthy substance, that's their prerogative. But to condemn our use of stevia (and xylitol) in some of our fuels without having a balanced view of the wealth of information available, is akin to being an ostrich with their head in the sand. By the way, in one serving (1 scoop of HEED) there is a mere 55-59 mg of stevia. In one of the links I provided above (http://www.hammernutrition.com/hnt/14588/), note that the LD50 for stevioside is a whopping 15.0 grams/kilogram. For a 165-lb/75-kg athlete that translates to 1125 grams (1,125,000 mg) of steviosides. Considering the safety record of stevia, plus the fact that its LD50 is 5x higher than salt, and even higher than vitamin C, the tincture of stevioside formulated in some of the Hammer Nutrition products should not be of any concern. 

FINAL COMMENT: We believe that maltodextrin is the ideal carbohydrate source as compared to simple sugars... the attached document, as well as Dr. Misner's article listed above ("Osmolality Review: The Biochemistry of Fuels Absorption" - http://www.hammernutrition.com/knowledge/osmolality-review-the-biochemistry-of-fuels-absorption.297.html), provides a wealth of information as to our rationale for using maltodextrin in our fuels. If there is a downside to maltodextrin it is pretty bland tasting. Our original long distance fuel, Sustained Energy, which contains no sweeteners at all, just maltodextrin, is a perfect example of the neutral-to-bland taste of maltodextrin. Some athletes enjoy minimal sweetness in their fuel, which is why we offer Sustained Energy as well as unflavored versions of Hammer Gel, HEED, and Perpetuem (the latter being our other long distance fuel). Both xylitol and stevia are extremely sweet, much more so than, as an example, table sugar (sucrose) so very little is needed to sweeten a fuel. This is but one of many reasons (a lot more are in the articles whose links I've provided) why we believe that xylitol and stevia are significantly better choices - both for athletic performance and general health - compared to refined sugar, high fructose corn syrup, or the plethora of artificial sweeteners. 

As I mentioned earlier, if a person looks at both sides to the "issue" (assuming there really is one to begin with), and still decides that our position/rationale is incongruent with theirs, then they should use whatever product they feel works best for them. It is only via testing in training, with a variety of products, that will ultimately determine what fuel will work best for a particular person and their unique physiology. 

END OF PART 1

Part two:

COMPLEX CARBOHYDRATES - A Superior Fuel Compared to Simple Sugars

Most everyone who is familiar with Hammer Nutrition fuels knows our uncompromising stance on the use of complex carbohydrates versus simple sugars for optimal fuel/energy production. In Endurance News #52 (http://www.hammernutrition.com/downloads/ENews/ENissue52.html) we ran an article (“Complex Carbs or Multiple Carb Sources – Which is Better?&rdquo that discussed the results of research by the Dutch sport scientist, Asker Jeukendrup. To recap the article, the general conclusion of the studies showed that a blend of carbohydrates increased oxidation rates, which means higher amounts of energy were produced. In one of Jeukendrup’s studies he found that cyclists who ingested a 2:1 mixture of maltodextrin and fructose were able to oxidize up to 1.5 grams of carbohydrate every minute. In another study – using a mixture of glucose, fructose, and sucrose – oxidation rates peaked at 1.7 grams per minute. Both those results are pretty eye opening, considering that the majority of research on the subject has shown that complex carbohydrates allowed for 4.0 – 4.1 calories/minute, or approximately 1 gram/minute.

However, there’s more to the results that what first meets the eye and the key to our original article – our position regarding the studies as well as the companies that are jumping on the “multiple carb sources are better than complex carbs alone” bandwagon – was not to dispute the results of Jeukendrup’s published studies. The key to the article was whether or not the results of these studies would be applicable in faster-paced, longer-duration bouts of exercise. You see, if you look carefully at the studies you’ll note that the exercise intensity of the cyclists in the majority of studies was quite low, only 50-55% maximum power output, which I think we’d all agree is very much a recovery pace, if that.

To be blunt, at a leisurely 50% VO2 Max pace, athletes can digest cheeseburgers and pizza with no gastric issues. However, if the heart rate and core temperature is raised even to only 70% VO2 Max, the body must divert core accumulated heat from central to peripheral. This reduces the blood volume available to absorb ingested carbohydrates or whatever the athletes have consumed.

After two decades we have found that in the overwhelming majority of the athletes we’ve worked with – athletes engaged in typical 75-85% efforts and/or in multi-hour endurance events – the combination of simple sugars and long chain carbohydrates, and in amounts higher than 1.0 – 1.1 grams per minute (4.0 – 4.6 calories per minute), have NOT yielded positive results. They did, however, increase performance-inhibiting, stomach-related maladies.

Lowell Greib MSc ND explains that gastric emptying is a key limiting step in carbohydrate metabolism: “If your stomach can't empty the product (no matter what it is) you are going to get nothing from it except a huge gut ache and possibly lots of vomiting! Unless there is new research that I am unaware of, gastric emptying is directly proportional to the osmolality of the solution in the stomach. A long chain carbohydrate (maltodextrin) contributes less to increasing the osmolality than do disaccharides (sucrose, lactose, maltose, etc.).”

 Augmenting Greib’s statements, Dr. Bill Misner writes, “Absorption rate and how fast the liver can ‘kick it out’ are limiting factors. No matter what you eat, how much or how little, the body provides glucose to the bloodstream at a rate of about 1 gram/minute. Putting more calories in than can generate energy taxes gastric venues, electrolyte stores, and fluid levels.”

 Bottom line is not whether or not Jeukendrup’s published studies are disputable, but rather if these studies apply to faster paced, longer duration bouts of exercise. We do not believe this to be the case, which is why we do not recommend the use of multiple carbohydrate sources during exercise. Stick with complex carbohydrate fuels, and we guarantee you’ll see better results.

 With that in mind, here is a portion of research regarding the superiority of complex carbohydrates as compared to simple sugars…

GLUCOSE POLYMERS [MALTODEXTRINS] EMPTY THE STOMACH FASTER THAN SIMPLE SUGARS

BACKGROUND: The energy density of a nutrient drink is one of the main factors that affect the gastric emptying of the solution, while osmolality and viscosity are thought to have only a minimal influence.

METHOD: The rate of gastric emptying of two isoenergetic carbohydrate solutions with different osmolality and viscosity was determined using a double sampling gastric aspiration technique. Six healthy male subjects were studied on two occasions using approximately 550 ml of a solution containing 13.5% of carbohydrate either in the form of a mixture of monomeric glucose and short chain glucose oligomers (G-drink) or of long chain glucose polymers composed of 78% amylopectin and 22% amylose (C-drink).

RESULT: The half emptying time (t(1/2), median and range) for the viscous, markedly hypotonic (62 mosmol/kg) C-drink was faster (17.0 (6.2-31.4) min) than for the moderately hypertonic (336 mosmol/kg) G-drink (32.6 (25.2-40.7) min). The amount (median and range) of carbohydrate delivered to the small intestine was greater during the first 10 min after ingestion of C-drink

(31.8 (15.8-55.9) g) than after ingestion of G-drink (14.3 (6.8-22.2) g). However, there was no difference in the blood glucose (P = 0.73) or serum insulin (P = 0.38) concentration at any time point after ingestion of the two test drinks.

CONCLUSION: The results of this study show that the carbohydrate present in C-drink, although it has the propensity to form a gel, empties from the stomach faster than that of an isoenergetic carbohydrate solution (G-drink) without potentiating increased circulating blood glucose or insulin levels.

 REFERENCE: Improved gastric emptying rate in humans of a unique glucose polymer with gel-forming properties. Leiper JB, Aulin KP, Soderlund K. Sc and J Gastroenterol 2000 Nov;35(11):1143-9.

GASTRIC EMPTYING RATE FAVORS MALTODEXTRINS OVER GLUCOSE 

The high prevalence of gastrointestinal complaints in long-distance runners makes the movements specific to this type of exercise suspected of causing a disruption of normal gastrointestinal function. Gastric emptying rate is one indicator thereof. In the present study trained volunteers performed similar repeated fluid ingestion tests while running and while bicycling for 80 min at 70% VO2max. Control tests at rest were also conducted. Two drinks containing carbohydrate were tested, one hypertonic, and one isotonic. Artificially sweetened water was used as a control.

Gastric emptying rate of the isotonic drink, expressed as a percentage of the volume in the stomach at the beginning of each measurement period, did not differ between cycling and running during the first 40 min and was faster during cycling than during running between 40 and 80 min. With the hypertonic drink no differences between cycling and running were observed. In comparing gastric emptying rates after each sequential bolus, at rest, the isotonic drink was observed to maintain a high emptying rate, equal to that of water, whereas the hypertonic drink emptied more slowly after the first 20-min period. A similar pattern was observed during both running and cycling. The isotonic drink continued to empty quickly after the initial 20 min, whereas GE rate of the hypertonic drink decreased after the initial 20 min.

REFERENCE: Effects of exercise and carbohydrate composition on gastric emptying. Neufer PD, Costill DL, Fink WJ, Kirwan JP, Fielding RA, Flynn MG, Med Sci Sports Exerc 1986 Dec 18:6 658-62. 

CALORIE ABSORPTION RATE IS SUPERIOR USING MALTODEXTRINS 

In four mini pigs a segment of the proximal jejunum was temporarily isolated and perfused with two enteral diets containing isocaloric amounts either of glucose or maltodextrin. With regard to total energy, the diets were composed of 60% carbohydrate, 20% protein and 20% fat. The perfusion rates were 60, 120, 240, 360, and 480 kcal/hour. Absorption of glucose and fat from the maltodextrin diet was significantly greater than from the glucose diet, whereas absorption of protein was only slightly enhanced. A net water absorption occurred at perfusion of the isotonic solution with maltodextrin. Perfusing the hypertonic glucose diet, water was secreted. Therefore the flow rate increased from oligomer to monomer glucose source. With enhanced flow rate sodium secretion increased. However, the sodium concentration of the effluent was determined more by the transepithelial water movement than by the sodium secretion. The present results indicate that in enteral diets with interactions among different nutrients there is a 'kinetic advantage' in glucose absorption from maltodextrin compared to glucose. However, the reduced flow rate of the maltodextrin diet due to the lower osmolality contributed to the enhanced absorption.

REFERENCE: Glucose and maltodextrin in enteral diets have different effects on jejunal absorption of nutrients, sodium and water and on flow rate in mini pigs. Weber E, Ehrlein HJ, DTW Dtsch Tierarztl Wochenschr 1998 Dec 105:12 446-9.

BODY FLUID OSMOLALITY CALORIC VALUES

OF SUGAR AND LONG CHAIN CARBOHYDRATES

Gastric Transit Rates Favor Maltodextrin During Exercise

TYPE OF FUEL               CALORIES PROVIDED AT

   280-303 mOsm. OSMOLALITY

                                       Glucose                                    0.2 cal/ml

                                       Fructose                                    0.2 cal/ml

                                       Sucrose                                    0.4 cal/ml

                                       MALTODEXTRINS                      1.0+ cal/ml

WHEN GLUCOSE CONCENTRATIONS EXCEED 6% GASTRIC STRESS OCCURS [GLUCOSE POLYMERS ABSORBED AT 18%] 

This study compared the effects of ingesting 6% (MC) and 12% (HC) glucose/electrolyte beverages, and a flavored water placebo (P) on markers of fluid absorption, palatability, and physiological function during prolonged intermittent cycling in the heat. On three occasions, 15 trained male cyclists performed two 60 min cycling bouts at 65% VO2max (E1 and E2). A brief exhaustive performance ride (approximately 3 min) was completed after E1 and E2, and after 20 min recovery (P1, P2, P3). Every 20 min, subjects consumed 275 mL of P, MC or HC. The first drink contained 20 mL of D2O, a tracer of fluid entry into blood plasma. Plasma D2O accumulation was slower for HC than for P and MC (P less than 0.001). HC caused more nausea

(P less than 0.01) and fullness (P less than 0.05) than MC or P, and subjects said they would be less likely to consume HC during training or competition (P less than 0.10). Sweat rates, HR, Tre, Tsk, VO2, and PV were similar for all drinks. Performance of P1, P2, P3 were not different among drinks. However, four cyclists failed to maintain the prescribed work rate during E2 for HC but only one failed for MC and P. These data suggest that the slow absorption of a 12% glucose/electrolyte beverage during prolonged intermittent exercise in the heat may increase the risk of gastrointestinal distress and thereby limit performance.

REFERENCE: Effects of ingesting 6% and 12% glucose/electrolyte beverages during prolonged intermittent cycling in the heat. Davis JM, Burgess WA, Slentz CA, Bartoli WP, Pate RR., Eur J Appl Physiol Occup Physiol 1988;57(5):563-9 [Exercise Biochemistry Laboratory, College of Health, University of South Carolina, Columbia 29208.]

GLUCOSE CAUSES GREATER DROP IN BLOOD SUGAR

THAN MALTODEXTRINS

The effects of preexercise hyperinsulinemia on exercising plasma glucose, plasma insulin, and metabolic responses were assessed during 50 min cycling at 62% VO2max. Subjects were fed a 6% sucrose/glucose solution (LCHO) or a 20% maltodextrin/glucose solution (HCHO) to induce changes in plasma insulin. During exercise, subjects assessed perceived nauseousness and light-headedness. By the start of exercise, plasma glucose and plasma insulin had increased. In the LCHO trial, plasma glucose values significantly decreased BELOW the baseline value at 30 min of exercise. However, by 40 min, exercise plasma glucose and insulin values were similar to the baseline value. Exercise plasma glucose and insulin did NOT differ from baseline values in the HCHO trial. Ingestion of LCHO or HCHO was not associated with nausea or lightheadedness. It was concluded that the hyperinsulinemia induced by pre-exercise feedings of CHO did NOT result in frank hypoglycemia or adversely affect sensory or physiological responses during 50 min of moderate-intensity cycling. 

REFERENCE: Glycemic and insulinemic response to preexercise carbohydrate feedings.

Seifert JG, Paul GL, Eddy DE, Murray R, Int J Sport Nutr 1994 Mar 4:1 46-53.

GLYCOGEN ABSORPTION RATE ENHANCED

BY LONGER CHAIN MALTODEXTRINS CARBS

Glycogen deposition in liver and muscle is significantly greater in rats fed a diet containing barley malt extract than in those fed diets containing glucose or starch. We investigated whether particular components of malt extract (glucose oligomers, inorganic salts, protein) were responsible for this effect. Food-deprived rats were fed diets containing carbohydrates of different chain lengths [glucose, maltose, maltodextrins or malt carbohydrates (84-86 g/100 g)] in the presence and absence of inorganic salts (2 g/100 g) and maltodextrin diets(78 g/100 g) containing either no protein or 20 g casein/100 g. Dietary glucose oligomers caused higher blood glucose concentrations than consumption of glucose or maltose but had no significant influence on liver or muscle glycogen. Salt addition resulted in higher muscle glycogen concentrations but had no effect on blood glucose or liver glycogen. Hepatic glycogen concentrations were significantly greater in rats fed casein compared with those fed no protein. Consumption of malt extract has the following advantages over consumption of diets containing glucose or maltose: 1-better glucose absorption related to the presence of glucose oligomers, 2-greater hepatic glycogen concentrations associated with the protein in malt extract, and 3-greater glycogen concentrations in muscle due to the presence of inorganic salts.

REFERENCE: Dietary components of malt extract such as maltodextrins, proteins and inorganic salts have distinct effects on glucose uptake and glycogen concentrations in rats. Flückiger-Isler R, Mörikofer-Zwez S, Kahn JM, Walter P, J Nutr 1994 Sep 124:9 1647-53.

CONCLUSION

 The mechanisms favoring an isotonic solution of 15-18% glucose polymers/maltodextrins enhanced with electrolytes—so as to prevent negative hypertonic solution influence—appear obvious from the literature reviewed. Since it has been observed that simple sugar solutions elevate osmolar pressures above body fluid levels [280-303 mOsm] significantly, their inefficient absorption rate occurs in endurance events where an athlete consumes too much volume or concentrated (> 8%) simple-sugared solution in order to resolve thirst, fatigue, or electrolyte depletion. While the same negative events may potentially occur when too much glucose polymer [complex carbohydrate] solution is ingested, it appears less likely simply due to the favorable isotonic properties of long chain carbohydrates, which again are absorbed immediately in solution concentrations of 15-18%.

End of message.

In Summary, I would like to thank Hammer for taking the time to provide all of the above. I am not sure how many other companies would go to the trouble. As I and others have said, I think you should train with what works best for you and use it on race day. It is what I believe and have practiced personally in all of my Ironman and Iron Distance races. Some have ended up on the podium and a few have ended up in the ambulance with a DNF. Those DNF's were sometimes gastro shutdown issues which I believe were caused by other circumstances such as heat, cold or stupid decisions on my part during the race. However, I always knew one thing going into the race, I had the right nutrition with me because I had trained with it for eight months. 

John,

Just about your entire wall of words was about the advantages of complex carbohydrates like maltodextrin as an energy source in a sports drink instead of simple sugar. As I said before, I understand this. My question was about stevia and xylitol. I did not see anything in your post about the regulatory status of stevia in Canada.

The best point in the Hammer post is that processed foods are bad for you, which is about the best nutrition advice you can get. It was also very useful to learn that Hammer has products with just maltodextrin and no sugar, stevia, or xylitol. These sound like excellent products.

Lets agree to disagree about sweeteners and move on.

Dave,

I have nothing to agree or disagree about.

You asked why they use these ingredients and they answered your question. I took the time to ask and then pass on the information that was provided to me. 

I can only assume that you appreciate it, you are welcome.

I'm actually learning a lot here.  Please don't let it die!

This thread is very informative and I appreciate the time that the people involved have put into researching and backing up their posts with data and the effort that has gone into contacting the various organizations/companies involved.  

I have used HEED and thought it to be a good product and liked that it was some what mild in flavor.  Probably the only reason I dont train with it regularly is that it is less available and more expensive that the 'sports drinks' I can get at the variety store on my way to a workout.  I have trained with whatever I can grab and fuel with a variety of different drinks and products, I consider HEED to be a 'high end' product.  As an amateur athlete this variety has never been an issue for me and I suspect that most of the athletes that do the races in question are age groupers who do not have the specific specialized fueling needs of a more advanced athlete.  I sure dont recall seeing people puking up HEED at any or the races I have done.  By having these different products at the different races these individuals are being exposed to products the may not have otherwise tried, a good move on the part of the companies involved IMHO.

I have serious doubts as to the idea that HEED is a harmful product. Attacking it based on a technicality, the idea that one of the ingredients (stevia) may be suspect for a specific use or its not on a certain list seems a little odd.  I can go down to the grocery store and buy as much Stevia as I want and put it in what ever I want.  There is indeed a bureaucracy preventing the wide spread use of Stevia in Canada based on a flawed research study done in 1985 and a lack of popularity of the product in the past.  I also have severe doubts that John Salt and MSC would have a sponsor for their race series and/or serve a product that was unsafe or questionable.  Triathlon is a relevantly small sport and community, if a product like HEED was harmful, if using it caused health problems and it was hurting people, dont you think that would be common knowledge and that this product would be gone by now,  dont you think MSC would have dropped them and sought Powerade (Coke instead of the Pepsi owned Gatorade sponsoring the Trisportcanada series).  

Personally I like the idea that not both of the major race series in Ontario are sponsored (then owned?) by these uber large world dominating corporations.  I like that there is still a series that supports the smaller companies, the companies that have done so much for endurance sports and have their roots in such. I like that I get to try new products and I like being exposed to aspects of the sport that I wouldnt be exposed to without going and doing races.  Thats part of why I do these races, its part of the experience.

So I guess like it has been said before, if your nutritional needs are so specific that you can not just use what ever is offered on the race course, then your only option is to carry all your own nutrition, otherwise you are going to limit yourself and not experience some really good race venues.  

Jamie,

Thank you for the kind and supportive words regarding our series and the manner in which we make sure we are doing the best for our customers. All I can say is I agree with you about our standards and the sponsors we work with. 

I can also tell you that Hammer has told me they have the green light for H.E.E.D. from Health Canada, no matter what the speculation may be.

Dave, please move on and use water for your nutrition. If you're not happy with what John is providing, or other Triathlon series, or other triathlon races are providing, then provide your own nutrition or move on...

John, thanks for your work, thanks for providing such a great serie, and THANKS for trying to solve problems unsolvable...

We all know what is provided on the triathlon races, we all know it could cause GI issue, WE ALL LIVE WITH IT... That's part of the challenge, that's part of the race.

I'm racing with HEED, Ironman Perform, Powerbar gels, GU gels, etc. I don't like HEED perform, I take water and prepare my own formula. I don't like powerbar gels, I use and carry GU. I live with it like all other athletes on the field.

If you have an issue with a product, contact them directly or Health Canada, or whatever agency you want to waist time with...

We're all gonna go on the other side of the fence anyway, just by breathing the chemical that are in the air... Guess what's happening when you run with a car exhaust is close to your fully open lungs... so just learn to live with...

End of the rant... go back to training...

+1. It's not rocket science. Either work with it or bring your own beer.