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No Sugar Added Experiment – Part 4: Does Sugar Hurt Athletic Performance?

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I’ve covered several of the bigger health issues with sugar consumption, as well as some ways to remove “hidden” sugar from your diet.  Now, I’d like to focus on sugar as it pertains to athletic performance. (Links to prior articles are at bottom of this post)

The big question is: Does Sugar Hurt Athletic Performance?

Well, for the past six weeks I’ve used only Hammer Nutrition products during and after exercise, so I’ve consumed no added/refined sugars during any workout.

Without altering or increasing my training, my performance has been rock solid, even outlasting a few friends that are normally a bit stronger than me.  I’ve had zero bonks and zero gastrointestinal issues (gut cramps, gas, etc.), which I tend to get after consuming most recovery drinks.  Sports drinks haven’t generally given me too many problems, but Sweetie will tell you more often than not I’m complaining of stomach pains about 30 minutes after drinking other recovery drinks…quickly followed  by her complaints about the results of my stomach pains.  She asks why I keep drinking them (duh, ’cause I wanna get fast!).  I get the same problem from a variety of products, not any brand in particular, all of which contain a lot of sugars in some form. Anecdotally, many racers I’ve met over the years have had similar problems.

But this has been fairly unscientific.  And we like science. So, I’ve interviewed Steve Born, one of Hammer Nutrition’s Senior Staff Members and Technical Advisers.  I realize that asking the company that promotes no-added/refined-sugar in their products to explain the benefits may seem biased and promotional, but after reviewing a lot of Hammer’s information, it’s clear that a) they’re very passionate about what they’re doing and b) every claim they make references published science.  That, and after using their products exclusively for the past month and a half, I have to say it seems to work quite well.  To be fair, there is a list of other no-sugar sports nutrition products listed near the end of this post.

If you’re looking for ways to improve your performance, check out the interview, alternatives and more after the break…

Full Disclosure: Hammer Nutrition sent the following products at no charge for me to use during this experiment.  We appreciate the support but made it clear in advance that this experiment is not an explicit endorsement of their or any product in particular.  That said, I couldn’t find any other brand with a full portfolio of endurance-related sports nutrition products that did not have refined or simple sugars.  What I could find is listed further down.


Q: Let’s establish your bonafides…what’s your educational background?
A: Nearly 20 years of independent studying of fueling and supplementation, with over 10 of those years under the tutelage of Dr. Bill Misner, PhD, the now-retired head of Hammer Nutrition’s Research and Development. Additional “in the field” studying (via my athletic career) spanning from 1987 – 2003.

Q. How did you get into this position with Hammer Nutrition?
A: I had been using Hammer Nutrition products for about a decade (I was one of their earliest sponsored athletes) and had been advocating their use in my primary sport of ultra cycling, as well as in my secondary sport of Nordic skiing. Throughout this time I was corresponding frequently with company owner, Brian Frank, so even though we had never formally met, we seemed to know each other fairly well. At a point in my life where I was between jobs I asked Brian if he’d consider hiring me. We had a short interview while he was attending a cycling race in Northern California. Shortly after that I moved from California to Montana, where I’ve been for the past 10 years (I celebrate my 10-year anniversary with the company this April).

Q: In a nutshell, why is sugar bad for athletes in general?
A: Refined sugar (a.k.a. simple sugars) are bad for athletes and non-athletes alike, especially in the amounts we consume on a daily-to-yearly basis. A number of negative health consequences can be correlated to the intake of sugar; in fact, Dr. Nancy Appleton, PhD, a well-known author and expert on the hazards of sugar, has an article that lists 146 reasons why sugar is detrimental to health. The full article, with references can be found at http://www.hammernutrition.com/knowledge/146-reasons-sugar-ruins-your-health.287.html (Full Disclosure: Hammer sells her book and video, too)

Q: More specifically, why is it bad for athletic performance?
A: In simplest terms, simple sugars (glucose, sucrose, etc) have two primary problems: First, they provide only a very short-term energy, followed by a dramatic plunge in energy… this is commonly referred to as a “peak and valley” or “flash and crash” type of energy.

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

(Editor’s Note: Gatorade, as purchased in the c-store, is in that 6% to 8% range.)

Q: Some of the research Hammer cites states that consumption of Maltodextrin, which is the primary carbohydrate source in Hammer’s drink mixes, increases blood glycogen faster than glucose or sucrose. If elevated blood glucose levels are one of the primary health issues of excess sugar consumption, why wouldn’t this be just as bad for our body?
A: During exercise, and immediately following exercise (for glycogen replenishment purposes), a high-glycemic index carbohydrate source – which would cause a rapid rise in blood sugar levels – is a desirable effect. At all other times, a moderate-to-low glycemic index carbohydrate source is recommended.

The beauty of complex carbs (maltodextrin) is that they will match body fluid osmolality, not at a 6-8% solution, but a more concentrated 15-18% solution. Even at this seemingly too-high concentration complex carbohydrates (such as maltodextrins/glucose polymers) will empty the stomach at the same efficient rate as normal body fluids and provide substantially more calories (up to three times more) than simple sugar mixtures will. In addition, the energy provided by complex carbohydrates is longer lasting and more consistent than what is provided from simple sugars. To use an analogy, using simple sugars to fuel the body is similar to lighting a piece of paper on fire – yes, you do get some heat but it’s a very short-term heat (energy)… it burns quick, hot, then is out. Complex carbohydrates, however, are kind of like putting a log in the fireplace. You get a longer lasting supply of heat (energy) and when the heat (energy) does die down, the declination is much more subtle and gradual.

Q: Some of your products (Hammer Gel, HEED, Perpetuem, Recoverite) contain 2g to 7g of sugar per serving. Where does this come from, the fruit juice concentrates and Energy Smart (a third-party patented blend of fruit juice and grain dextrins)?
A: A fractional amount of the sugar in the Hammer Nutrition fuels does come from the Energy Smart and/or fruit juice components. However, the majority of it comes as part of the naturally-occurring “matrix” of the 5-chain complex carbohydrate. In other words, as part of its whole, a small percentage of the complex carbohydrate source is naturally made up of one- or two-chain carbohydrates, which are listed as sugars. A similar way of looking at it is when you consider what is arguably one of the healthiest fats that can be consumed – flax seed oil. However, though the majority of its makeup is in the form of healthy fats, a small percentage of its makeup is in the form of saturated (a.k.a. “bad”) fats. This is simply a part of the natural makeup of flax seed oil; it naturally contains a small percentage of saturated fat. The same analogy is true with complex carbohydrates – as part of their makeup, a small portion is comprised of one- or two-chain sugars.

Q: How does this amount of sugar affect athletic performance?
A: It doesn’t affect athletic performance negatively. Because the small amount of sugar in Hammer Nutrition fuels is “part of the whole” the body responds much more favorably than if a simple sugar fraction, such as glucose or sucrose, is added as a separate entity to a fuel mixture.

Q: Using the Almond Raisin flavor as an example, Hammer Bars have 15g of sugar, albeit from natural sources, including dates, raisins and agave nectar. These contribute more than 60% of the total carbs as sugar (but only about 27% of total calories), and the other flavors have more total sugar. In terms of how the body sees and reacts to sugar, what’s the difference whether you’re getting it from fruit/vegetable sources or just syrups and sugars…especially when it’s combined with other foods, proteins and fats?
A: Similar to the previous question and answer, when the fruit sugar is part of the whole (as it is in dates, raisins, other fruits, and other vegetables), the body responds much more favorably than when it (the fruit sugar) is taken out of the fruit or vegetable, processed, and added as a separate ingredient to an energy fuel. In other words, and as an example, the body responds much more favorably to the fruit sugar when it’s in the banana – with all its enzymes, fibers, and other components – than when the fruit sugar is extracted, processed, and put into an energy fuel as an isolated ingredient.

Q: Several of our readers have suggested agave nectar as a low glycemic index sweetener, but it’s primarily fructose and typically contains a higher percentage of fructose than high fructose corn syrup. Both are generally made by converting something (agave nectar and corn syrup, respectively) into a syrup that has a high amount of fructose. Several articles in Hammer’s regular newsletters have blasted HFCS, so what’s the difference and why use agave nectar?
A: This answer comes courtesy of the manufacturer of Hammer Bars: “The fructose also varies as to the source and how much it is processed. Even fruits contain fructose, and fruits are quite healthy. High fructose corn syrup is highly processed and recent studies are indicating it to be the leading cause of obesity since it turns off the receptors that tell your body its full and to stop eating. Whereas Agave is merely juice of the agave plant that is reduced via heating. Agave is also low GI (Glycemic Index) so it is much better than most sweeteners. Our sweetness also comes from organic California dates that are a bonanza for your health as well as alkaline-forming.”

(Editor’s Note: Agave Syrup can also be made via an enzymatic process, similar to how HFCS is made, but we’ll assume HN uses the kind made by simply boiling down the nectar into a thicker syrup, per comments above.)

Q: Let’s talk recovery. After a workout, you want to flood the system to replace muscle glycogen and help shuttle amino acids (from protein) into the muscles, and the common assumption is that simple sugar is the quickest way to spike blood glucose levels, thus getting as much back into your muscles as possible. Hammer’s recovery product, Recoverite, contains only Maltodextrin for the carb, and has 32g carbs/3g sugar per serving. Why wouldn’t we want sugar in a recovery drink?
A: In the article “Recovery – A crucial component for athletic success (http://www.hammernutrition.com/knowledge/recovery-a-crucial-component-for-athletic-success.1278.html?sect=advanced-knowledge-section), and specifically in the section entitled “Complex carbohydrates versus simple sugars.” I write:
The one time where your body isn’t going to put up much of a fuss regarding complex carbohydrates versus simple sugars is right after a hard, glycogen-depleting workout. At this time your body is in such dire need of replenishment that it’ll accept just about anything. That said, complex carbohydrates still offer a distinct advantage over simple sugars, which is why we strongly recommend using them. Here’s why: Complex carbohydrates (such as the maltodextrin we use in Recoverite) and simple sugars (except fructose) have a high glycemic index (GI). This allows them to raise blood sugar levels and spike insulin rapidly, both desirable functions post-exercise. However, complex carbohydrates allow for a greater volume of calories to be absorbed compared to simple sugars. In other words, when you consume complex carbohydrates instead of simple sugars after exercise, your body is able to absorb more calories for conversion to glycogen without the increased potential for stomach distress that commonly occurs with simple sugar fuels.

Additionally, most of us already over-consume simple sugars from our daily diets. Numerous studies clearly show that sugar consumption in America is outrageously high. A report from the Berkeley Wellness Letter stated that each American consumes about 133 pounds (60+ kg) of sugar annually & that’s over 1/3 pound sugar every day, 365 days a year! Excess sugar consumption is implicated in a number of health problems. If simple sugars don’t offer any specific post-workout benefits, then why use them?

Q: Anything else you’d like to add?
A: I would encourage everyone to read The Endurance Athlete’s Guide to Success (http://www.hammernutrition.com/guide), and in particular regards to sugar, I’d recommend the article “Proper Caloric Intake During Endurance Exercise” (you can find this separately at http://www.hammernutrition.com/knowledge/proper-caloric-intake-during-endurance-exercise.1275.html?sect=advanced-knowledge-section)


Chocolate #9 is a sports gel formulated only with organic Agave Syrup and Belgian-style dark chocolate.  It’s a certified Low Glycemic Index product that was originally developed purely for diabetic athletes (they’re a sponsor of Team Type 1, who used the product to win last year’s RAAM and set a course record in the process).

Here’s the nutritional breakdown:


I talked to John Sample, founder of Chocolate #9, about the product.

Technically, it has sugar, as evidenced by the Nutrition Facts panel above, but it’s very low glycemic index (46, versus 105 for Maltodextrin).  While they haven’t conducted their own gastric emptying tests, this product may be applicable for diabetics and others looking for a lighter glycemic response.  Compared to glucose, agave has a much lower glycemic response (from 26 to 45), and according to C9’s tests, it doesn’t spike blood sugar levels as much, and they end up the same as before consumption, as opposed to an overall drop with glucose:


Regarding the percent solution and gastric emptying, adding any gel, regardless of carb source, to sports drink consumption is going to increase the % solids-to-solution and slow gastric emptying, so total carbohydrate grams should be figured out compared to a similarly formulated sports drink, then consume enough water to create the right % solution.  But we’re getting a bit off topic.


Pretend for a moment there were no ill-health effects to sugar consumption.  The fact that you can basically double the caloric energy intake by switching to maltodextrin over simple sugars should be reason enough…especially during rides and races lasting more than 90 minutes where you start dipping into your reserves.  It could quite easily and apparently be the difference between winning and losing…or finishing the ride strong and making your punk friends look bad.

From my experience over the past six weeks, I’ve been able to perform considerably better than expected on long (2+ hours) group rides and mountain bike rides .  And I didn’t feel (totally) drained afterward, nor did I experience any stomach cramping or GI issues during or after the rides.  It’s worth mentioning again that I’ve never really had GI issues with other sports drinks, but the improvement in my endurance performance with Hammer’s products has been noticeable.

So, assuming you’re sold on the concept, what other products are available that don’t use simple sugars?


Carb-Boom has been making gels for ten years or so, starting out with one flavor that was essentially apple sauce and maltodextrin (it even came in little apple sauce cups with the tin-foil lids!).

Now, their flavor profile has expanded quite a bit, and about half of the flavors contain no added simple sugars.  They use real fruit juice and purees to flavor and sweeten them.  The flavors with no added simple (refined) sugars are: Apple Cinnamon, Banana Peach, Raspberry, Strawberry Kiwi, Vanilla Orange and Chocolate Cherry (though these last two flavors use White Grape Juice concentrate, which is essentially glucose).

Carb-Boom’s drink mixes and gel-chews do use added sugar, however some are pretty low.  Their Endless Energy endurance drink contains 3g of sugar (partially from sucrose, the rest presumably from maltodextrin) out of 54g total carbs.

Bodybuilding products, by and large, have little if any sugar ’cause they like to be ‘ripped to shreds’ at all times.  There are a lot of recovery and “gainer” products that can be great meal replacements or recovery aids during hard training.  I’ve tried a number of them from Labrada, EAS and others that use a blend of oats, fiber, maltodextrin and healthy fats with whey protein.  Look for the ones that are made with “real food” ingredients as much as possible.  For Ready-to-Drink options, Cytosport’s Muscle Milk Light is pretty tasty but has a sometimes odd texture (tapioca?), and EAS’ Myoplex lite isn’t bad, either.  Pacific Health Labs (makers of Endurox, etc.) recently introduced their Forze line of weight management products for athletes, including a RTD shake, but I’d have to try it again before recommending it…one sample at Interbike didn’t impress me. None of these contain added simple or refined sugars.

Cytosport sells tubs of maltodextrin (CytoCarb II) if you want to mix up your own concoction. Try Kool-Aid packets for flavor, a little salt and some Stevia and/or Splenda for sweetening.  This won’t necessarily be any cheaper than buying stuff, but it’s always fun to experiment.  Actually, it can be quite a bit more expensive if you factor in failures…but oh the memories!


There are also a number of electrolyte and hydration options that provide those nutrients without any (or negligible…< 1g) calories or carbs.

The tablets (Zym, Nuun’s U and Camelbak Elixir, above) and concentrate (The Right Stuff, left) are all pretty good, and probably all you’d need for shorter rides anyway.  They all contain a lot of sodium since Sodium Bicarbonate is the base in the tablets that makes them fizz and dissolve, so take that into consideration.  Of the tablets, FWIW, Zym’s lemon lime is my favorite, and it seems to dissolve quickest, especially in cold water, but they’re all pretty good and have their own unique attributes, so I’d say try them all.

The Right Stuff used NASA science to create an isotonic solution that’s very high in sodium and says it hydrates better than anything with any carbs in it.  My first ride with it was on a trainer and I swear my quads were more pumped than ever.  Unscientifically, this suggests to me that there was a lot of water getting to the muscle, but that’s totally anecdotal.

While these last products may seem irrelevant because they have no carbs at all, if you’re looking just to improve hydration, there are a number of studies that show non-caloric electrolyte enhanced beverages do increase gastric emptying speed and improve hydration.  So eschewing products like Propel that contain 5g sugar per bottle not only reduces superfluous calories but may actually aid hydration.

For sports foods, Larabar makes some very tasty bars.  Some of the flavors (most, actually) have 20g+ sugar, but they’re made with whole food ingredients like fruits, dates and nuts…no added or refined sugars.

These, along with the Hammer Bars, are good between meal snacks or for keeping that empty stomach from driving you bonkers on your longer rides and adventures.


Hammer says any amount of added simple sugars will throw off the osmality, reduce the total amount of calories that can be absorbed and slow gastric emptying.  Since Bikerumor doesn’t have anywhere near the funds to conduct our own lab-controlled studies, I’m presenting as much information here as I could find so you can make your own decisions.  I can’t say for certain what, if any, amount of sugar in a sports nutrition product would be OK in terms of maximizing performance, but for me, none seems to be working just fine.

As for overall diet, Sweetie and I have made lots of small changes (removing sugar from our waffle mix, making more stuff from scratch, etc.).  Do we feel different?  I seem to have slightly more energy throughout the day, but nothing earth shattering.  I still crave a Coke with Mexican food, but within 20 minutes of eating, I’m over it, and glad I didn’t get it.

Sweetie says: “I feel good.  I don’t feel like snacking as much, and I don’t crave a bowl of cereal before bed anymore.”

The biggest health differences will show slowly over time, primarily in the form of better overall health, improved quality of life and a younger body than the calendar may suggest. From everything I’ve read, the science is pretty clear that sugar consumption is bad for so many parts and processes inside your body that just the knowledge of this is reason enough for us to make a permanent lifestyle change. Check back with me in 20 years.


If you’re looking to emulate this way of eating, it’s easier than it may seem at first.  The old saying about shopping the perimeter of the grocery store carries over well for eliminating added sugar, too, and has plenty of other health benefits.  Baby steps, like taking one meal at a time, can help transition your diet to one without added sugar.  To be honest, though, you’ll likely get the biggest bang for your buck by dropping things like soda, energy drinks and prepackaged snacks and desserts cold turkey.

Another easy way is to simply shop for as many of your groceries as you can at your local farmers market.  Not only do you generally reduce the amount of packaging waste, but if you avoid Joline’s Peanut Brittle stand and the like, you’ll pretty much avoid any added sugar, too.  Plus you’re supporting your local economy, reducing food miles, supporting sustainable farming…oops, getting philosophical here. You get the point.

As for sports nutrition and performance, try some of the brands above.  You’ll have to try them exclusive of your current stock of products with added sugar to really see if you benefit, but they’re no more or less expensive than any other products.  Fair warning, if you’re used to the tart, sweet flavor of most drinks, Hammer’s sports and recovery drinks’ flavors may seem a bit timid.  But you’ll probably come to enjoy the lack of a coating on your tongue, too, and it’s actually quite refreshing and (for me) helps encourage more consumption, which keeps hydration up.


Here are links to parts 1, 2 and 3 of my No Added Sugar experiment:

  • Part 1: No Sugar Added for One Month – getting started
  • Part 2: Grocery shopping surprises and disappointments
  • Part 3: The health reasons for eliminating sugar from your diet

If you haven’t read these earlier parts yet, they’ll help put the conclusion and some of these other comments into perspective.

And here are several really interesting, entertaining and highly enlightening books and movies worth checking out.  Not all are strictly about sugar, but they’re all absolutely worth carving time out for. Free at your local library, in queue at Netflix or generally cheaper on Amazon:

Hammer Nutrition also sent along the video and book by Dr. Nancy Appleton, and I’d be remiss if I didn’t mention them.  The book, Suicide by Sugar, is not as entertaining as those mentioned above, but it has the highest concentration of info, facts and cited research specifically pertaining to sugar.  Worth reading.  The video, Sweet Suicide, however, is an hour of your life you’re never gonna get back.  Sorry guys, but it’s lame, and here’s why:  Production quality blows, doomsday music and sound effects are incredibly cheesy and the information is presented poorly and anecdotally.  The authors of Freakonomics would rip it apart.  Plus, the footage is painfully old and lo-def.  It’s like a bad video they made us watch in grade school. I can’t in good conscience recommend it.  The book covers it better and actually substantiates the claims.


Got some good books, movies or products to recommend?  Leave a comment, but please keep it unbiased and on topic.  If it’s your own product, say so, but keep it informational.  Grossly blatant advertising won’t be approved, but we’re happy to include you if your product fits within the theme of this experiment.


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14 years ago

Try the new PediaLyte with zinc for your electrolytes. It doesn’t have any sugar in it, and it’s easy on the stomach. Oh yeah, it works!


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