Recently I was contacted by RaceRx, a new fueling company in San Diego, about trying out their cassava-based sports drink. It's pretty unusual in its formulation, and given my fairly strict adherence to a FODMAP diet, which has me avoiding the fructose and sugar alcohols found in 99% of the sports drinks and gels out there, I was quite eager to try it.
Their RaceRx advanced endurance fuel uses a proprietary ultra-long-chain carbohydrate called HDA which is derived from cassava starch as a slow-acting glucose source, and contains no grain-derived sugars (it is sweetened with stevia). This makes it great for the fructose-sensitive like me, those avoiding corn due to a food allergy (which is what maltodextrin is derived from), and others who are sensitive to or avoiding high sugar (perhaps diabetics?). In fact I tested it out on two friends with gluten/corn and sugar issues, and both have had good results with it.
Unlike maltodextrin, which is composed of relatively short chains of 3-17 glucose molecules and breaks down pretty fast, their cassava-based amylopectin molecules contain millions of glucoses that are slowly released during digestion in the small intestine. You can learn more about amylopectin here. While the really long glucose chains are key to the great digestive and energy-producing properties of the drink, they also have the effect of limiting the solubility of the solution. It stays cloudy, and you will need to mix it up each time you take a sip to resuspend it. Overall the drink goes down easy and is not thick or chalky, and the powder suspends in water very easily.
Other things to know about RaceRx Advanced Endurance Fuel: It contains 120 mg sodium per 120 calorie, 16 ounce, serving as well as potassium, calcium, and magnesium for a well-rounded electrolyte profile. It also contains 25% of all B vitamins, which isn't totally necessary, but probably doesn't hurt since these vitamins tend to get used up during fuel metabolism on a very long or hard ride. Bromelain is also included as a digestive agent and anti-inflammatory (derived from pineapple). Citric acid and "natural flavors" give it a very welcome citric taste. While the fact that it doesn't dissolve makes it taste just a little powdery, I really like the citrus flavor.
I used this product for my training and racing for Ironman 70.3 Texas (Galveston) in spring 2015 at 120 calories/12 oz (three 4oz doses per hour, each chased with water), and noted a lot less gas and good energy while using it. It was also more convenient than mixing up the maltodextrin/Endurolyte/Crystal Light powders I had used previously, and tasted better. I believe it would work very well for Ironman and other long bike training and racing as well, and testimonials on the website indicate that ultra runners are also using it. For shorter, more intense efforts, purely from a biochemical point of view, a faster acting carbohydrate source like maltodextrin, glucose or sucrose might be a better choice. However, I plan to test ATF in my late season short-course events and see if it is effective there as well.
RaceRx is available in tubs of 1 kg (2.2 lbs, 27 servings) directly from RaceRx on their website for $39.99, and shipping appears to be free to Texas at the moment (no sales tax either). You can also use the coupon code "TrainerCasey" to get 5% off your order (you're welcome!). I highly recommend trying it if you have a history of GI or food-allergy issues with other sports products!
Side note: if you tend to be a bit more gassy than the average person, might be worth your while to look into the FODMAP diet to see if it might help you. Eliminating onions, cruciferous veggies, whole wheat and certain fruits has been a sad undertaking (they used to be the base of my diet), but I experience far less bloating and gas on a day-to-day basis now.