All liquid race nutrition is an ever-growing trend in ultra-endurance sport. Companies are offering higher calorie drink mixes with different types of carbohydrate to aid in digestion and absorption and provide all the calories you need solely from fluid. Brands include Hammer Perpetuem and E-load + extra E-load Fly (a maltodextrin) product, and Carbo Pro etc. These products use maltodextrins (a form of carbohydrate) to be able to increase the carb (and thus calorie) content of their drinks, without leading to greater osmolality which can head to poor absorption.

The body can only absorb between 250-350 calories per hour even though you’re burning upwards of 600 calories per hour. The goal of during-race nutrition is not to replace all the calories being burned, but rather to maintain blood glucose levels and provide a source of carbohydrate to working muscle after stores are depleted. Thus, getting all your nutrition from a drink is very possible and is an option for athletes who want a no fuss approach or have had GI issues with consuming solid foods.

Typically, when you are exercising with greater intensity, your body cannot handle solid food that well because blood flow is directed to your muscles instead of your gut. That is why simple and easy-to-digest foods (gels, drinks, sport “candy”) are helpful. In addition, some foods are difficult to chew and consume while doing an activity where you need to focus on staying upright.

I would consider the all liquid approach for athletes who are trying to achieve a time goal at the 70.3 or IM distance or if someone has had difficult eating solids in the past. For example, an athlete looking to beat the 11 or 12 hour time goal in an IM race. It’s not the only way to go of course as most athletes can train themselves to be able to consume foods, even during race conditions with practice.

Keep in mind that “flavour burn-out” is common and you may want to have some back-up products and solid foods just in case you can’t stomach another bottle of your chosen drink.

As always, one product does not suit all and it’s important to try out different options in training sessions and race simulations.

Alexis Williams is a Registered Dietitian and Personal Trainer in Burlington Ontario. She is an avid triathlete and will race Ironman Louisville later this year. Visit her website www.transitionhealth.ca for more information or to contact Alexis for nutrition coaching services.