First-time finishers and seasoned triathletes recognize that fuel and hydration are as important as swim, bike, and run when training for and competing in an Ironman® event. When it comes to fluids, the demands of Ironman necessitate that you choose a beverage that satisfies multiple requirements — to fuel, replenish, hydrate, deliver electrolytes, and taste great. Athletes look for fluids that will work for them, so the composition is crucial. Ironman Perform™ sports drink was designed by the sports nutrition experts at PowerBar®. It is the official sports drink found at Ironman events. What are the components of a beverage worthy of Ironman? More specifically, what is the anatomy of Ironman Perform™?

The Anatomy of Ironman Perform™ sports drink
Ironman Perform™ sports drink is designed to enhance the performance of long-endurance athletes by providing what an Ironman event demands: fluids, fuel, and electrolytes. Here’s how Ironman Perform™ sports drink works for you:

Energy: Needless to say, during an event such as Ironman, you burn a significant number of calories. The actual number of calories expended will vary based on fitness level as well as on the intensity and duration of the exercise. Given that an Ironman typically lasts 8–16 hours, sports nutrition expert and researcher Asker Jeukendrup, ED, estimates that finishers will expend 8,000–11,000 calories in a day, or about 500–900 calories per hour.(1) Although an athlete is not expected to match their calorie intake with their expenditure (try eating 900 calories per hour for 10 hours!), it is important to provide the body with energy during this all-day challenge.(1)

Ironman Perform™ sports drink provides 70 calories per 8–fl oz, so you get 175 calories in a 20–fl oz bottle.

Carbohydrates: During an Ironman competition, you need an energy source that is readily available and quickly absorbed, as well as one that offers maximal fuel to working muscles. A fine balance of carbohydrates — glucose and fructose — helps satisfy these demands by optimizing energy delivery and muscle fueling. Recent sports nutrition research revealed that a 2:1 ratio of glucose to fructose (or maltodextrin and fructose) is the most advantageous blend.(1) The 2:1 ratio of glucose to fructose has been shown to expedite gastric emptying and increase fluid delivery compared to glucose alone.(1) Because glucose and fructose each have their own transport system in the body, this formulation offers 20–50% greater energy delivery.(1) For an Ironman, aim for 90 grams/hour of this glucose and fructose blend in order to optimize performance.(1)

Ironman Perform™ sports drink contains this critical 2:1 ratio of carbohydrates in the form of PowerBar C2MAX dual source energy blend. It provides 17 grams of carbohydrates per 8–fl oz, so you get 42 grams of carbs in a 20–fl oz bottle.

Fluid: Sweating occurs during exercise to help dissipate heat produced by working muscles.(2, 3) Unfortunately, if you don’t replenish the fluid that you lose in sweat, dehydration can occur and derail performance. Dehydration is considered the single largest contributor to fatigue when training or racing.(2) Sweat losses vary between individuals and depend on the duration and intensity of exercise, environmental conditions, and the type of clothing/equipment worn.(2, 3) Between individuals, sweat rates vary due to differences in body weight, genetic predisposition, heat acclimatization state, and metabolic efficiency — i.e., how efficient you are at a particular activity.(2, 3) It's estimated that sweat rates can range from 0.3–2.4 liters per hour, so a one-size-fits-all recommendation for fluid requirements is rarely appropriate or useful.(2, 3) To make matters more challenging, thirst cannot be trusted to prompt fluid intake, because by the time that thirst hits, you might already be dehydrated.

Dodging dehydration is imperative, but overhydration — especially with plain water — should be avoided as well. Hyponatremia, or a low concentration of sodium in the blood, can be caused by overconsuming plain water without replacing sodium.(2) It appears to be more common among novice marathoners who are not lean, run more slowly, sweat less, or overconsume water before, during, or after exercise.(2)

To avoid the pitfalls of overhydration and underhydration, adjust your fluid intake to stay in your hydration zone. Regardless of your actual sweat rate, it is advised that you avoid losing more than 2% of your pre-exercise body weight during activity.(2, 3) Do this by matching your fluid intake during exercise with your sweat rate. A typical sweat rate is about 16–24 oz per hour; for a personalized plan, estimate your sweat rate with a simple test during training.(2) Visit www.powerbar.com/src to calculate your unique sweat rate.

Electrolytes: Unlike plain water, a sports beverage helps replenish electrolytes that are lost in sweat. Similar to fluid losses, sodium is lost in varying amounts. The average concentration of sodium in sweat is about 1 gram per liter.(2) Potassium, calcium, and magnesium decline to a lesser degree than sodium.(2) In addition to protecting a proper balance, replacing electrolytes during activity can help you ward off performance-inhibiting muscle cramps. Cramping might be due to dehydration, electrolyte deficits, and muscle fatigue.(2)

Ironman Perform™ sports drink provides 190 mg of sodium and 10 mg of potassium per 8–fl oz. You'll get 475 mg of sodium and 25 mg of potassium in a 20–fl oz bottle.

Flavor: Taste is paramount. If you can’t tolerate the taste, you are less likely to consume something. Ironman Perform™ sports drink is made with natural flavors and without the use of high-fructose corn syrup.

Be Confident in Your Sports Beverage

During an Ironman, you need to trust your training and be confident in your nutrition. Choose a sports beverage designed to work for you — one that provides the fuel, fluid, electrolytes, and taste to help create the best Ironman experience possible.

Dr. Jenna A. Bell is a Registered Dietitian, Board Certified Specialist, in Sports Dietetics and is co-owner of Swim, Bike, Run, Eat! She is an Ironman finisher and is currently training for Ironman Wisconsin 2010.

References:
1. Jeukendrup AE. Sports Nutrition from Lab to Kitchen. UK: Meyer & Meyer Sport. 2010.

2. American College of Sports Medicine; American Dietetic Association; Dietitians of Canada. Joint Position Statement: Nutrition and Athletic Performance. American College of Sports Medicine, American Dietetic Association, and Dietitians of Canada. Med Sci Sports Exerc 2009; 41: 709–731.

3. American College of Sports Medicine, Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American College of Sports Medicine Position Stand. Exercise and Fluid Replacement. Med Sci Sports Exerc 2007; 39: 377–390.