Sometimes skipping water and sticking to sports drink is a reasonable fueling strategy.

Q: I often skip plain water at aid stations—is that bad?

A: Not necessarily. Sometimes skipping water and sticking to sports drink is a reasonable fueling strategy, even if you’re taking in other fuel like gels and bars. But it’s important to understand why and how to do it properly.

First, let’s define “sports drink.” An ideal sports drink is a blend of around 40–50 grams of carbohydrate and 500–600 milligrams of sodium per bottle. Gatorade Endurance Formula, Base Hydro and Infinit are
good examples.

On race day, our bodies have a few simple fueling requirements: fluid, electrolyte, simple sugars and—especially in the case of long-course racing—a small amount of protein. Plain water only meets one of those requirements: fluid. Sports drink, on the other hand, meets three of those requirements: fluid, electrolytes and simple sugars. And some sports drinks on the market make it four with added protein. This alone makes sports drink a good choice, if it’s your primary fuel source.

Getting a steady stream of sports drink means that you will be taking in a steady stream of carbohydrate, and this keeps your blood sugars stable. By sipping sports drink every 5–10 minutes or so on the bike and run, you are providing carbohydrate at a constant and reasonable rate at which it can be absorbed and used. This will keep you off the blood-sugar roller coaster. Water, on the other hand, does not supply that steady sugar intake, and that can put you right on that roller coaster if you’re not careful, taking you for a ride you don’t want to go on.

If you’re going to use primarily sports drink in racing, however, you must adapt the gut to accept this strategy. A common complaint I get when I prescribe sports drink only in fueling plans is “but all that sugar makes my stomach hurt!” The solution to this potential problem is to train the gut, just like you train your legs, heart and lungs. If you take gut adaptation as seriously as you take your time in the pool, on the bike and running, your gut will be just as prepared for race day as your cardiovascular and muscular systems. This means if you require 36 ounces of sports drink per hour in racing (as determined by a sweat test), you should consistently use 36 ounces per hour on all training rides. Practice makes for a happy gut on the race course. Bear in mind everyone is different, but when approached properly, sports drinks can be an adequate fueling strategy.

Beth Shutt works with endurance athletes as a dietitian for The Core Diet. She also competes as a professional triathlete for QT2 Systems at the 70.3 and Ironman distances and serves as the operations director for training plan site The Run Formula.