Formulas for Fueling and Hydrating on Race Day

by | Updated: December 3rd, 2016 | Read time: 2 minutes

Q: I have a hot 70.3 on my schedule. What do I need to know about hydration and fueling leading up to and on race day?

Brandon Marsh answers:

A: This is a common concern and a question we get often. First, it’s important to understand hydration and fueling needs are very dependent on the individual. However, there are a few universal “formulas” that can help you endure race day.

Race Day Hydration:

Formula = 30 ounces of fluid/hour

The average athlete will need about 30 ounces of fluid per hour of activity. You may need slightly less or more, depending on your body weight, pace and the conditions of the course.

Hydration schedule = sip on a sports drink or water every 10 to 20 minutes

Some experts have advised drinking whenever you feel thirsty. However, that may be too late. Instead, I suggest sticking to a schedule. For instance, I generally take in 40 ounces per hour, sipping on something every 10 to 15 minutes.

Race Day Fueling:

Formula = 80 grams of carbohydrates/hour

When we talk about fuel we’re talking about calories. A sweet spot for endurance fueling is about 80 grams of carbohydrates per hour of activity, which equates to 320 calories. Again, your individual needs may vary; some athletes operate well on just 60 grams of carbs per hour, or 240 calories. Find your own sweet spot during long training sessions and be sure to experiment with different sources of carbs.

Fuel sources = sports drinks, gels, bars, bananas

Think about how you’ll be toting your fuel through the race. Gel packets may be most convenient, but sports drinks may be the easiest to digest. Explore your options. It’s also wise to schedule your calorie intake for certain mile markers, taking in consideration the water and fuel stations along the course.

Pre-Race Preparation:

It’s easy to overeat before a race when you’re trying to fuel yourself for a long road ahead. Since you have rested a bit in tapering, you don’t need to consume extra in preparation. Overdoing it may even result in weight gain. Keep it simple. Eat just until full and take in sufficient electrolytes. I like to add a couple NUUN tablets to my water the day before. And if it’s going to be an especially hot race, I will take salt tablets to help balance my electrolyte levels.

Most importantly, I advise you try these hydration and fueling tips before your race, during key training sessions. Long brick, anyone?

Amy Marsh is a four-time Ironman champion, two-time IronDistance champion, and was named the 2010 USAT Long Distance Triathlete of the Year. Brandon Marsh has been competing in triathlons since 1988, and can be counted on to be a top-10 contender in every event he enters. Got a question about swim-bike-run or sports nutrition for Team Marsh? Email them at “˜Like’ them on  Facebook  or follow on Twitter: Brandon @BrandonMarshTX and Amy @AmyCMarsh.