The Forgotten Half of High-Carbohydrate Racing: Hydration

When we talk about the nutrition strategies of elite triathletes, cyclists and ultrarunners, the conversation almost always comes back to one number:

How many grams of carbohydrate per hour?

80 grams.
90 grams.
120 grams.
And now, increasingly, 160 grams or more.

But there is another number that may be just as important—and it is often overlooked:

How much are you drinking to actually tolerate all those carbohydrates?

This is one of the things that has caught my attention watching the Norwegian approach to long-course racing.

Kristian Blummenfelt has talked openly about targeting around 160 g of carbohydrate per hour during his training and race preparation. And in a recent video from Kona, Kristian himself said that his plan for the race is to take approximately 2 liters of fluid per hour. He also said he used this approach during his recent Super Sunday training session.

That is a huge amount of fluid.

And I think this is an important part of the conversation that can easily get lost when everyone focuses on the headline number of 160 g of carbohydrate per hour.

Carbohydrate doesn’t exist in isolation

When you dramatically increase carbohydrate intake during exercise, particularly when using concentrated carbohydrate drinks, gels and other products, the amount of fluid you are consuming becomes part of the equation.

You cannot simply keep adding carbohydrates and assume the stomach will continue to cooperate.

Hydration, carbohydrate concentration, gastric emptying and gastrointestinal tolerance are all connected.

This is particularly relevant in a race like Kona, where heat and humidity can dramatically increase sweat losses.

So when we see an elite athlete consuming enormous amounts of carbohydrate, we shouldn’t look only at the number of grams of carbohydrate.

We should also ask:

How much fluid is going with it?

160 g/hour isn’t magic

This is where I think athletes can get the wrong message from the Norwegian approach.

There is currently no reason to believe that 160 g of carbohydrate per hour is universally better than 80 or 90 g/h.

What we are seeing, however, is an evolution in endurance sports.

More and more elite triathletes, cyclists and ultrarunners are experimenting with 120, 140, 160 g/h and even higher carbohydrate intakes.

But the important word is tolerate.

The goal isn’t to consume the biggest number possible.

The goal is to consume as much carbohydrate as you can effectively absorb and utilize without creating gastrointestinal problems that compromise your performance.

You have to train the gut

You wouldn’t decide to ride 180 km at race intensity without training your legs.

So why would you decide to consume 160 g of carbohydrate per hour for the first time on race day?

High carbohydrate intake needs to be practiced.

And so does high fluid intake.

That means your key sessions are the laboratory.

Try your race bottles.

Try your gels.

Try the concentration.

Try the amount of water.

Try it at race intensity.

And, importantly, try it when you’re tired and when you’re training in conditions similar to race day.

You want to know what your stomach can handle before you arrive in Kona.

The 2-liter number is individual

This is where I want to be very clear.

Kristian saying he plans to drink 2 liters per hour in Kona—and using that strategy during his Super Sunday session—doesn’t mean that every athlete should drink 2 liters per hour.

His strategy is based on his own physiology, sweat rate, training, race conditions and ability to tolerate that amount of fluid.

For another athlete, 2 L/h could be unnecessary or even excessive.

The lesson isn’t:

“Drink 2 liters per hour.”

The lesson is:

“If you’re going to push carbohydrate intake to extreme levels, you also need to understand the hydration requirements of your individual strategy.”

That’s a very different message.

The Norwegian lesson isn’t “drink 2 liters and eat 160 grams”

The real lesson is much more interesting.

Elite athletes are pushing the limits of what the gastrointestinal system can tolerate because their energy expenditure is enormous.

But those numbers are the result of years of training, testing and individualization.

If you want to experiment with higher carbohydrate intake, don’t jump from 70 g/h to 160 g/h overnight.

Build it.

Test it.

Add fluid.

Monitor how you feel.

Pay attention to your body weight before and after training, sweat rate, gastrointestinal symptoms and performance.

And test the strategy in the same type of conditions in which you intend to race.

Because ultimately, the best nutrition plan isn’t the one with the highest carbohydrate number.

It’s the one that allows you to keep fueling, keep drinking and keep producing power and pace when the race gets hard.

That’s perhaps the biggest lesson from watching the evolution of nutrition among the best endurance athletes in the world.

**Carbs get the headlines.

But hydration may be what makes the carbs possible.**