Race Fueling

A Triathlete’s Guide To Salt

As the temperatures rise, long-course triathletes can benefit from adding extra electrolytes to their race-day nutrition plans.

As the temperatures rise, long-course triathletes can benefit from adding extra electrolytes to their race-day nutrition plans.

Even those who proclaim not to sweat much will feel the effects of sweating out water and key electrolytes during long, hot training sessions. If you’re confused about exactly how much sodium you need and when, you are not alone—I get the same questions on salt and electrolyte supplementation from triathletes every year.

The bottom line seems pretty simple at first glance: Endurance athletes need to replace the fluids, carbs and sodium lost during endurance training and racing. Sports drinks contain both flavor (from sugar/carbs) and sodium (from various forms of salts) to help increase the drive to drink and ensure optimal hydration.

Many triathletes will choose to alternate between sports drink and plain water (to take a gel or with solid foods on the bike, or to add additional fluid intake in the heat) and will therefore need to rely on supplemental salt.

Why use extra salt?

It is possible to be both dehydrated (low in total body water) and hyponatremic (dilution of electrolyte sodium in blood, leading to swelling of cells). This is because for hours on end you sweat out not only water but also key electrolytes, including sodium. Countering that fluid loss by drinking plain water means you’ll not only not retain the fluid as needed (because it doesn’t contain the sodium needed for fluid retention) but you’ll also further dilute the electrolytes left in the bloodstream.

The options at right provide electrolytes, not fuel, so consume them in addition to your carb-rich sports drink. Learn your sweat rate, choose a drink you like, and the rate you can realistically consume that drink during your race. Then add supplemental carbs and sodium appropriately, and practice!

RELATED: A Half-Ironman (70.3) Nutrition Plan

Do the Math

1 liter (32 ounces)
Typical triathlete fluid/sweat loss per hour

750–1000 milligrams
Amount of sodium athletes should replace per hour

110 milligrams per 8 ounces
Amount of sodium in a typical sports drink (or 440 milligrams per 32 ounces). Gatorade Endurance, which will be served on Ironman courses again in 2015, contains 200 milligrams of sodium per 8 ounces.

RELATED: Nutrition On Long Bike Rides

How to Supplement

Here are two examples of how to incorporate electrolyte supplementation into your hot-weather racing nutrition plan.

Triathlete 1: 160 pounds, needs 32 ounces per hour of fluid intake, salty sweater per observation. Plans to consume 24 ounces of Gatorade Endurance per hour on the bike (total 600 milligrams sodium, 150 calories)
Add per hour: 8 ounces of water as needed, 1 energy gel, 1 Thermolyte tablet

Triathlete 2: 120 pounds, needs 32 ounces per hour of fluid intake, moderate salty sweater per observation. Plans to drink 16 ounces of sports drink with 200 milligrams of sodium per 8 ounces and 16 ounces of water per hour on the bike.
Add per hour: 1/4 PB&J sandwich for calories and 1 “lick” of BASE Performance salt per hour

RELATED – 2015 Triathlete Buyer’s Guide: Nutrition

Basic electrolyte tabs

Hammer Nutrition Endurolytes
80 milligrams of sodium and 50 milligrams of potassium per 2 capsules

Hammer Nutrition Endurolyte Extreme
120 milligrams sodium, 75 milligrams potassium per capsule

Thermolyte Meta-Salt
330 milligrams sodium and 85.2 milligrams potassium per serving

Effervescent tabs

Nuun Active
The brand says its tabs are absorbed more quickly, thanks to the effervescence. Many athletes like the subtle flavors (once dissolved in water).

GU Hydration Drink Tabs
A new look and new ingredient: Gu recently switched from sorbitol to xylitol, as the latter has less chance of causing dreaded GI distress.


BASE Performance Electrolyte Salt
This will be available on U.S. Ironman courses this year and comes in a small tube. You lick your thumb pad, pop the cap on the tube, put your thumb over the opening to coat your thumb with salt, then lick it off. You’ll lose a little salt in the jostling, but the saltiness is a welcome flavor balance to sugary nutrition products. Each 20-serving tube contains 290 milligrams of sodium and 2.6 milligrams of potassium.

The Right Stuff
This product is a “supercharged” electrolyte supplement developed by NASA. If you sweat a lot, take this before or during exercise, mixed with water. A 20-milliliter serving provides 1,780 milligrams of sodium, so it’s not to be taken lightly or quickly—sip it over time to prevent too much water from being drawn into the gut with such a high concentration of sodium.

Gatorade Gatorlyte Electrolyte Powder
The powder comes in a single-serving pouch (which you can mix into a sports drink) and contains 780 milligrams of sodium and 400 milligrams of potassium.

Lauren Antonucci is a board-certified specialist in sports dietetics, three-time Ironman finisher and the founding director of Nutrition Energy in New York City.