When the Heat Is on: The Science of Rehydration from Elite Athletes to Everyday Exercisers

Rehydration Requires More Than Just Water

Many people focus on drinking enough water, but proper hydration also depends on maintaining the right balance of fluids and electrolytes. Key electrolytes such as sodium, potassium, and magnesium play an essential role in maintaining your fluid balance and supporting muscle function and nerve signaling.

Some common rehydration mistakes athletes make:

• Waiting until they feel thirsty
• Replacing only water
• Ignoring sodium/electrolyte losses

The best electrolyte drinks are those that replenish the nutrients lost through sweat.  In some situations, during intense exercise, replacing fluids lost only with water can dilute electrolyte levels and leave the body inadequately hydrated. Additionally, plain water does not provide glucose, which helps the body absorb fluids more effectively when paired with sodium.

Elite Recovery: Lessons From the Pros

Sometimes the toughest challenge in competition isn’t the opponent, it’s the heat. While athletes can’t control the weather, they can control how they prepare and perform in it. Experienced athletes understand that hydration strategies should adapt to the environment, especially in hot and humid conditions.

A  simple hydration plan can help athletes stay prepared and perform their best in the heat:

• Before exercise: Start hydrating early. Drink 17-20 fl oz of a sports drink or water about 2-3 hours before exercise.
• During exercise: Aim to drink 7-10 fl oz every 10-20 minutes, during intense exercise or especially in hot, humid weather.
• After exercise: Continue rehydrating over the next several hours to replace fluids and electrolytes lost through sweat.

Elite athletes know that preparation and recovery for practice and competition is a critical competitive edge and are key components of performance.

Hydration Strategy Matters at Every Level

Hydration challenges aren't limited to elite athletes. From long training runs and summer camps to recreational leagues and high school or college sports, athletes at every level can be affected by dehydration and heat stress. No matter the level of competition, athlete safety should always come first. You don’t have to compete on a world stage to experience the risks associated with dehydration and exercising in the heat.

Key hydration reminders include:

• Quench Your Thirst with Water to replace fluids lost: By the time you feel thirsty, dehydration may have already begun.
• Electrolytes: Replace both fluids and electrolytes to help the body retain and balance fluids.
• Be mindful of environment: Adjust hydration strategy based on temperature, humidity and sweat loss.

For runners preparing for fall events such as the Abbott World Marathon Majors, staying ahead of fluid and electrolyte losses is an important part of consistent preparation and recovery throughout demanding summer training cycles.

What This Means Beyond Competition

Effective hydration is about more than simply drinking water. It also depends on the beverage composition in addition to fluid intake. Athletes hydration needs can vary based on several factors, including duration of exercise, workout intensity, duration and frequency, and opportunities for rehydration (breaks in practice, fluid bottles on bikes) during activity.

Key components that support rehydration include:

• Water: replaces fluids lost through sweat
• Sodium: supports fluid retention and distribution; most critical electrolyte
• Potassium: supports muscle and nerve function
• Glucose/sugar: supports fluid absorption when paired with sodium

Built for Rehydration: What Makes Pedialyte Different

Not all hydration electrolyte drinks are designed the same. Some sports drinks are built primarily for energy during endurance activity, while oral rehydration solutions like Pedialyte^® are formulated to help replenish fluids and electrolytes lost through sweat. With 2x electrolytes and 50% less sugar vs the leading sports drink, Pedialyte helps you rehydrate and feel better fast. For athletes training in hot conditions, finding the best electrolyte drink that includes the right balance of sodium, fluids, and glucose can make a meaningful difference in rehydration.