Lethargy, fatigue, heat exhaustion, hyperthermia, heat stroke, passing out, and losing consciousness are signs of fluid-electrolyte imbalance in athletes. Electrolytes are charged ions (hence “electro”) that can be lost through sweat. In the body, those charges are used to drive nerve communication and muscle and heart contractions. Sweat contains electrolytes like potassium, magnesium, chloride, calcium, iron, phosphorus, and zinc, but athletes lose sodium in highest amounts.

How do I replenish fluid loss?

  • Try your best to replenish fluid as closely to your sweat rate as possible. Drinking too much fluid can be just as harmful as not drinking enough. According to the CDC, sweating rate = pre-exercise body weight – post-exercise body weight + fluid intake – urine volume/exercise time in hours
  • If you don’t know your sweat rate, aim for about 1 cup every 15-20 minutes.
  • Cold fluid decreases sweat rate and is absorbed faster than warm water. Ice slushes can also help.
  • Athletes can’t rely on thirst drive because it doesn’t kick in in time. By that point, you have already lost your ability to regulate your body temperature. Drink early and at regular intervals.
  • Aim to maintain your pre-exercise weight before and after exercise.

How do I Replenish Sodium Loss?

  • Athletes need to replenish sodium if they’re going to be working out longer than 1-2 hours.
  • You can eat salty foods prior to activity to try to get ahead of it.
  • Aim for 500-700 mg/L of sodium in recovery drinks.
  • Carbs enhance sodium and water absorption.

A great practice or athletic event starts at home with proper fueling and hydration throughout the day. Eat a nutrient dense diet that contains enough water and electrolytes so that you avoid deficiencies and start your workout with optimal levels. Replete after exercise so that you begin your next workout in tip top shape.

Our dietitians and health educators build customized nutrition plans that consider your unique energy, micronutrient, and fluid needs. We also teach you how to optimize your food and beverage timing for peak performance. Schedule your free in-person or remote assessment!

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