Hydration for Runners: Why It Matters & How to Stay On Top of It

Staying hydrated isn’t just about avoiding thirst—it’s essential for your health, recovery, and performance. Water regulates body temperature, cushions joints, supports cellular energy, and helps remove waste. For runners, proper hydration can mean the difference between feeling strong and falling short.

Why Hydration Is Crucial for Runners

When we run, we produce 20 times more heat than at rest. Our bodies cool down by sweating—but sweating also leads to the loss of fluids and electrolytes (like sodium and potassium).

Losing just 2–3% of your body weight in fluid (roughly 3–5 lbs for a 150 lb runner) can lead to dehydration, causing:

• Fatigue

• Headaches

• Muscle cramps

• Increased heart rate

• Decreased performance

3 Key Hydration Tips for Runners

1. Know Your Sweat Rate

We all sweat differently—affected by temperature, intensity, fitness level, and more.
To measure your sweat rate:

• Weigh yourself before and after a run longer than 1 hour.

• For every pound lost, drink 20–24 oz of water to rehydrate.

• Pair fluids with carbohydrate- and electrolyte-rich foods (like a PB&J sandwich) to replenish energy and sodium/potassium stores.

Well-trained runners often sweat more efficiently than newer runners—it’s a sign of improved thermoregulation!

2. Hydrate Consistently Throughout the Day

• Don’t wait until you’re thirsty—that’s a late sign of dehydration.

• Sip water regularly rather than chugging all at once.

• Eat water-rich foods like fruit for natural hydration and electrolytes.

• Check your urine color: Aim for clear to light yellow.

• If consuming alcohol, rehydrate beforehand, as alcohol is dehydrating and interferes with carb storage in your muscles.

3. Drink Before, During & After Your Runs

Before your run:

• 2 hours before → Drink 16 oz of water (pair with a snack or light meal).

• 15 minutes before → Drink 6–8 oz of water.

During your run (if longer than 1 hour):

• Drink at regular intervals. Depending on sweat rate, some may need up to 16 oz every 15 minutes.

• Include carbohydrates and electrolytes—sports gels, dried fruit, or electrolyte drink tabs are great options.

After your run:

• Drink at least 16 oz of water with food.

• If you know your sweat rate, replenish 20–24 oz per pound lost.

Bottom Line

Hydration is a cornerstone of strong running. By staying on top of your fluids—and pairing hydration with the right fuel—you’ll set yourself up for success during training and on race day.

Every runner is different, so consider working with a registered dietitian to better understand your specific hydration and nutrition needs.