How to Stay Hydrated During Long Runs: Essential Tips for Runners

Long runs are a cornerstone of marathon training, but they also present unique hydration challenges. As you log mile after mile, your body loses water and essential minerals through sweat, which can lead to fatigue, cramping, and decreased performance. Proper hydration isn't just about drinking water—it's about replacing the electrolytes your body needs to function at its best.

In this guide, we'll walk you through the science of hydration for endurance athletes, share practical strategies for before, during, and after your runs, and highlight key products that can help you stay salty and hydrated. Whether you're training for your first half-marathon or your tenth full marathon, these tips will keep you going strong.

Why Hydration Matters for Long Runs

When you run for more than an hour, your body loses significant amounts of water and electrolytes like sodium, potassium, and magnesium. Even mild dehydration—losing just 2% of your body weight in fluid—can impair your performance, increase perceived effort, and raise your heart rate. More severe dehydration can lead to heat illness, muscle cramps, and dizziness.

Electrolytes are critical because they help regulate nerve function, muscle contractions, and fluid balance. Sodium, in particular, is the primary electrolyte lost in sweat. Without enough sodium, you may experience hyponatremia (low blood sodium), which can be dangerous. That's why many runners turn to electrolyte supplements like LMNT Zero-Sugar Electrolytes to maintain proper levels without the added sugar found in traditional sports drinks.

• Aim to start your run well-hydrated: drink 16-20 ounces of water 2-3 hours before.
• For runs over 60 minutes, consume 30-60 grams of carbohydrates and 500-700 mg of sodium per hour.

Pre-Run Hydration Strategy

Hydration doesn't begin when you start running—it starts the day before. To ensure you're properly hydrated for a long run, focus on consistent fluid intake throughout the day. A simple way to check is to monitor your urine color: pale yellow indicates good hydration, while dark yellow means you need more fluids.

In the hours before your run, drink water and consider a small electrolyte boost. Many runners find that taking an electrolyte packet with breakfast helps them start on the right foot. Products like the LMNT Variety Pack offer a range of flavors, making it easy to find one you enjoy. Just mix a packet with water about 30 minutes before heading out.

• Avoid excessive caffeine or alcohol the night before, as they can dehydrate you.
• Eat a light, easily digestible meal 2-3 hours before your run.

Hydration During Your Long Run

During the run, your goal is to replace fluids and electrolytes at a rate that matches your sweat loss. This varies by individual, but a good rule of thumb is to drink 4-6 ounces of fluid every 20 minutes. For runs longer than 90 minutes, you'll need to consume both water and electrolytes.

Carrying fluids can be a hassle, but using a handheld bottle or hydration vest makes it manageable. For a convenient option, consider the Stay Salty Water Bottle, which is designed to keep your drink cool and accessible. Alternatively, the LMNT Sparkling 16oz provides a refreshing, carbonated electrolyte drink that can be a nice change of pace during a hot run.

• If you don't like carrying a bottle, plan your route around water fountains or stash bottles ahead of time.
• Listen to your body: if you feel thirsty, you're already slightly dehydrated.

Post-Run Recovery Hydration

After you cross the finish line, your body needs to replenish fluids and electrolytes to kickstart recovery. Weigh yourself before and after your run to estimate fluid loss—for every pound lost, drink 16-24 ounces of fluid. But don't just drink water; include electrolytes to help your body absorb the fluid and restore balance.

A quick post-run habit is to mix an electrolyte drink within 30 minutes of finishing. The LMNT Zero-Sugar Electrolytes are a great choice because they deliver a precise ratio of sodium, potassium, and magnesium without any sugar. Pair it with a carbohydrate-rich snack for optimal glycogen replenishment.

• Avoid overhydrating with plain water, which can dilute your sodium levels.
• Include a salty snack or meal to help retain fluids.

Common Hydration Mistakes to Avoid

Even experienced runners make hydration errors. One common mistake is relying solely on water during long runs, which can lead to electrolyte imbalances. Another is drinking too much water too quickly, causing stomach discomfort or hyponatremia. Finally, ignoring individual sweat rates can leave you under- or over-hydrated.

To avoid these pitfalls, practice your hydration plan during training runs. Experiment with different electrolyte products and timing to find what works best for you. The LMNT Variety Pack is perfect for testing flavors and finding your favorite, while the Stay Salty Hat can help keep you cool and focused under the sun.

• Don't wait until race day to try a new hydration strategy—test it during training.
• If you sweat heavily, consider adding extra sodium to your pre-run meal.

Mastering hydration for long runs takes practice, but the payoff is huge: better performance, faster recovery, and more enjoyable miles. Start by fine-tuning your pre-run routine, experiment with electrolyte products during training, and always prioritize post-run replenishment. For a reliable, sugar-free option that delivers the electrolytes you need, check out the LMNT Zero-Sugar Electrolytes and find your perfect hydration partner.