Sweat, Sodium, and Running Performance: What the Science Actually Says

<p>You likely have heard both sides of the debate, as one side argues that sodium supplementation is overrated, while the other side shills sports drinks with a full gram of sodium. In this episode, we dive into the research to present you with a nuanced, science-backed discussion on the widely varying sodium needs of runners. You will learn how to determine your sweat rate and sodium needs, if sodium will prevent muscle cramps, and more.</p><p><br></p><p><strong>Thank you to our sponsors:</strong></p><p>✨ <strong>Tailwind</strong>: Complete sport nutrition made simple, including hydration mixes, high-carb sport drinks, endurance fuel, and recovery mixes. Use code TREADLIGHTLY20 at <a href="https://tailwindnutrition.com/TREADLIGHTLY">https://tailwindnutrition.com/TREADLIGHTLY</a> for 20% off your first purchase.</p><p><br></p><p><strong>In this episode, you’ll learn:</strong></p><p>✅ Sweat rate vs sweat concentration</p><p>✅ The role that sodium plays in hydration, carbohydrate absorption, and more</p><p>✅ If sodium supplementation prevents muscle cramps</p><p>✅ How to know if sweat testing is appropriate or not</p><p>✅ The signs and symptoms of too much and too little sodium</p><p>✅ If sodium pre-loading works before a race</p><p>✅ Ideal sources for sodium supplementation during runs</p><p>✅ Why too low sodium can be dangerous</p><p>Tread Lightly Running is hosted and researched by Amanda Brooks and Laura Norris, MSc. Production, show notes, and graphics by Laura Norris.</p><p><br></p><p><strong>References</strong></p><p>🔬PMID: 42190283</p><p>🔬PMID: 40089940</p><p>🔬PMID: 41561158</p><p>🔬 <a href="https://link.springer.com/article/10.1186/s44410-025-00011-9">https://link.springer.com/article/10.1186/s44410-025-00011-9</a></p><p>🔬 PMID: 36431252</p><p><br></p><p><strong>If you enjoyed this episode, you may like:</strong></p><p>🎧 <a href="https://open.spotify.com/episode/3r7PQPbU5MPs2ZjgIIOdmr?si=8h7GbiEoRp-2eiG3j6Ybnw">What Your Running Gel Label Actually Means with Kylee Van Horn</a> (8 Aug 2025)</p><p>🎧 <a href="https://open.spotify.com/episode/6fi0OQiiKWWtwzAHNC94dX?si=AS1lV_1uSNaZmD0mfK3BHQ">The Science of the Long Run</a> (17 July 2026)</p><p><br></p><p><strong>Let’s stay connected:</strong></p><p>➡️ Tread Lightly Running Podcast on Instagram: <a href="https://www.instagram.com/treadlightlyrunning/">https://www.instagram.com/treadlightlyrunning/</a></p><p>➡️ Laura Norris Running on Instagram: <a href="https://www.instagram.com/lauranorrisrunning/">https://www.instagram.com/lauranorrisrunning/</a></p><p>➡️ Subscribe for weekly evidence-based newsletters, straight to your inbox, on <a href="https://lauranorrisrunning.substack.com/">https://lauranorrisrunning.substack.com/</a></p><p>➡️ Run to the Finish on Instagram: <a href="https://www.instagram.com/runtothefinish/?hl=en">https://www.instagram.com/runtothefinish/?hl=en</a></p><p>➡️ Thousands of running gear reviews and training guides: <a href="https://runtothefinish.com/">https://runtothefinish.com/</a></p>