Supplements for Runners — Running Nutrition | 6AM Run

Every summer I get the same message from runners: "I drank tons of water on my long run and still got a headache, cramps, and felt awful." Almost every time, the water wasn't the problem. The missing electrolytes were.

I'm Hami, founder of 6AM Run. Here's the plain-English version of electrolytes for runners — how they work, how much you actually need, and how to figure out your own numbers — because "drink more water" is only half the answer.

What You Actually Lose When You Sweat

Sweat isn't just water. A typical runner loses 0.5 to 2 liters of sweat per hour, and every liter carries roughly 500–1,500 mg of sodium, plus smaller amounts of potassium, magnesium, and calcium. If you only replace the water, you dilute what's left — and that's when the headaches, nausea, cramps, and late-run fade show up.

Big clue you're a salty sweater: white, crusty streaks on your hat, face, and shirt after a run, or sweat that stings your eyes. Salty sweaters sit at the high end of those sodium numbers and need a more deliberate plan.

Sodium: The One That Matters Most

Sodium is the electrolyte you lose the most of, and it's the one that drives most of the symptoms. Practical targets most runners do well with:

• Easy runs under 60 minutes: plain water is fine. Eat normally and you're covered.
• Runs of 60–90 minutes: about 300–500 mg of sodium per hour during the run, especially in warm weather.
• Long runs and races over 90 minutes, or hot days: 500–1,000 mg per hour. Heavy, salty sweaters in the heat may need the top of that range or slightly above.
• After the run: pair fluids with salty food or an electrolyte drink — sodium is what lets your body actually hold onto the water you drink.

Potassium and Magnesium: The Supporting Cast

You lose far less potassium and magnesium in sweat than sodium, and normal meals replace them easily (bananas, potatoes, leafy greens, dairy, nuts). Aim for potassium-rich foods across the day rather than chasing supplements for it, and think of magnesium as a daily-diet item, not a mid-run fix. Sodium is where races are won and lost; the rest is supporting cast.

Signs You're Getting It Wrong

• Too little sodium/fluid: rising heart rate at the same pace, headache, muscle cramps, dizziness, dark urine, and a sudden "I'm just done" feeling.
• Too much plain water: a sloshy stomach, puffy hands, nausea, and confusion. This is the dangerous direction — overhydrating with plain water on very long, hot efforts can dilute blood sodium (hyponatremia). Drink to thirst, and include sodium on long runs.
• Cramps: usually a mix of fatigue and electrolyte loss. Sodium during the run plus better pacing fixes most "cramp-prone runner" stories I hear.

Test Yourself: The Simple Sweat-Rate Check

Want your personal numbers instead of generic ranges? Do this once on a typical training day:

• Weigh yourself naked (or in minimal clothing) right before a 60-minute run.
• Run without drinking (or track exactly how much you drink).
• Towel off and weigh yourself again right after.
• Every pound lost ≈ about 16 oz (roughly half a liter) of sweat. Add back anything you drank to get your true hourly rate.

Repeat it on a hot day and a cool day. Now you know your range, and you can plan bottles and sodium per hour like the runners who always look strong at mile 18. This is also the foundation of good race fueling — it pairs with a carb schedule like the one in my half marathon fueling plan. And if you're building toward the full 26.2, my marathon supplements guide puts the whole before, during, and after picture together.

My Simple Routine (What I Use and Why)

I keep it boring, because boring works. Before morning runs, my pre-run drink is MARATHON — it's the ritual that gets me out the door, and I always check that what I drink around training lists real sodium amounts rather than a sprinkle for the label. On long runs I'll carry an electrolyte drink — usually HYDRABLAST — or salt tabs in heat, and after hard sessions I eat a real, salty meal within the hour — often with FINISHLINE in the mix for recovery. The specifics matter less than the habit: sodium before, during, and after anything long or hot.

Do Sports Drinks Actually Cover It?

Sometimes — read the label before you assume. Many big-name sports drinks contain only about 100–200 mg of sodium per bottle, which is a fine start for an hour run but well short of the 500–1,000 mg per hour a salty sweater needs on a hot long run. Check the sodium line specifically (not just "electrolytes" on the front of the bottle), and stack sources if you need to: drink plus a gel with sodium, or drink plus salt tabs. Your stomach will also tolerate electrolytes better when they come in gradually with fluids rather than in one big hit.

Quick Reference: Electrolytes by Run Type

• 5K / easy 30–45 min: water to thirst; no mid-run electrolytes needed.
• 60–90 min: water + 300–500 mg sodium/hour.
• 90+ min / race day / heat: 500–1,000 mg sodium/hour, fluids to thirst, sodium with your recovery meal.
• Salty sweater or temps above 80°F: start at the high end of every range above.

Dial in your sweat rate once, match your sodium to the length and heat of the run, and those "I drank plenty but still crashed" days mostly disappear. Electrolytes are one piece of the puzzle — my complete guide to supplements for runners covers the rest. Run early, fuel smart. — Hami