Your Post-Run Electrolyte Drink Might Be Useless (and What Actually Works)
Estimated read time: 4.1 minutes (about as long as it takes your favorite running influencer to post a “gritty” race recap explaining why sub-3 was never the real goal 🤣)
Hey Performance Nerds! Jonah here. 🤓
Most runners reach for electrolytes after every run, thinking it boosts recovery.
Your post-run meal does more. The drink is often unnecessary.
We’ve covered daily use and mid-run timing. Now Part 3 answers the recovery question everyone asks.
Here's what you'll learn today:
When sodium actually matters after training
Why food beats any recovery drink for rehydration
Simple decision framework: when to skip the supplement, when to use it
(Augie drinks plain water after our runs and still has energy to bark at every squirrel until I’m deaf. Turns out his kibble > my $4 recovery drink.)
🗽 Congrats, NYC — You Did It
To everyone who just ran the New York City Marathon, huge congratulations.
It was incredible to see so many of you out there, pushing through, finishing strong, and chasing goals you’ve worked toward all year.
I’d love to hear how it went for you. How you felt out there, if you hit a PR, or what the day meant to you.
Hit reply and tell me everything. I read every message and can’t wait to celebrate with you.
🧬 Performance Sponsors:
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SiS—the same science-backed fuel trusted by Olympic marathoners—is now sponsoring Marathon Science.
From gels to recovery tools, every product is backed by real performance data and built for serious athletes like you.
🚀 Power Your Pace with Stryd
Stryd — the running power meter trusted by serious athletes — is now an official performance sponsor of Marathon Science, delivering real-time pacing precision so you can train smarter and race faster.
💡 See this week’s full Stryd training tip at the end of this newsletter.
🧬 Your Body Already Solved the Sodium Problem
Here's what happens after every run:
Your kidneys detect the sodium deficit and immediately flip into conservation mode. They stop dumping salt in your urine.
Your thirst mechanism kicks in naturally. You drink. Your sodium concentration normalizes.
Even after major deficits, most athletes restore sodium balance within 24 hours. No supplements required.
Research shows your body is built for this. The "replace what you lost" marketing ignores how good your kidneys are at their job.
🍽️ Food vs. Fluids: Why Your Sandwich Wins
Plain water alone often gets flushed out fast.
Drink a liter of water post-run and your kidneys treat it like an intruder. You pee most out within an hour..
But add food to the equation?
That sandwich or bowl of rice includes sodium, nutrients, and calories. This combo helps your body actually retain the water you're drinking.
A typical salty meal delivers ~500–1000 mg sodium.That's more than most recovery drinks, plus carbs and protein your muscles actually need.
Research shows plain water + food beats zero-calorie electrolyte drinks every time.
🔧 The Decision Framework: When Recovery Drinks Actually Help
Most runs? Skip it. But here are the specific scenarios where sodium matters.
Scenario | Need Electrolytes? | Why? | What to Do |
Easy run ≤90 min + normal meal | ❌ No | Food + thirst restore balance | Water + salty meal or snack |
Long/hot run >2–3 hours | ⚠️ Maybe | Large losses; meal delayed | Use sodium drink if meal is >2 h away |
Two-a-days / short turnaround | ✅ Yes | Rapid rehydration needed | Sodium in fluids + carbs + protein |
Water-only for hours | ✅ Yes | Low-energy fluids flush out faster | Add ~300–600 mg Na/hr until next meal |
Pattern: Electrolytes help when you’re chugging plain water and can’t eat soon. Otherwise, just eat.
🚨 The Myths We Need to Kill
Myth: "I'll cramp tomorrow if I don't replace salt now."
No evidence supports this. Cramping is often fatigue and neuromuscular issues, not salt.
Myth: "I need an electrolyte drink to recover properly."
Only if you're not eating for hours. Your dinner already contains more sodium than that drink.
Myth: "More salt helps me hold more water."
Only true when drinking plain, low-calorie fluids in isolation. With food, you don't need the extra sodium supplement.
🎯 Practical Summary: Food Beats Formulas
Key takeaways:
Under 2 hours: Your normal food and fluids restore balance. Skip the recovery drink.
Hot or long runs: Add sodium only if your next meal is 2+ hours away.
Multiple-session days: Sodium drinks speed rehydration when time is tight.
The big picture: Post-run meal > recovery drink marketing.
Exceptions:
Another hard session soon? If you finished very depleted and train again the same day or next morning, add sodium to your rehydration drink.
No salty food for a while? If you won’t eat or drink anything salty for a few hours, electrolytes can bridge the gap until your next meal.
Bottom line: Your kidneys solved the sodium problem before you finished your cool-down. Your dinner finished the job. That $4 drink? Just insurance you didn’t need.
💬 One last thing before you go.
Still unsure when electrolytes actually make sense — before, during, or after your run
Hit reply and tell me where you’re getting stuck. I read every message and I’m here to help you dial in your sodium plan before race day.
— Jonah
Are You a True Running Nerd? Prove it.. 🧐
Welcome to the prove you’re a nerd section. Each week, I ask a question about a common running science myth.
Answer correctly, and you’ll be entered into a weekly raffle to win a package of Jonah’s favorite supplements.
What type of shoe drop puts the most stress on your calves?
Last Week’s Results: The Heat Is Healing 🔥🩸
Looks like the cold plunge crowd just took one on the chin. Most of you knew it, when it comes to long-term recovery and adaptation, heat probably beats cold.
The correct answer?
A. Heat boosts muscle blood flow, mitochondrial signaling, and satellite cell activity, which might accelerate repair and adaptation 🔥💪 ✅
While ice numbs soreness by constricting blood flow, that same constriction can delay the delivery of nutrients and repair signals. Heat, on the other hand, opens the floodgates — improving circulation, stimulating mitochondrial biogenesis, and activating the same muscle-building cells that strength training does. It’s not just comfort; it’s cellular remodeling.
Here’s how the votes shook out:
🟩 A. Heat boosts blood flow, mitochondrial signaling, and repair 🔥💪 – 183 ✅
⬜️ B. Cold reduces inflammation and swelling ❄️🧊 – 13
⬜️ C. Cold traps nutrients in damaged tissue 🚫💉 – 10
⬜️ D. Heat concentrates growth hormones 💧📈 – 1
Bottom line?
Turn up the heat. ♨️💪
Every runner loves seeing big watts on the screen. But what does that number actually mean?
Running power isn’t just “pace with extra decimals.” It’s a real-time snapshot of how much mechanical work your body is doing to move you forward, factoring in terrain, wind, and form efficiency.
So when your watch says 280 W, it’s capturing far more than speed. It’s showing a predicted balance between metabolic cost (how much energy you’re burning) and mechanical efficiency (how effectively you’re turning that energy into forward motion).
Why it matters:
Power ≠ Pace: Two runners can hold the same pace with totally different power outputs. The more economical one uses less energy to go just as fast.
Efficiency lives here: Over time, if your pace per watt improves, you’re literally becoming a more efficient machine.
Weather-proof training: Power cuts through noise from wind, heat, or hills—so you can target effort instead of terrain-limited pace.
💡 Bottom line: Pace tells you how fast you’re going. Power tells you why.
Don’t forget: You + Science = AWESOMENESS 😎
Yours in science,
Jonah
P.S. - We have a crew of 20,341+ nerds here who are running FAST using science.
Did you need running science advice or tips? 🏃♀️💨🧪
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