Free Speed: How to Use Caffeine to Shave Minutes off Your Marathon
Estimated read time: 3.6 minutes (about the amount of time you waste thinking up a funny Strava title for your morning run). 😉
Hey Performance Nerds! Jonah here. 🤓
☕️ Caffeine can boost endurance by 2–4%, yet most marathoners get it wrong.
It peaks in your bloodstream 45–60 minutes after you take it, and smart mid-race top-ups can help you hold pace when others fade. But misuse it, and you’ll end up with jitters, GI distress, or a wasted boost.
Today you’ll learn how to turn caffeine into free speed:
⚡ The exact pre-race dose by bodyweight that science backs
⏱️ When and how to top-up mid-race so you stay sharp through mile 20+
🛡️ Safety, side effects, and practice rules so you get the benefit without the crash
👉 One of my first guides, now updated with the latest on caffeine timing, habitual use, and in-race top-ups, just in time to help you crush the fall majors.
🧬 Performance Sponsors:
🚀 Train Harder. Recover Smarter.
SiS—the same science-backed fuel trusted by Olympic marathoners—is now sponsoring Marathon Science.
From hydration mixes 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.
🧠 The Science: Why Caffeine Actually Works
Most runners think caffeine works by burning more fat. While it does a little, the real performance boost comes from the brain.
Caffeine blocks adenosine, the chemical that makes you feel tired. With adenosine blocked, you:
🚀 Feel less fatigue
🛡️ Perceive less effort and pain
⚡ Stay sharper and pace better
Caffeine also boosts adrenaline and endorphins, keeping you more alert while blunting the pain signals that normally slow you down.
Recent research shows caffeine’s real benefit is in the brain, not the muscles, which is why it remains one of the most reliable, legal performance boosters in endurance sport.
☕ The Pre-Race Formula: Exactly How Much Caffeine You Need
Research shows the sweet spot is 3–6 mg per kilogram of bodyweight, taken about 60 minutes before your race.
If you’re caffeine-sensitive or prone to jitters, stick to the low end (≈3 mg/kg).
If you’ve used caffeine comfortably before, you can push toward the higher end (≈6 mg/kg).
For me: at 170 lb (77 kg), that’s about 230–450 mg, or roughly 2–3 cups of coffee. (One cup can range anywhere from 70–140 mg, depending on brew strength.)
And yes, after 450 mg, even Augie — my dog — gets sick of me talking his ears off.
📊 Caffeine Cheat Sheet by Bodyweight
Bodyweight (kg) | Bodyweight (lbs) | Low Rec | High Rec |
|---|---|---|---|
50 | 110 | 150 mg | 300 mg |
55 | 121 | 165 mg | 330 mg |
60 | 132 | 180 mg | 360 mg |
65 | 143 | 195 mg | 390 mg |
70 | 154 | 210 mg | 420 mg |
75 | 165 | 225 mg | 450 mg |
80 | 176 | 240 mg | 480 mg |
85 | 187 | 255 mg | 510 mg |
90 | 198 | 270 mg | 540 mg |
95 | 209 | 285 mg | 570 mg |
100 | 220 | 300 mg | 600 mg |
105 | 231 | 315 mg | 630 mg |
110 | 243 | 330 mg | 660 mg |
⚠️ Pro tip: Always test your caffeine plan in training. What works on paper can backfire if you try it for the first time on race day.
Caffeine content varies a lot, so on race day make sure you know your dose. Too little wastes the boost, too much risks jitters or GI issues.
🧪 Example Caffeine Sources
Caffeine Source | Approx. Caffeine (mg) |
|---|---|
Starbucks Tall Coffee | ~260 |
Celsius | ~200 |
Monster | ~160 |
Brewed Coffee | ~100 |
SiS GO Caffeine Shot (60ml) | 150 |
SiS Beta Fuel + Nootropics Gel (60ml) | 200 |
Red Bull | ~80 |
Espresso | ~70 |
⏱️ How to Use Caffeine During Your Race
One of the biggest mistakes marathoners make is waiting until the late miles to take caffeine.
By then, it’s too late, the boost arrives after the finish line instead of when fatigue hits.
Here’s what matters:
Caffeine kicks in within ~15 minutes and peaks at 45–60 minutes.
Target 100–200 mg total in-race, depending on your tolerance.
Best strategy: take a caffeinated gel around the 60-minute mark so the effect lands during the hardest part of the race.
👉 If you save caffeine until mile 20, all you’ll get is extra energy for the after-party. 💃
My strategy: I use SiS Beta Fuel gels (40 g carbs each) every 30 minutes, with a caffeinated gel at 60 minutes.
That timing keeps caffeine high through the final 10K when most runners fade.
📊 Sample In-Race Caffeine Plan (3-Hour Marathon)
Time (Min) | Gel Type | Caffeine | Source |
|---|---|---|---|
30 | Non-Caf | 0 | SiS Beta Fuel Gel |
60 | Caf | 200 mg | SiS Beta Fuel + Nootropics Gel |
90 | Non-Caf | 0 | SiS Beta Fuel Gel |
120 | Non-Caf | 0 | SiS Beta Fuel Gel |
150 | Non-Caf | 0 | SiS Beta Fuel Gel |
180 | Finish | – | – |
⚠️ Pro tip: Some runners split their in-race caffeine (60 and again at 90–120 minutes) to maintain steady levels in longer marathons, especially closer to 4 hours.
But the 60-minute bolus is the simplest and most effective approach for most runners.
📆 Do You Really Need to Quit Coffee Before Race Day?
Many runners think cutting coffee the week before a marathon will “reset” sensitivity.
You don’t need to. Research shows regular caffeine use doesn’t reduce performance benefits on race day.
Trust me, even Augie (my dog) can’t handle me without my morning coffee.
🎯 Practical Summary
3–6 mg/kg of bodyweight about 60 minutes pre-race
Use sources where you know the exact caffeine amount
100–200 mg during the race, ideally in the first 1/3–1/2
Gels, pills, or chews — all work, just practice in training
No need to cut caffeine the week of the race
Always practice your caffeine plan in training — never try it for the first time on race day.
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.
Why might wearing super shoes for every run (not just workouts and races) backfire long-term?
- A. They reduce ground contact time, limiting aerobic development 🏃♂️⌛
- B. They’re too unstable at slower speeds, raising injury risk 🌀🚫
- C. They offload foot and lower leg stress, potentially weakening those tissues over time 🦶📉
- D. They shift mechanics so much you can’t train efficiently at easy paces 🔄🐢
Last Week’s Results: The Engine Upgrade 🔧❤️
VO₂ max gets tossed around like it’s about lungs or fancy breathing drills, but the real limiter is much deeper. Most of you got this one right!
The correct answer?
B. A stronger heart pumping more blood per beat (stroke volume) ❤️ ✅
Bigger lungs help, stronger legs matter, but VO₂ max ceiling rises when the heart adapts to push more oxygen-rich blood with every contraction. That stroke volume boost is what separates trained runners from casual joggers, it’s the real horsepower upgrade.
Here’s how the votes shook out:
⬜️ A. Bigger lungs that move more air 🌬️ – 13
🟩 B. A stronger heart pumping more blood per beat (stroke volume) ❤️ – 135 ✅
🟨 C. Stronger leg muscles that burn less oxygen during runs 🔥 – 43
🟨 D. Improved running form that wastes less energy 🏃♂️ – 31
Bottom line?
Want a higher VO₂ max? Build a bigger pump. Your heart’s stroke volume—not your lungs—is a true engine of endurance. 🚂💨
🏃♂️ Stryd Training Tip — Consistent Data Indoors and Out
Treadmill belts lie, GPS drops outside, and your splits rarely line up. Stryd fixes that. By measuring your stride directly, it delivers true pace, distance, and power anywhere you run.
Why it works:
Direct stride measurement: Accurate pace and distance indoors or out.
Universal power metric: Compare workouts apples-to-apples with watts.
No calibration required: More reliable than most treadmill displays.
💡 Bottom line: Trust Stryd as your data source and your training stays seamless and accurate year-round — indoors or outdoors. No more gaps in your log when winter pushes you inside.
Don’t forget: You + Science = AWESOMENESS 😎
Yours in science,
Jonah
Please email me directly if you’re interested in references for this week!