🏃♂️ Could Running Less During Your Taper Be the Secret to Your Fastest Marathon Yet?
Estimated read time: 3.38 minutes (aka how long it takes me to start dreaming about the finish line Pizza 🍕)
Hey Performance Nerds! Jonah here. 🤓
Could running less for three weeks actually make you faster?
The final 21 days can make or break your marathon. Too many runners lose minutes by botching their taper, ruining 16 weeks of hard training! 🚨
But here’s where science saves us:
The right taper can make you ≈ 2.6 % faster. For a 3-hour marathoner, that’s nearly a free 5-minute PR without a single extra mile. 🎯
Today, you’ll learn exactly how to nail your taper:
The science behind why tapering works (and why it’s worth minutes)
Your exact taper blueprint to arrive sharp—not stale
The 3 deadly taper mistakes that ruin race day (and how to avoid them)
How to tailor your taper based on your training volume
I originally shared this a while back, but with so many of you gearing up for New York, it felt right to bring it back, now updated with the latest science on tapering to support you.
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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.
Why Your Taper Can Make (or Break) Your Marathon 🧪
A good taper can make you faster without adding a single extra mile.
Here’s what happens when you ease off:
Glycogen Rebuild → Full Fuel Tanks.
Your muscles restore their carbohydrate stores so you’ve got energy for the final 10 K.
Muscle Repair → Fresh Legs.
Micro damage from training is repaired, so you hit race day feeling fresh
Hormonal Reset → Better Endurance.
Cortisol drops, testosterone rebounds, boosting your strength and endurance.
Circulatory Boost → More Oxygen Delivery.
Blood volume and red-cell mass may even increase slightly: helping your heart pump more efficiently.
📊 Research shows a 3-week taper improves marathon performance by ≈ 2.6 % (~5 min for a 3:00 marathoner).
And some data suggests women may benefit even more—up to 3.1 %.
Think of tapering like charging your phone before a big run. You wouldn’t start a 3-hour run with your battery at 20%, right? (Especially if Taylor Swift is on your playlist! 🎶😅)
Find Your Perfect Taper Timeline ⏰
Warning: The wrong taper could cost you minutes on race day. But, the optimal taper length varies by individual.
The science: an exponential taper (cutting total mileage by 40–60 % over 2–3 weeks, with the biggest drop early) can boost performance by 2–5%. 🚀
Exponential Taper Basics: Notice the sharp cut in volume early on. Exponential ice cream consumption not included (unfortunately—I wish 🍦😅)
📆 Your Week-by-Week Taper Blueprint
Week Out | % of Peak Mileage | Focus | Key Reminder |
|---|---|---|---|
3 Weeks | 70–80 % | Maintain rhythm, shorten long run | Keep 1-2 workouts, drop total mileage |
2 Weeks | 50–60 % | Freshen legs | Stick to your usual running frequency |
Race Week | 30–40 % | Recover + sharpen | Practice fueling, visualize race plan |
Pick Your Perfect Plan 📅
High-Mileage Runners (60+ mi/week) 💪
Go for a 2-3-week taper to allow deeper recovery from accumulated fatigue.
Keep frequency steady but reduce long-run distance and total volume
Moderate Mileage (40–60 mi/week) 🏃♂️
A 2-week taper keeps you sharp without losing aerobic fitness
Maintain intensity: 1–2 shorter race-pace segments each week.
Your Week-by-Week Blueprint 📅
Your taper strategy, customized for your weekly miles—because one size doesn’t fit all. I think I forgot to include the pizza strategy on this… clearly an oversight 🍕😅.
Why One Size Doesn’t Fit All 🧬
Recovery Speed: Fast recoverers may prefer shorter tapers
Bounce back quick after big weeks? Go short.
Prone to lingering fatigue or heavy mileage? Stick with three weeks.
Training History: Experienced runners handle volume better
Personal Response: Everyone adapts differently, pay attention to how you feel
Pro tip: Stick to your usual running frequency, just shorten the runs. It’s like watching one Netflix episode instead of bingeing the whole season. 📺
The 3 Deadly Taper Mistakes (and How to Avoid Them!) 🙅
Most runners sabotage their marathon during the taper.
Trust me, I’ve made them all in the name of science and paid the price on race day. (Still treated myself to ice cream after, though. #SmallWins 😅)
⚠️ Mistake #1: Going Too Easy = Sluggish Legs on Race Day
The Problem: Cutting all intensity during your taper can leave your legs sluggish on race day. It’s like letting your car sit idle before a road trip, you need to keep the engine warm.
Fix It:
Include 2–3 short race-pace segments each week
Keep 1–2 workouts, but cut the volume by 40-60%
Example: Instead of 6x1 mile at race pace, do 3x1 mile
Mistake #2: Panic Training 😰
The Problem: Adding “just one more” long run or speed session during taper week increases fatigue.
Fix It:
Trust your training, your fitness is already built
Follow your taper plan
Remember: Being 10% undertrained beats overtrained
Mistake #3: Changing Your Routine 🎯
The Problem: Race week is NOT the time to try new shoes, new fuel, or new foods. Even small changes can lead to race-day disasters.
Fix It:
Stick to your usual diet (goodbye, spicy tacos, maybe even the ice cream. I know, it’s sad)
Maintain your normal sleep schedule
Use only trusted gear, don’t test those flashy TikTok-famous Nikes now!
In taper week, “boring” is elite behavior.
Practical Summary (TL:DR for the Non-Science Nerds)
Nail your taper, gain 2.6–5 % performance — that’s 5–10 free minutes for most marathoners.
High mileage (60+ mi/week) → 3-week taper.
Moderate mileage (40–60 mi/week) → 2-week taper.
Keep 1-2 race-pace efforts weekly to stay sharp.
Cut volume, not frequency.
Stick with familiar fuel and gear.
Trust your training — rest is the final rep.
💬 One last thing before you go.
If you’re heading into New York or wrapping up your fall marathon block and want to double-check your taper plan—hit reply.
I read every message and I’m here to help however I can.
Keep those carbs high,
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.
During a long race when you don’t take in carbs, what happens to your body’s fuel mix as fatigue sets in?
- A. You burn more fat as glycogen stores drop — but your pace might slow because fat produces energy more slowly 🥑⏳
- B. You keep burning all carbs, just from liver glucose instead of muscle glycogen 🍯🏃♂️
- C. You switch 100% fat-burning, becoming more efficient once glycogen runs out 🔥🚀
- D. You start breaking down protein for most of your energy needs 🍗😬
🏃♂️ Stryd Training Tip — Spot Fatigue Before It Costs You Miles
Every long run teaches you something, if you know where to look.
The Stryd Duo lets you see fatigue in real time by measuring how your running mechanics change as you tire.
As fatigue builds, even small changes can reveal when your form starts to break down, long before you feel it.
Why it matters:
Detect fatigue early: Watch how ground contact time, leg stiffness, and impact shift through your long run.
Prevent overreaching: Spot the exact point where efficiency fades so you can adjust training load or fueling.
Track recovery: Compare asymmetry trends week to week to see if your body’s truly adapting.
💡 Bottom line: The Stryd Duo turns every long run into a fatigue lab, helping you see when efficiency fades and train smarter before fatigue slows you down.
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.
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