Knowledge Bomb 💣: #1 Predictor of Running Injuries

The best aren’t getting better on their own, they’re getting better because they are being coached.

🧬 The Science — When Load Outpaces Capacity

Most running injuries come down to one simple truth: the stress you put on your body outpaces what it can handle.

The catch? Different tissues adapt at different speeds:

 • Muscles: bounce back in 2–3 days.

 • Tendons & bones: take weeks, sometimes months, to fully adapt.

That’s why you might feel fresh after a few days off—but your tendons could still be repairing from training you did weeks earlier.

Take a sudden 50% leap in your long run? Your muscles keep up, but your connective tissues can’t, leaving small cracks that grow faster than they can heal.

Think of it like sun exposure: a little daily builds a tan, one huge blast leaves you burned.

Slow, steady increases let every system adapt together. Overshoot with one “epic” session, and you risk tipping the balance.

And remember—lack of sleep, stress, or poor recovery lowers your capacity even further. Your body doesn’t follow a calendar. Listen first, schedule second.

📊 The Spike That Trips Runners Up

The surprise isn’t that training load matters—it’s how it shows up.

What researchers found:

• Weekly mileage jumps? Not a strong predictor of injury.

• Single-session spikes? Big red flag.

  Example — The Long Run Spike

• <10% increase: Usually safe, within tolerance.

• 10–50% increase: 64% higher chance of injury.

• >100% increase: 128% higher chance of injury.

So if your longest run in the last month was 10 miles, then you jump to 15 on a Saturday group run—that’s a 50% leap, and your odds of breaking down rise dramatically.

Mileage still builds fitness long term, but the single-run jump seems to be the sharper injury trigger.

🎯 How to Progress Without Breaking Down

Here’s the simple framework: never increase your long run by more than 10–15% from your recent longest run in the past month.

8-Week Build Example (starting longest run = 10 miles)

See the rhythm? Controlled increases, strategic drop-backs, and no surprises.

⚡ Your Action Plan

• A single long run >10% beyond your recent best = ~64% higher risk of injury

• Doubling your longest = ~128% higher risk

• Weekly mileage increases alone weren’t the strongest predictor

• Muscles adapt in days, tendons/bones in weeks → respect the mismatch

• Stick to the 10–15% rule for your long run

• Tired, stressed, or underslept? Dial it back

You can’t eliminate every injury factor (nutrition, stress, random bad luck all play roles). But you can avoid one of the biggest self-made mistakes: huge single-run jumps.

Patience beats hero workouts every time. Build resilience, not just distance.

✏️ Editors Note

The Coaches Coach newsletter was originally designed as a space for coaches to learn—not just about leadership and soft skills, but about the science of performance. Over time, our content naturally leaned more toward leadership and people management, which meant we drifted a little from our original plan.

To bring that balance back, we’re introducing a monthly feature: Knowledge Bomb 💣.

Each post will tackle real questions around performance, injury, and sports science—practical insights drawn from years of experience working alongside some of the best in professional sport.

In short: leadership and coaching wisdom will stay, but you’ll also get hard-hitting, evidence-based answers that help you elevate performance.

Allow Us To Become Your Coach.
Join Our SECOND SET OF EYES Programme.