Chronic Tendinopathy in Runners — And How Tendons Actually Heal

If you’re a runner who has been dealing with stubborn Achilles pain, nagging hamstring soreness, or a patellar tendon that never seems to settle, you’re not dealing with “inflammation. ”You’re dealing with chronic tendinopathy — a tendon that has failed to heal properly after being overloaded.

The good news? Tendons can recover. The bad news? They don’t heal the way most runners think.

Let’s break it down.

What Is Chronic Tendinopathy?

A tendon is the thick, fibrous tissue that connects muscle to bone. It’s designed to:

• Store elastic energy

• Transmit force

• Tolerate massive repetitive load

When running volume, intensity, or mechanics exceed what the tendon can tolerate, small areas of the tendon begin to fail.

In early stages (reactive tendinopathy) there is swelling and pain. In chronic stages, something more important happens:

The tendon’s collagen structure becomes disorganised, weaker, and less stiff.

This is not inflammation .It is tendon degeneration.

That’s why:

• Anti-inflammatories don’t fix it

• Rest alone doesn’t cure it

• Ice and massage only give temporary relief

You can calm pain, but unless the tendon remodels, the problem stays.

Why Runners Get Chronic Tendinopathy

Running places huge repetitive loads through tendons:

• Achilles → 6–8× bodyweight every stride

• Patellar tendon → absorbs braking forces

• Hamstrings → decelerate the leg at high speed

Chronic tendinopathy develops when load exceeds the tendon’s ability to adapt.

Common triggers include:

• Sudden mileage increases

• Speed work without preparation

• Hills

• Changing shoes

• Running through pain

• Poor recovery

• Weak or poorly coordinated muscles upstream

Over time, the tendon loses its ability to store and release energy efficiently — so every run creates micro-damage instead of adaptation.

How Tendons Actually Heal

This is where most rehab goes wrong.

Tendons do not heal by rest. They heal by mechanical loading — done correctly.

Tendon cells respond to load by:

• Producing new collagen

• Aligning fibres

• Increasing stiffness and strength

But they only do this when the load is:

• Heavy enough

• Slow enough

• Consistent enough

Random stretching, massage, and light exercises do not send a strong enough signal.

This is why progressive loading is the foundation of tendon rehab.

The Three Phases of Tendon Recovery

1. Calm the Pain

Before loading, pain must be under control.

This does NOT mean zero pain — it means pain is stable and not flaring up day to day.

This usually involves:

• Reducing running volume or intensity

• Avoiding hills and speed work

• Using isometric exercises (static holds) to reduce pain

Pain reduction allows the tendon to tolerate loading again.

2. Restore Tendon Strength

This is where real healing begins.

Tendons need heavy, slow resistance.

Examples:

• Slow calf raises for Achilles

• Slow squats and leg presses for patellar tendon

• Slow hamstring curls or hip hinges for proximal hamstrings

The key:

• Slow

• Heavy

• Minimal momentum

This tells the tendon: “You need to become stronger and stiffer.”

Over weeks, collagen reorganises and tensile strength improves.

3. Re-Teach the Tendon to Run

Running is not slow — it’s elastic and explosive.

Once strength is restored, the tendon must relearn to:

• Store energy

• Release energy

• Tolerate impact

This phase includes:

• Hopping

• Skipping

• Plyometrics

• Gradual return to running

Without this phase, many runners relapse when they return to full training.

Why Rehab Fails So Often

Most runners either:

• Rest too much

• Load too little

• Or return to running too fast

Tendons adapt slowly — but when trained correctly, they become extremely resilient.

A tendon that has healed properly is often stronger than before.