Achilles Tendon Stretching: Does It Actually Help Tendonitis?

If there's one piece of advice almost every person with Achilles tendonitis has received, it's this: stretch your calf.

It makes intuitive sense. The Achilles tendon connects your calf muscles to your heel bone. Tight calves must mean tension on the tendon. So stretch it out, right?

I've heard this from patients who got it from their GP, their physio, their personal trainer, and their running club. And it's advice that, in some cases, is making things significantly worse.

Let me explain what the evidence actually says — and why the answer isn't as simple as "stretch" or "don't stretch."

First, Understand What Kind of Achilles Problem You Have

Achilles tendinopathy — the clinical term for what's commonly called Achilles tendonitis — is not one single condition. It breaks into two main presentations based on where on the tendon the problem is located:

Mid-portion Achilles tendinopathy affects the tendon body, typically 2–6 cm above the heel. This is the most common type, especially in runners and active adults.

Insertional Achilles tendinopathy affects the point where the tendon attaches to the calcaneus (heel bone). You'll usually feel pain right at the back of the heel, sometimes with a bony bump (called a Haglund's deformity).

This distinction matters enormously when it comes to stretching. What's appropriate for one may actively harm the other.

The Case Against Stretching Insertional Achilles Tendinopathy

When you stretch your calf — think standing against a wall, heel dropped off a step — you're plantarflexing and then pulling back into dorsiflexion. This drags the Achilles tendon tight across the back of the heel bone.

For insertional tendinopathy, that compression is the problem. Research by Jill Cook and colleagues has repeatedly highlighted the role of compressive load at the insertion site as a driver of pain and pathology. When you stretch aggressively into dorsiflexion, you're doing exactly what the tendon can't tolerate: compressing it against the calcaneus.

I've had patients who came in doing daily calf stretching for months, frustrated that their pain wasn't improving. Within two weeks of stopping the stretching — and switching to appropriate loading — their symptoms started to settle.

If your pain is at the very back of your heel, stretching is likely one of the things keeping you stuck.

What About Mid-Portion Achilles Tendinopathy?

Here the answer is more nuanced. Mid-portion tendinopathy doesn't involve the same degree of bony compression, so dorsiflexion stretching doesn't carry the same risk. Some people find gentle calf stretching helpful for overall tissue mobility and reducing that "tight" sensation in the morning.

But here's what I want to be honest about: stretching alone does not treat mid-portion Achilles tendinopathy.

The tendon needs load — progressive, well-dosed loading — to adapt and recover. Stretching might feel like you're doing something, but it doesn't build tendon capacity. The research consistently shows that exercises like heavy slow resistance calf raises and isometrics produce the structural and symptomatic improvements that stretching simply cannot.

A 2015 study by Beyer et al. comparing heavy slow resistance training to eccentric-only training showed significant improvements in both tendon structure (on ultrasound) and pain. Neither protocol involved stretching as a primary intervention.

Why Stretching Feels Good Even When It Isn't Helping

This is something I discuss with patients a lot. Stretching can feel relieving in the moment — especially when the tendon is stiff first thing in the morning. The sensation of "releasing" the calf can temporarily reduce that tightness.

But feeling good in the moment doesn't mean you're progressing the condition. Tendons respond to mechanical loading, not to passive lengthening. The relief you get from a calf stretch is mostly a sensory experience, not a structural change in the tendon.

In fact, for irritable tendons, repeatedly provoking the tissue — even with gentle stretching — can maintain a heightened pain state without promoting adaptation.

So What Should You Do Instead?

This depends on where you are in your recovery, but the core principles apply across the board:

For insertional Achilles tendinopathy: Avoid deep dorsiflexion stretching entirely until the tendon is less irritable. Focus on isometric calf holds (foot flat, not dropped below heel level), and work with a clinician on a progressive loading program that respects the insertional anatomy.

For mid-portion Achilles tendinopathy: If light stretching feels helpful and doesn't increase your pain the next morning, it's unlikely to be harmful. But make it a small part of your routine — not the main event. The main event is your loading program.

For both types: Heel raises — done correctly, progressed appropriately — are the cornerstone of evidence-based Achilles rehab. Start with double-leg, add load, progress to single-leg. The tendon needs to be challenged to adapt.

A Note on Morning Stiffness and Stretching

Morning stiffness is one of the hallmark symptoms of Achilles tendinopathy. It's tempting to stretch it out first thing, but I generally advise against dropping into a deep stretch before the tendon has warmed up. Instead, start with gentle single-leg calf raises or a short walk to gradually load the tendon before asking it to tolerate stretch.

The stiffness usually settles within 10–20 minutes of activity. That's normal — it's one of the ways tendons behave differently from muscles.

The Bottom Line

Stretching your Achilles tendon is not universally good or bad — it depends on your specific presentation. But in my clinical experience, it's one of the most over-relied-on and under-questioned parts of Achilles tendonitis management.

If you have insertional pain, stop stretching into dorsiflexion. If you have mid-portion pain, don't rely on stretching as your primary treatment. In both cases, a loading-based program is the evidence-supported path forward.

Tendons respond to load. That's what they're built for. Give them the right kind, in the right dose, and they adapt.