Achilles pain when running: why rest and stretch keeps failing and the simple plan that works

Quick note

This is general education about Achilles pain when running, not personal medical advice. If you’ve felt a sudden pop, noticed major swelling or bruising, or you can’t push off the ground properly, get assessed promptly.

Table of contents

• What this article will show you
• The rest–stretch–relapse loop
• The real cause of Achilles pain when running: load versus capacity
• Step 1: Make sure it’s actually Achilles
• Step 2: Remove spikes, not all load
• Step 3: Build capacity with progressive strength & length
• Step 4: Make footwear decisions deliberately
• Step 5: Judge progress by the next morning
• Common mistakes that keep the cycle alive
• When to seek assessment
• Frequently asked questions
• If you’re dealing with Achilles pain when running, remember this
• What next
• Related Reading

A corporate half-marathon runner sat in my clinic recently and said, “I’ve rested twice now. It keeps coming back.”

He runs at 6am before work. Training plan synced to his watch. Long runs locked into the calendar weeks in advance. He’s not reckless and he’s not ignoring warning signs.

When his Achilles started niggling, he did what sensible runners do. He stopped running for ten days. He stretched his calves at the kitchen bench. He rolled them out while watching the news. He eased back into short, flat runs.

It worked. For about two weeks.

Then the stiffness crept back. The ache returned after longer runs. The next-morning step out of bed came with that familiar tightness.

By the time he saw me, he wasn’t dramatic. He was irritated.

“I’m not doing anything stupid. Why does it keep happening?”

I’ve seen this pattern hundreds of times.

Achilles pain when running rarely behaves like a catastrophic injury. It behaves more like a negotiation. You back off and it settles. You return to normal training and it reminds you who’s in charge.

Rest can help. Stretching can feel responsible. But neither rebuilds tendon capacity in a structured way.

Most runners are given exercises. What they’re rarely given is a system. And without a system, the same load spike produces the same flare-up — again and again.

What this article will show you

If you’re dealing with Achilles pain when running and it keeps coming back, here’s what we’ll cover:

• Why rest and stretching often reduce symptoms but don’t solve the underlying issue
• What usually causes Achilles tendon pain from running
• The difference between mid-portion and insertional Achilles tendinopathy
• What to adjust in your training this week to stop flare-ups
• How to structure Achilles tendinopathy exercises properly
• How to return to running after Achilles pain without repeating the same cycle

If you’re looking for clarity rather than more random advice, this is where it starts.

If you want the structured version of this (with a weekly plan you can follow), grab Tendon Time.

The rest–stretch–relapse loop

Most runners with Achilles or heel pain do the responsible thing. They rest until symptoms settle. They stretch because someone told them tight calves are the cause. They ease back into running. It flares again. They repeat the process.

The frustrating part is that rest genuinely does reduce symptoms. Stretching often feels productive. Nothing about it seems irrational.

The problem isn’t effort. It’s structure.

You’ve been given activities — do these exercises — rather than a system that explains how to dose load and rebuild capacity.

The real cause of Achilles pain when running: load versus capacity

Achilles pain when running is a load–capacity mismatch.

Your Achilles tendon adapts to load. When the total load you’re placing through it — running volume, intensity, hills, speedwork, footwear changes, daily life stress — exceeds what it can tolerate right now, it reacts.

If you simply rest and stretch, you temporarily reduce load. But you don’t necessarily increase the tendon’s capacity to handle future load. So when you return to your previous training pattern, the same spike creates the same symptoms.

The goal is not to eliminate load entirely. The goal is to keep you training, as much as is sensible, while you remove spikes and deliberately rebuild tolerance.

Step 1: Make sure it’s actually Achilles

Before you commit to a plan for Achilles tendinopathy treatment, it’s worth confirming you’re in the right category.

Mid-portion Achilles tendinopathy typically presents with:

• Pain two to six centimetres above the heel bone
• Stiffness at the start of a run that warms up, then aches later or the next morning
• A tender or thickened section of tendon

Insertional Achilles pain, where the tendon attaches to the heel, often includes:

• Pain right at the back of the heel
• Irritability with deep calf stretching or steep hills
• Sensitivity from shoe collars pressing on the area

Plantar fascia pain is different again. It usually sits under the heel, feels more like a bruised spot, and is often worst with first steps in the morning. The mechanism to get plantar fasciitis pain is so similar to Achilles tendonitis they often happen at the same time. Unlucky!

If you’re unsure which bucket you’re in, guessing can prolong the problem. The most effective exercises and loading strategies differ depending on the presentation.

Step 2: Remove spikes, not all load

Most flare-ups trace back to one of a few predictable changes:

• A sudden jump in weekly volume
• Hills or speed sessions reintroduced too quickly
• Back-to-back run days without established tolerance
• A footwear change that alters heel drop or stiffness
• A “good day” where everything increases at once

The key rule is simple: don’t change five variables in the same week.

Practical adjustments for this week might include:

• Keeping runs flatter for seven to fourteen days
• Capping intensity temporarily
• Reducing total running load by 20–40 percent
• Being deliberate about what you do the day after a run

In my runner’s case, we didn’t stop running completely. We reduced hills, trimmed volume modestly, and kept the pattern predictable. The tendon settled because the spikes stopped.

Step 3: Build capacity with progressive strength & length

Achilles tendinopathy exercises work — when they’re structured and progressed properly.

A simple framework looks like this.

First, settle irritability and restore confidence. Isometric calf work can help some runners reduce pain sensitivity while maintaining training tolerance. The goal is consistency, not intensity.

Second, rebuild strength over weeks rather than days. Controlled, progressively heavier calf work forms the backbone of most programs. Progression should be guided by symptoms and function, not motivation.

Finally, reintroduce elastic loading and speed. Tendons need spring-like work to tolerate faster running. Skipping this stage is one of the most common reasons runners relapse.

If you remember nothing else from this section: strength first, spring second, speed last.

And if your Achilles tendon has been sore for more than six weeks, electrotherapy like shockwave is vital.

Step 4: Make footwear decisions deliberately

Footwear does not cause every Achilles problem, but it absolutely influences tendon load.

During a flare-up, avoid major shoe changes — particularly large shifts in heel drop or stiffness. If you do change shoes, change one variable at a time and monitor the next-day response.

Insertional cases, in particular, can become irritated when compression at the back of the heel increases.

We keep updating our list of the best running shoes for Achilles tendinitis.

Step 5: Judge progress by the next morning

Most runners assess progress based on how the run feels. A better metric is the following morning.

A simple traffic-light framework works well:

• 🟢Green: mild stiffness that settles quickly and does not worsen across days
• 🟡Yellow: increasing morning stiffness or persistent soreness over several days
• 🔴Red: sharp pain, limping, or clear deterioration

The aim isn’t to be overly cautious. It’s to prevent a slow drift into a multi-month issue.

Common mistakes that keep the cycle alive

• Resting until pain-free and then restarting at previous training loads
• Aggressive stretching when the tendon is already irritable
• Doing random exercises without structured progression
• Adding hills or speed before strength is rebuilt
• Changing shoes, training load, and exercises simultaneously

Each of these feels logical in isolation. Together, they often recreate the same flare.

When to seek assessment

Consider a structured assessment if:

• Symptoms persist beyond three to six weeks despite sensible load changes
• Pain is localised and worsening
• You’re unsure whether the issue is Achilles or plantar fascia
• You’re working toward a specific race or goal and need a clear return-to-run plan

A good plan should leave you feeling clear about what to do this week — and what improvement should look like.

Frequently asked questions

Not necessarily. Many runners can continue with modified load while rebuilding tendon capacity. The key is avoiding spikes and monitoring next-day response.

Most cases result from a load–capacity mismatch. Training load exceeds what the tendon can tolerate at that moment.

Nope! Just because something feels nice doesn’t mean that it is nice. We have written on this extensively in the past. Sore Achilles? Stretching could be making it worse.

Progressive calf strengthening, appropriately dosed and progressed, forms the foundation of most programs. The specifics depend on your presentation and running load.

With structured load management and progressive strengthening, meaningful improvement often occurs within six to twelve weeks. Inconsistent loading tends to prolong the issue.

Reintroduce volume before speed. Monitor next-day stiffness. Avoid stacking hills and speed too early. A gradual progression reduces the risk of relapse.

If you’re dealing with Achilles pain when running, remember this

Achilles pain when running is usually a load problem, not a damage problem. Rest settles symptoms; progressive strength rebuilds capacity. Judge progress by the next morning, not during the run itself.

Three weeks after we adjusted his load and rebuilt strength deliberately, my runner wasn’t obsessing over every step. Morning stiffness was predictable and improving. Hills were back, deliberately. Speedwork wasn’t — yet — and he understood why.

That’s the difference between random exercises and a system.

What next

If you want the structured version of this approach laid out step by step, start with Tendon Time.

If you want it tailored to your training week and your goal race, book an assessment and we’ll map it properly.

Related Reading

If this article resonates, these will help you go deeper, without repeating the same flare-up cycle.

• How to reduce Achilles pain in 48 hours Practical steps you can use immediately to calm an irritated tendon and stop a flare from escalating.
• 3 Achilles pain mistakes runners make (and how to dodge them) The subtle errors that keep the rest–stretch–relapse loop alive — and what to do instead.
• Achilles tendonitis pain: what to do today to feel better tomorrow A simple, structured approach for managing symptoms without completely shutting down training.
• The 6 best running shoes for Achilles tendonitis How heel drop, stiffness, and shoe design influence tendon load — and how to choose deliberately

About the Author

Tim Mulholland is a Melbourne-based podiatrist and founder of Pride Podiatry. He works with runners who are tired of guesswork — particularly those dealing with persistent Achilles pain, heel pain, and recurring injuries that never quite resolve.

Tim has a special interest in Achilles tendinopathy, load management, and helping runners return to training without repeating the same flare-up cycle. His approach combines clinical assessment with practical strength programming and clear load progression — so runners understand not just what to do, but why they’re doing it.

When he’s not in the clinic, you’ll find him lifting, running, or thinking about how to make injury management simpler and more systematic for everyday athletes. Quite literally it’s embarrassing how often I think about this stuff.