Achilles Tendinopathy: Why Rest Alone Isn’t the Answer
If you’ve ever been told to “just rest it” for an Achilles problem, you’re not alone. It’s one of the most common pieces of advice given to runners - and one of the least helpful.
Achilles tendinopathy nags, lingers, and feels better after a warm-up only to come back the next morning. And when people finally seek help, they’re often told to stop running and wait it out. Here’s the problem: rest doesn’t fix a tendon. As a sports physio working with runners every week, here’s what you actually need to know.
What Is Achilles Tendinopathy?
The Achilles tendon connects your calf muscles to your heel bone. Tendinopathy is an overuse condition where the tendon becomes painful, stiff, and loses its ability to tolerate load. Despite the old term “tendinitis”, it’s not a straightforward inflammatory condition - it’s a breakdown in the tendon’s internal structure from repeated stress without adequate recovery.
There are two main types: midportion (pain a few centimetres above the heel, most common in runners) and insertional (pain right at the heel bone, which behaves slightly differently and needs a modified approach).
How Common Is It?
Very. Between 6 and 10% of runners are affected at any one time, and the lifetime risk for middle and long-distance runners is as high as 52%. Runners are around ten times more likely to develop it than inactive people, with peak incidence between the ages of 40 and 59.
Why Rest Doesn’t Work.
Rest reduces pain in the short term - which is why it feels like the right call. But here’s the cycle it creates: you rest, feel better, return to running, and the pain comes straight back. Sometimes worse. A tendon needs mechanical load to adapt and repair. Remove that load completely and the tendon doesn’t heal - it becomes less tolerant of the stress it will face when you start running again. The irritation settles, but the underlying problem remains untouched.
The 2024 Clinical Practice Guidelines from the Academy of Orthopaedic Physical Therapy are clear: complete rest is not necessary, and patients should continue activity within their pain tolerance. This is the current evidence-based standard of care - not a niche opinion.
What Actually Works: Loading the Tendon
The gold-standard treatment is progressive tendon loading - a structured exercise programme that gradually increases the demand placed on the tendon. Research shows meaningful improvements as early as two weeks in, and exercise significantly outperforms a “wait and see” approach across multiple systematic reviews.
The main approaches used in clinic are:
Isometric calf holds - holding a loaded position without movement. Useful in the early, irritable stage as they reduce pain quickly with minimal stress on the tendon.
Eccentric calf raises - the classic Achilles rehab exercise, performed slowly on a step. A strong evidence base built over decades.
Heavy slow resistance (HSR) training - working both the lowering and raising phase with higher loads, performed slowly. At least as effective as eccentric-only programmes, and often easier to stick to.
The right approach depends on your stage of tendinopathy, pain levels, and training goals. A sports physio will tailor a programme to you - not hand you a generic protocol.
Can I Keep Running?
Usually, yes - but it needs managing. A simple guide: pain of 3/10 or less during or after a run is generally acceptable, as long as it settles back to your baseline within 24 hours. If it doesn’t, you’ve done too much. This isn’t a green light to grind through pain. But moderate, well-managed discomfort during rehab is normal and expected. A sports physio can help you adjust your training load so you keep moving without going backwards.
What Else Contributes?
Achilles tendinopathy is rarely caused by one thing. A good assessment will look at calf strength and endurance (weakness is one of the most consistent findings), recent training load and any spikes in mileage, running biomechanics, and footwear. Understanding why the tendon became overloaded is just as important as treating it.
How Long Does Recovery Take?
I’ll be straight: Achilles tendinopathy takes time - typically 3 to 6 months for full return to unrestricted running. But most people notice significant improvement well before that, and the vast majority recover fully without surgery or injections. Starting the right rehab early, rather than cycling in and out of rest, is the biggest factor in how quickly you get there.
The Bottom Line
Rest might ease your Achilles pain short-term, but it won't fix it. Tendons need load to adapt, and the best thing you can do is start a structured, progressive loading programme as early as possible.
Stuck in the rest-return-repeat cycle? Not sure whether what you're feeling is normal tendon irritation or a sign you're doing too much?
Sometimes knowing how to load safely is the hardest part. At Pace Physio, our Stride Strong service gives you an in-depth assessment of your strength, mobility, and running form, with a bespoke plan built around what your Achilles specifically needs to recover and stay strong.
Get in touch or book an appointment and let us help you get back to running, injury free.
