Achilles pain has a specific personality. It’s stiff and sore for the first few minutes of a run, then eases off enough that you convince yourself it’s fine. It’s worst in the first ten steps out of bed the next morning. And it’s remarkably good at getting slowly worse over months while you tell yourself it’s manageable.
That pattern is the tendon telling you something concrete: it is being loaded beyond its current capacity, and it isn’t recovering between sessions. The good news is that Achilles tendinopathy in runners responds well to loading — and complete rest is one of the worst things you can do for it.
First: where exactly does it hurt?
This is the single most important question, because Achilles tendinopathy comes in two forms that require different early management.
Midportion tendinopathy sits roughly 2–6 cm above the heel bone, in the substance of the tendon. It’s the more common presentation in distance runners. You can often pinch it between finger and thumb and reproduce the pain. It usually has a visible or palpable thickening.
Insertional tendinopathy sits right where the tendon attaches to the heel bone. It’s frequently more stubborn, more common in older runners, and — critically — it’s aggravated by compression. Positions that drive the ankle into deep dorsiflexion, like heel drops off a step, tend to make it worse in the early stages, even though those same exercises are a mainstay for midportion cases.
This distinction is why generic internet advice fails so many runners. “Do eccentric heel drops off a step” is reasonable guidance for midportion tendinopathy and a good way to inflame an insertional problem. If your pain is at the very back of the heel, keep your early loading on flat ground, out of end-range dorsiflexion.
Why it happened
Tendons rarely fail from a single event. They fail from accumulation — a mismatch between the load you’re applying and the load your tendon is currently prepared for. Systematic review work on Achilles tendinopathy risk factors points toward prior lower-limb injury, calf weakness and reduced plantarflexion strength, and training-load error as the recurring themes.
Look back at the six to eight weeks before your symptoms started. Almost always something changed:
- Mileage climbed faster than your tendon adapted
- You added hills, speed work, or track intervals — all of which load the Achilles far more than easy running
- You switched to a lower-drop or more minimal shoe
- You returned from a break and resumed at your old volume
- Sleep, stress, or fueling changed while training stayed the same
None of this means you’re fragile. It means demand outran capacity. Both sides of that equation are modifiable.
Weekly load management
Load management is not rest. It’s controlling the dose so that adaptation can happen.
Start by knowing your actual weekly volume rather than estimating it, and treat large jumps as a deliberate risk rather than an accident. Remember that intensity counts as load: a week with the same mileage but a new tempo session and a hilly long run is a bigger week, and the Achilles is unusually sensitive to speed and incline. Build in genuinely easier weeks instead of climbing continuously. And track the things that change your tolerance without changing your mileage — sleep, life stress, fueling, and concurrent lifting.
Tendons also adapt more slowly than muscle. That’s the frustrating part, and it’s why patience with progression matters more here than almost anywhere else in running rehab.
Strength and mobility: the calf is the whole game
Meta-analytic evidence supports progressive loading as the core treatment for midportion Achilles tendinopathy, with multiple loading models — heavy slow resistance, eccentric protocols, and combined approaches — all producing meaningful improvement. The specific protocol matters less than whether the load is progressive and sustained.
What the tendon needs:
- Isometric calf holds — useful early, particularly on high-irritability days, and often analgesic in the short term.
- Heavy, slow calf raises through range — straight-knee (gastrocnemius) and bent-knee (soleus). Both are essential; the soleus is heavily involved in running and routinely neglected.
- Loaded, controlled lowering — the classic eccentric work for midportion cases, kept to flat ground rather than off a step if your pain is insertional.
- Posterior chain and hip strength — hamstrings, glutes, and hip extension capacity, because a weak chain upstream pushes more demand onto the calf.
- Foot intrinsics and toe flexor strength — small, frequently ignored, and genuinely relevant to force transmission.
Strength training has broad preventive value here too. Meta-analytic work in sports injury prevention has found strength training to be among the most effective interventions for reducing overuse injury, with a considerably larger effect than stretching.
On mobility: restricted ankle dorsiflexion is worth assessing and addressing, but do it thoughtfully. For insertional cases, aggressive end-range calf stretching often provokes symptoms rather than helping. Mobility work should be targeted at genuine restrictions, not applied as a reflex.
A useful benchmark for runners: can you perform single-leg heel raises through full range, on both sides, with comparable quality and endurance? Most runners with Achilles pain cannot, and closing that gap is the substance of the rehab.
Keep running — but change the running
Randomized trial evidence in Achilles tendinopathy supports continued running activity during rehabilitation when it’s guided by a pain-monitoring model, rather than blanket rest. Deconditioning has its own costs, and returning to running with a detrained tendon reproduces the original problem.
What that looks like in practice:
- Run at a volume that keeps symptoms tolerable, using pain during and after as your guide rather than pushing to a fixed schedule.
- Judge by the 24-hour response. Morning stiffness the next day is your most honest signal. If it’s worse than the previous morning, yesterday’s session was too much. If it’s the same or better, you’re in the right dose.
- Cut the aggravating variables first, not mileage indiscriminately. Hills, speed work, and track sessions load the Achilles disproportionately — removing those alone often calms things while preserving most of your volume.
- Break longer runs into shorter ones. Two short runs generally provoke a tendon less than one long one.
- Avoid abrupt footwear changes mid-rehab. A slightly higher heel drop is sometimes better tolerated temporarily, particularly in insertional cases.
- Use cross-training to hold aerobic fitness, while understanding it isn’t preparing the tendon for impact.
The step almost everyone skips: plyometrics
Here’s where rehab commonly stalls, and where recurrence comes from.
The Achilles is an elastic energy store. During running it stretches and recoils dozens of times per minute through the stretch-shortening cycle, handling forces well above body weight at high rates of loading. Heavy slow calf raises build tendon capacity and strength — but they train force production at a speed that has almost nothing in common with running.
If you go from heavy calf raises directly to your old mileage, you’ve asked a tendon that’s only been loaded slowly to suddenly perform fast, repeated elastic work. That’s the gap where re-injury lives.
The bridge is graded energy-storage loading, progressed in order:
- Bilateral, low-amplitude — pogo hops, small vertical hops, skipping in place
- Higher-amplitude bilateral — jump squats, bounding, box jumps with controlled landings
- Single-leg — single-leg hops in place, then forward, then lateral
- Directional and reactive — hopping with faster ground contact times, decelerative work, change of direction
Progress one stage at a time, and check the next-morning response before advancing. Only after you’re tolerating single-leg energy-storage work well does full running volume make sense.
When to get it assessed
Get seen if pain has persisted beyond two to three weeks despite reducing volume, if morning stiffness is worsening week over week, if you’re altering your gait to accommodate it, or if you’ve had recurrent episodes.
Seek prompt medical attention for sudden severe calf or heel pain, a sensation of being struck or a pop in the back of the leg, or a marked inability to push off — these can indicate tendon rupture. Also mention it to your physician if you’ve recently taken fluoroquinolone antibiotics, which are associated with tendon injury.
In California, you can be evaluated and treated by a physical therapist without a physician’s referral for up to 45 days or 12 visits, whichever comes first.
Frequently asked questions
Can I keep running with Achilles tendinopathy?
Usually yes, at a modified volume and intensity, guided by pain response. Trial evidence supports continued activity under a pain-monitoring model over complete rest.
How long does Achilles tendinopathy take to heal?
Tendons adapt slowly. Meaningful improvement commonly takes three months or more, and longstanding cases can take longer. Consistency of loading matters more than intensity.
Should I stretch my calf?
Sometimes. For midportion cases, addressing genuinely limited dorsiflexion can help. For insertional cases, end-range stretching often aggravates symptoms through compression at the attachment.
Do heel lifts help?
They can reduce tendon load short-term and are sometimes useful early, particularly for insertional pain. They’re a symptom management tool, not a fix — the tendon still needs progressive loading.
Is it tendinitis or tendinopathy?
Tendinopathy is the more accurate term. The problem is generally degenerative and load-related rather than primarily inflammatory, which is why rest alone tends not to resolve it.
This article is general education, not individual medical advice. If you’re dealing with persistent Achilles pain, get assessed by a qualified clinician.
Strike Physiotherapy & Performance is a cash-pay, one-on-one physical therapy and performance clinic in North Hollywood, working with distance runners across the San Fernando Valley. Speak with a PT — no referral needed.
References
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