If you're reading this, you've probably been at it for a while. You've done the calf raises, you've stretched, and you've rested when it flared up and started again when it settled down. Months later, the tendon still hurts. Maybe not as bad as before, but enough that you don't trust it.
Achilles problems are stubborn, but when rehab has truly stalled, it's almost always one of a handful of fixable things. These are the five I see most in clinic, roughly in order of how often they turn out to be the problem.
One quick note on names, because they cause a lot of confusion. You may have been told you have Achilles tendinitis, Achilles tendonitis, or Achilles tendinosis. Most clinicians now use tendinopathy as the umbrella term, because the problem usually isn't active inflammation the way "-itis" implies. It's a tendon that's been asked to do more than it's had a chance to recover from, with gradual changes to the tissue itself. Different labels, same stubborn problem, and everything below applies regardless of which word you were handed.
01Your loading is under-dosed
This is the big one. Tendons adapt to meaningful load, and what counts as meaningful is usually far more than people are doing. Three sets of gentle calf raises, once a day, with bodyweight, forever, is a maintenance dose at best. The tendon has no reason to change.
A lot of stalled rehab is just a plateaued program. The exercises never got heavier or harder. If your routine looks the same as it did two months ago, the tendon hasn't had a reason to adapt in two months.
02There's no progression plan
This one is closely related to the first, but it's a separate issue. Many people are working hard, but randomly. A little of this exercise, a little of that one from a YouTube video, with intensity decided by how the tendon feels that day. Tendon rehab rewards boring consistency along a planned path, from slow and heavy toward faster and springier, over months. Random effort gets random results.
03You never rebuilt the spring
This is the stage that almost every home program and clinic handout skips entirely. The Achilles isn't just a rope, it's a spring. Its whole job in running and jumping is to store and release energy rapidly. Slow, heavy strength work is essential, but it doesn't train that elastic quality.
So people complete their strength phase, feel fine walking around, and return to running. Then the tendon fails at the exact quality that was never trained. If your rehab never included a gradual reintroduction of hopping, bouncing, and faster loading, you didn't finish rehab. You stopped two-thirds of the way through.
04You're loading the wrong tissue, or the wrong zone
"Achilles pain" isn't one condition. Insertional pain (right at the heel bone) and mid-portion pain (higher up the tendon) respond to different strategies, and the famous rehab protocols for one can actively aggravate the other, with deep heel drops being the classic example. Additionally, sometimes the pain generator isn't the Achilles at all, but a neighboring structure that presents very similarly.
If you've been diligently following a generic protocol and reliably getting worse, this is the first thing I'd question. I've written a full guide on the insertional vs. mid-portion difference. It's a five-minute read that might explain your last six months.
05The foundation under the tendon is weak
The Achilles doesn't work alone. It sits in a chain that starts with the foot, and if the foot is weak and poorly connected to the ground, the tendon absorbs load it was never meant to handle alone, every single step. Rehab that trains the tendon while ignoring the foot leaves the weakest link untouched. (More on that in why your feet are weak.)
How much pain is normal along the way?
This is the question I get more than any other, and it's usually what pushes people into one of two ditches: quitting at the first twinge, or grinding through pain that should have been a stop sign.
Loading an irritated tendon isn't supposed to be completely painless. Mild to moderate discomfort during and shortly after your exercises is generally expected, and within reason it's acceptable. You're asking the tendon to adapt. Work light enough to feel nothing at all is usually work light enough that the tendon has no reason to change.
Severe pain is a different signal entirely. Sharp, intense, or steadily escalating pain isn't a badge of effort and isn't something to push through. Pain that climbs set after set means stop, not continue.
The more useful measure isn't what you feel during the exercise, it's what happens afterward. As a general principle, discomfort that settles back toward your normal baseline within about a day, with a tendon that isn't noticeably more stiff or sore the next morning, suggests the load was tolerable. Symptoms clearly worse the following day, or building across the week, suggest you've gone past what the tendon could handle. That's usually a reason to pull the load back a notch, not to abandon the plan entirely.
The honest summary
What's not on this list: your age, your genetics, or the idea that some tendons just never get better. In my experience, those are the explanations people settle for after months of under-dosed, unstructured rehab. The fix, in nearly every stalled case I see, looks the same: a progressive plan, followed for months, that starts from the ground and finishes with elasticity.
You can absolutely build that with a good clinician. If you're doing it on your own, the problem is that free internet advice gives you exercises but not structure. As covered above, structure is usually the thing that was missing.
Common questions
How long should Achilles tendinopathy take to get better?
Longer than most people expect. Stubborn cases are generally measured in months rather than weeks, and it's common for meaningful change to take somewhere in the range of three to six months of consistent, progressive loading. The trajectory matters more than the calendar: if you're gradually tolerating more load month over month, it's working, even when day-to-day pain fluctuates.
Should I just rest it completely until it stops hurting?
Complete rest usually backfires. It calms symptoms in the short term, but a tendon that isn't loaded becomes less capable, so pain tends to return as soon as normal activity resumes. Reduced or modified loading is a very different thing from no loading at all. The exception is a suspected tear or an acutely injured tendon, which needs assessment before anything else.
Is morning stiffness in the Achilles normal?
It's one of the most characteristic features of Achilles tendinopathy: stiff and sore for the first steps of the day, easing as you warm up. It also makes a useful progress marker. Morning stiffness that's gradually shortening or lessening over the course of weeks is a reasonable sign things are heading the right direction.
Can I keep running while I rehab it?
Often yes, but usually in a modified form rather than business as usual. It depends on how irritable the tendon currently is and how it responds over the following day. This is exactly the kind of judgment call worth making with a clinician who can assess you, rather than with a general article.
Want the structure without piecing it together yourself?
There's one self-guided program I recommend that covers everything in this article, in the right order. Here's my full review, including who shouldn't buy it.
Read the DGR program review →This is educational content, not medical advice. I'm a licensed physical therapist, but nothing on this site is provided in that capacity, and reading it doesn't make me your physical therapist. I'm sharing education about conditions and rehab principles, not treating you. Always get clearance from your physician, physical therapist, or another qualified medical professional before starting any new exercise or rehab program. Sudden severe pain, a snapping sensation, or inability to push off your foot needs urgent assessment, not a program. Read the full disclaimer.