By Ian Markow, FRCms, EXOS Performance Specialist, StrongFirst SFG1, NASM-CPT. Fifteen years coaching movement, strength, and rehab in Boca Raton, FL.
You feel it in the back of your lower leg. A stiff, tender ache in the cord above your heel, or right where the tendon meets the heel bone. It is worst with the first few steps in the morning. It warms up, you forget about it, then it shows up again the next day.
You rested it. You stretched it. You iced it. Maybe you bought new shoes. It settled for a bit. Then you ran, or jumped, or just walked a lot, and it came right back.
Here is the part nobody tells you. That pattern is not bad luck. It is the tendon telling you something specific. And most people read the message wrong.
Let me reframe what is actually happening in the back of your leg. Once you see it, the reason your last fix failed becomes obvious.
What Achilles tendinopathy actually is
Achilles tendinopathy is a load problem in the tendon that connects your calf to your heel. It is not simple inflammation, and it is not something you can wait out.
The old name was tendonitis, which implied inflammation. Then tendinosis, which implied wear and tear. Both are too narrow. The modern term is tendinopathy because tendon pain usually involves three things at once: the tendon tissue itself, the nerves, and your nervous system.
There are two places it shows up, and the difference matters. Midportion Achilles tendinopathy sits in the cord itself, a couple of inches above the heel. Insertional Achilles tendinopathy sits lower, right where the tendon attaches to the heel bone. They look similar from the outside. They do not respond to the same things, and one of the most common fixes makes the insertional kind worse.
That distinction matters. It is the reason the standard advice fails. You cannot ice your way out of a problem that is only partly inflammation, and you cannot stretch your way out of a problem that stretching can aggravate.
Why Achilles tendinopathy happens
Achilles tendinopathy happens when the tendon gets more stress and strain than it is set up to handle, faster than it can recover. It is a supply and demand problem, not a random injury.
It is a supply and demand problem. Not a random injury.
The Achilles is the biggest spring in your body. Every step you run, it stretches as your ankle bends forward, stores that energy, and snaps you off the ground. Do that within the tendon’s capacity and it gets stronger. Exceed that capacity before it recovers and it starts to break down.
The breakdown almost always traces back to one of a few training errors:
- Too much, too soon. The runner who jumps from twenty miles a week to forty. The person who starts a new job on their feet all day.
- Peaks and valleys. Train hard for a month, get busy, take three weeks off, then jump right back in at the old volume.
- A new kind of stress. Switching to a flatter, more minimal shoe. Adding hills or speed work. Moving from the treadmill to the road. The tendon meets a load it never adapted to.
None of these guarantees Achilles pain. They stack the odds. This is why two runners on the same training plan can have completely different tendons.
That is also why generic advice cannot fix it. Your tendon broke down along your specific path. It rebuilds along a specific path too.
Specific breakdown. Specific rebuild.
Why rest makes it feel better, then worse
Rest calms the pain because it removes the load. It does not rebuild the tendon, so the pain comes back the moment load returns. Rest treats the symptom and starves the fix.
Here is the honest, complicated part most people never hear.
A short flare of tendon pain follows a predictable arc. The tendon swells, pressure rises inside it, the local nerves fire, and over a few days it settles on its own. That is the version rest seems to solve.
But when that normal resolution fails, the problem changes character. New sensory nerves grow deeper into the tendon, into places they do not belong. They start firing at loads that should not hurt. The pain stops being a pure tissue problem and becomes a tissue and nervous system problem.
Now you are in the version that lingers for months. And the more you rest a tendon in this state, the weaker and less tolerant it gets. The calf shrinks. The tendon loses capacity. You are not healing. You are detraining the exact tissue that needs to get stronger.
That is the trap. The thing that gives you short-term relief is quietly making the long-term problem harder to solve.
Short-term relief is quietly making the long-term problem harder to solve.
Why the common fixes usually fail
Stretching, ice, foam rolling, new shoes, and cortisone shots target the wrong layer of the problem. They chase the pain. They do not build the tendon’s capacity to handle load, which is the actual deficit.
Stretching deserves its own warning. If your pain is insertional, right at the heel bone, deep calf stretching drives the tendon into the bone and compresses the exact spot that hurts. Flat, minimal shoes do the same thing. That is why so many people with heel-level Achilles pain get worse the harder they stretch. Early on, that kind of Achilles often wants less stretch and a small heel lift, not more.
Ice and rolling feel good and change nothing structural. Cortisone can quiet pain for a few weeks, but injecting it around the Achilles carries a real risk of weakening the tendon and is generally avoided for that reason.
There is also the part above the tendon that gets ignored completely. When your Achilles hurts, your calf loses size and strength, and your foot and hip change how you push off and land to protect it. Fix the tendon and ignore the weak calf, and you walk right back into the same breakdown.
This is where most self-directed rehab and most generic programs quit. They treat the sore spot. They never rebuild the system that let it get sore.
Treating the sore spot is not the same as rebuilding the system.
Two things you can try right now for relief
A heavy isometric calf hold can quiet Achilles pain, sometimes within minutes. This is one of the few things that actually calms an angry tendon in the moment instead of just masking it.
Try this. Rise up onto the ball of one foot, or push into a calf raise on a machine or a wall, and hold near the top where the calf is working hard but the tendon does not sharpen. Then hold. You are looking for a strong, steady contraction in the calf. Done right, the Achilles pain often drops while you hold and stays lower for a while after. If your pain is at the heel, keep the foot flatter and do not let the heel drop into a deep stretch.
The version in the photo is a bent-knee option. Bending the knee and holding the ankle in dorsiflexion shifts more of the work onto the soleus, the deeper calf muscle under the gastrocnemius. It is a useful variation, especially for runners. One caveat. That dorsiflexed position drives the tendon into the heel bone, so if your pain is insertional it may not feel as good as the straighter, flatter-footed calf raise hold above. Midportion pain usually tolerates it fine.
You have two ways to load this. Against a wall it takes no equipment and travels anywhere. In the gym, a seated calf raise trains the same bent-knee, soleus-focused position and lets you add weight and progress it over time. One is free and portable. One is loadable and easy to scale.
Knee angle changes which muscle you load. A straight knee, like this Smith machine hold, works the gastrocnemius, the big calf muscle you can see. Bend the knee and the gastrocnemius goes slack, which hands the work to the soleus underneath. Train both and you cover the whole calf that feeds the tendon.
The Smith machine is the one I reach for first. You can load it and add weight week to week, which is how you climb out of the early phase instead of stalling at bodyweight. No Smith machine is fine. Do the same hold standing on the ball of one foot, hold something so you are not fighting for balance, and go bodyweight or hold a dumbbell in one hand.
Where your pain sits changes the range, not the position. Knee angle picks the muscle. How far you let the heel drop picks how it feels. Insertional pain, right at the heel, wants a shorter range and no deep stretch, because that compresses the tendon against the bone. Midportion pain, higher in the cord, usually tolerates more range.
The second piece, if the pain is insertional, is a small heel lift in your shoe for a while. It takes the tendon off the bone and out of the position that compresses it, so the area can settle.
Here is the honest catch. How heavy, what range, how long you hold, how many times a day, and when you progress are the entire difference between calming the tendon and flaring it. Those numbers are not one-size-fits-all. They change based on where your pain is, your sport, and how the tendon answers the next morning. Guess them and you can set yourself back weeks.
That dialing-in is exactly what a coach does. The hold gives you relief. The plan gets you better.
What actually changes a tendon
A tendon changes through the right load, applied in the right dose, progressed in the right order, and guided by how it responds the next day. That is the whole game. The details are what separate recovery from another six months of frustration.
Tendons are not static tissue. A painful tendon has actually re-entered a rebuilding phase. It is laying down new collagen and trying to remodel. Load is the signal that tells it how to rebuild. Too little and nothing changes. Too much and you push it further into breakdown. The window between those two is real, it is measurable, and it is different for every person and every stage of recovery.
Getting it right means starting at the highest level the tendon can handle, not the gentlest. It means reading next-morning stiffness as data. It means building the calf back through weight, then range, then speed, in the correct order, and returning to running last, once the tendon can take stress again.
Start at the highest load the tendon can handle. Not the gentlest.
That is a plan built around your Achilles. Not a list of exercises off the internet. Not the same protocol handed to everyone.
That is what our coaching is built to do. We map the plan to the person, not the other way around.
Ready to fix the actual problem?
If you are tired of resting, flaring, and starting over, let’s map out what your Achilles actually needs.
Book a free strategy call. We will talk about where you are now, what has been holding you back, and how to build a plan around your tendon and your goals. No pressure, no guesswork.
About the author
Ian Markow is the founder of Markow Training Systems in Boca Raton, FL. He holds credentials including FRCms, Kinstretch, Stick Mobility, EXOS Performance Specialist, StrongFirst SFG1, MoveMed Level 1, NASM-CPT, and NCCPT. He has spent fifteen years coaching runners, lifters, and everyday clients through pain, rehab, and performance, in person and online. His approach reframes the problem and assesses the person before prescribing anything.
Ready to stop guessing with your Achilles? Book a strategy call with the Markow Training Systems team. We coach clients in person in Boca Raton and online worldwide. Book a strategy call.
Common questions about Achilles tendinopathy
What is the difference between Achilles tendinopathy and Achilles tendonitis?
They describe the same area of pain, but tendinopathy is the accurate term. Tendonitis implies pure inflammation. Most lasting Achilles pain involves the tendon tissue, the nerves, and the nervous system, not just inflammation, which is why anti-inflammatory approaches alone often fail.
Where does Achilles tendinopathy hurt?
Two spots. Midportion pain sits in the cord about two to three inches above the heel. Insertional pain sits lower, right where the tendon attaches to the heel bone. The location changes what helps, especially around stretching and shoes.
Will Achilles tendinopathy heal on its own with rest?
Usually no. Rest reduces pain by removing load, but it does not rebuild the tendon’s capacity, so the pain returns when activity resumes. Long-standing cases often get worse with pure rest because the calf and tendon lose strength and tolerance.
How common is Achilles tendinopathy?
Very common, especially in runners. Lifetime incidence in runners is estimated as high as 50%, while about 6% of the general population is affected. It also shows up in lifters, field-sport athletes, and people who spend all day on their feet.
What exercise helps Achilles tendon pain right now?
A heavy isometric calf hold, such as holding the top of a calf raise, can reduce Achilles pain acutely, often within minutes. It calms the tendon rather than masking it. The relief is real, but the dose that keeps it improving without flaring is individual and is what a coach dials in.
Should I stretch my Achilles?
Be careful, especially if the pain is at the heel. Deep calf stretching compresses an insertional Achilles against the heel bone and can make it worse. Midportion pain tolerates gentle stretch better. When in doubt, load the tendon rather than stretch it.
Why is my Achilles worse in the morning?
Morning stiffness that eases as you warm up is one of the most reliable signs of Achilles tendinopathy. How stiff it is the morning after training is also the best readout of whether the previous day’s load was too much.
How long does Achilles tendinopathy take to recover?
It varies widely based on how long it has been present, whether it is midportion or insertional, and how well loading is managed. A well-built, individualized plan is the biggest factor in how fast and how completely it resolves.
Sources and further reading
- de Vos RJ, van der Vlist AC, et al. Achilles tendinopathy. Nature Reviews Disease Primers. 2025.
- Silbernagel KG, et al. Continued sports activity and heavy-load resistance training in Achilles tendinopathy.
- Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. British Journal of Sports Medicine.
- Tuura J. Tendon and tendon rehab principles, Jacked Athlete. Tendon anatomy, breakdown, pain science, compression, and the Silbernagel loading approach referenced in this article.
