Achilles Tendinopathy and Tibialis Posterior Tendinopathy in Runners: My 5-Month Recovery and What Actually Helped
- Chris Herbs
- a few seconds ago
- 6 min read
Achilles tendinopathy and tibialis posterior tendinopathy are two of the most common overuse injuries I see in runners. Over the past five months, I dealt with both myself, and the experience changed how I think about rehab, training load, and recovery timelines.
If I’m being honest, I’ve dealt with on-and-off right Achilles pain for a few years now, and like many runners, I never fully addressed it.
I’m my own worst patient.
After a mostly successful training block leading into the 2025 Maine Coast Marathon, symptoms started to worsen. Looking back, I suspect the cambered roads on the course, something I wasn’t used to, played a role. After Maine Coast, I was able to navigate a mostly successful summer of training before truly injuring myself during the 2025 Charles River Marathon Invitational, where I pushed through pouring rain to run a 2:53:46 in an attempt at a last minute Boston Qualifying time.
My effort that day may not have been fast enough to make the additional Boston Marathon cut-off, but it was enough to push my achilles tendinopathy and tibialis posterior tendinopathy over the edge.
A quick primer: Achilles tendinopathy and tibialis posterior tendinopathy are two of the most common injuries I see in runners. The Achilles tendon helps store and release energy with every step, and the tibialis posterior plays a critical role in both supporting the arch of the foot, and managing, storing, and transmitting load through the arch and ankle during stance and push-off. When the overall workload on these tendons outpace the body’s ability to recover and adapt, these tissues can become painful and sensitive.
Around mile 20, I knew something wasn’t right. The mild tightness in my leg that I had become accustomed to had turned into a sharp, deep burning. I remember thinking, “Give it whatever you’ve got now, because you’re probably going to need a couple weeks off after this.”
That “couple weeks” turned into nearly two full months away from running.
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There were a lot of variables playing into my injury.
At the time I had spent most of the last year running, for me, pretty hard:
Two full marathon cycles with some shorter races in between
50–65 miles per week
Weekly tempo runs
Long runs with tempo segments
Minimal down time between training cycles
And outside of running, life stress was high. Over the last few months, I had:
Quit my job to launch Miles Ahead
Moved out of Somerville after 7 years
Moved in with my girlfriend on the other side of the city in South Boston
All good things overall, but emotionally heavy and stressful. While the influence of physical stress on the development of injuries is obvious, it’s important to remember that life stress has a significant impact as well.
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When It Went from “Sore” to "Serious"
After the marathon, symptoms escalated dramatically. I was experiencing:
Severe calf, Achilles, and ankle stiffness
Pain wrapping behind the medial malleolus into the arch of my foot as well as at the insertion of my Achilles
Numbness and tingling in the heel (likely tibial nerve irritation)
Significant swelling
sensitivity touch at the heel
I was limping heavily with walking and could barely get up and down stairs for the first few days because of the pain in my lower leg.
This wasn’t just a sore tendon anymore.
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The Emotional Side No One Talks About
My first reaction wasn’t fear. It was annoyance.
I was able to quickly self diagnose myself with tibialis posterior tendinopathy, on top of an acute aggravation of my chronic Achilles tendinopathy.
But the deeper stress came from something else.
I had just launched Miles Ahead.
Running wasn’t just exercise and a way to unwind. It was my way of staying present in the community and connecting with runners. Continuing to be an active member of the Boston running community is how I grow my business. But now I could barely walk, let alone run.
I also felt self-conscious. As a running specialist physical therapist and run coach, I always feel a bit of pressure to run fairly well relative to my goals, and to stay generally healthy. When I can’t do those things, I didn’t just fear losing fitness and identity. As ridiculous as it may sound, part of me also worried about losing credibility.
On top of all of that, things took much longer than to improve than I expected. Even though I know Achilles tendinopathy and tibialis posterior tendinopathy can take months to improve, part of me hoped I would be different. And as weeks passed, doubt crept in:
“What if this is worse than I think?”
Fortunately, around the six-week mark, things finally started to turn.
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The Rehab Process (and What Actually Worked)
While I couldn’t run, I did not stop moving.
One of the biggest misconceptions about tendon injuries is that they require prolonged rest. In reality, appropriately dosed loading is one of the most effective ways to improve tendon capacity and reduce pain over time. The key is finding the right starting point: enough stimulus to promote healing and adaptation without overwhelming an already sensitive tissue.
Personally, I focused on daily walking, cross training on the spin bike and elliptical, resistance training, and rehab exercises for my lower leg.
I’ll dive into the specifics of treating an Achilles tendinopathy and tibialis posterior tendinopathy in my next blog post. But I will say, I often felt much better after loading the injured tissues compared to resting completely. Conceptually I knew to expect that, but experiencing it myself was huge for confidence.
Major milestones I hit along the way:
Comfortable single-leg weighted heel raises (~4 weeks)
First easy run ~7 weeks
First fartlek (11 weeks)
First 10-mile run (3 months)
First pain-free double-digit run (4 months)
Confident single-leg hopping ( ~4.5 months)
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The Mistakes I Made (Yes, Even as a PT)
I underloaded for too long early on.
Even knowing the science, I was shocked by the symptom intensity I experienced. I became overly cautious and let fear slow my progression.
I also did not start cross training as heavily as I could have, partly because I simply didn’t expect to be unable to run for so long. Maintaining more of my fitness was possible.
Mentally, I stressed more than necessary about my running injury. If I had to do it again, I would lean more on coping tools like therapy and mindfulness techniques, and steer even harder into other hobbies and social activities. Injuries aren’t just physical.
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Where I Am Now
Recovery from Achilles tendinopathy and tibialis posterior tendinopathy, or any running injury for that matter, is rarely linear. Many runners experience fluctuating symptoms throughout the rehab process. Monitoring trends in symptoms over weeks rather than reacting to individual “bad days” was extremely helpful for me.
Today, I feel ~90% better. I am back up 30–40+ mile weeks. I have minimal discomfort early in runs, which often warms up and resolves completely, and I’m able to consistently progress the length and intensity of runs without symptoms worsening. Looking ahead, I feel optimistic that I’ll be ready to take a real swing at the Chicago Marathon in October.
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What This Injury Taught Me
Small aches and pains can become big injuries.
I downplayed the significance of what I was dealing with over the last two years at my achilles. If I truly addressed it sooner, all of this could have been avoided, or at least been less severe.
2. Recovery often takes longer than you want
Even knowing the healing timeline, living through it was a lot for me. Managing a running injury requires patience.
3. Discomfort is part of the process
Early rehab can feel worse before it feels better, and that doesn’t necessarily mean you’re doing harm. Again, this is something that I would tell my own patients, but struggled with myself.
Advice to Runners Dealing with Achilles or Tib Post Issues:
Address symptoms early. Don’t wait for them to escalate
Expect recovery to take several weeks to months, not days to weeks. Especially if you have been dealing with pain for a long time.
Stay fully consistent with your loading routine during rehab.
Maintain aerobic fitness during downtime
Avoid overcomplicating rehab. Simple works
Final Thoughts
Getting injured didn’t make me a worse running specialist physical therapist or coach. If anything, it made me better.
It emphasized me what runners actually experience when dealing with injury:
Fear
Frustration
Identity challenges
The long road back
Recovery isn’t about perfection.
It’s about patient, progressive work, and trusting the process.
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If You’re Dealing with Something Similar…
If you’re struggling with Achilles or tibialis posterior pain, or persistent running injuries, you’re not alone.
Miles Ahead Physical Therapy and Performance helps runners bridge the gap between rehab and training so they can return stronger, more durable, and more confident. Set up a discovery call today to see how Miles Ahead can help you!