Why Tendon Pain Lingers — and What It Really Takes to Heal
You’ve backed off your training, iced the sore area, maybe even tried a round of PT. The tendon pain eased a bit—only to return as soon as you ramped things up again.
Whether it's your Achilles tightening after a run, your shoulder aching after overhead presses, or your knee flaring up after long walks—this cycle of pain and rest feels endless. But here’s the truth:
Tendons don’t just need time. They need load — the right kind, in the right amount, at the right time.
At Zero Point One Physical Therapy, we see this scenario every day: active adults trying to stay strong, mobile, and injury-free — but stuck in patterns of recurring tendon pain. The issue isn’t a lack of effort or commitment. It’s a mismatch between what the tendon needs to heal and what most rehab strategies actually provide.
Tendons Aren’t Broken — They’re Underprepared
Tendons are the connective tissue that link muscle to bone. They’re built to store and release force — think running, lifting, jumping, walking up stairs. But unlike muscles, they adapt more slowly, and they don’t love unpredictability.
What we now understand through recent research is that tendinopathy — the umbrella term for tendon irritation and pain — isn’t just about inflammation. It’s a complex process involving tissue breakdown, misaligned collagen, and low-grade chronic stress that builds up over time.
According to a 2023 review published in International Journal of Molecular Sciences (PMID: 37894875), tendon healing occurs in three overlapping phases:
Inflammation – where the body responds to microtrauma
Proliferation – where tendon cells begin laying down new collagen
Remodeling – where those fibers realign, strengthen, and regain tensile capacity
The problem? In many cases — especially after 30 or 40 — this process stalls, either from underloading, overloading, or a mix of both. The tendon doesn’t regain its capacity, and pain becomes persistent.
Why It’s Not Just About Age — But Aging Still Matters
There’s a reason that tendon injuries often show up in people who are either highly active or slowly drifting away from consistent movement.
As we age, even slightly, tendons start to change:
Reduced blood flow and oxygenation
Slower cellular turnover
More stiffness, less elasticity
Higher levels of low-grade inflammation
One of the key drivers is the decline in TSPCs (tendon stem/progenitor cells), which play a huge role in the tendon’s ability to rebuild. These cells become less responsive with age, and the collagen they help produce becomes more disorganized — like frayed rope rather than tightly wound fibers.
And if you’ve ever felt like “it just takes longer to bounce back” now — you’re not imagining it.
The pain might not be loud at first. A little stiffness in the morning, a dull ache after workouts, or that annoying tightness that shows up after sitting too long. But left unchecked, it becomes more limiting — affecting how you move, train, and live.
Rest Isn’t Rehab — and Pain-Free Isn’t Fully Healed
When tendon pain first starts, it’s natural to back off. In some cases, that’s exactly what’s needed. But if rest is the only strategy, here’s what often happens:
Pain goes down, but the tendon stays weak
You return to activity, but the tissue isn’t ready
Symptoms flare again, often worse than before
This cycle frustrates people who are trying to stay fit, stay consistent, and stay active. They start to lose confidence in their body, unsure of what’s safe to do and what will make things worse.
The Most Common Pattern We See — and Why It Doesn’t Work
Here’s how it usually goes:
You feel a flare-up — knee, Achilles, shoulder. It’s stiff, sore, maybe swollen.
You stop training and take some rest. Maybe you stretch or ice.
The pain subsides, so you go back to your usual workouts.
A few sessions later — the pain returns, sometimes worse than before.
This cycle is one of the most common things we see in our clinic. It’s frustrating, disheartening, and unfortunately, entirely predictable.
What’s really happening?
The tendon is being underloaded during recovery — not challenged enough to rebuild its capacity — and then overloaded too quickly once activity resumes. This mismatch leads to a vulnerable, poorly remodeled tendon that simply can’t keep up.
Pain relief doesn’t mean the tendon is strong enough for real life or sport. And skipping the progressive strength work in between is exactly what keeps people stuck.
Whether it’s patellar tendon pain during squats, a rotator cuff flare-up from push presses, or Achilles tightness on your runs, the pattern is the same: rest without progressive reloading leads to incomplete healing.
The solution isn’t just more rest. It’s smarter programming, thoughtful progression, and knowing when and how to load the tendon.
So What Actually Works?
The research is clear: progressive loading is the only way tendons regain their ability to tolerate stress.
Here’s how we approach it at Zero Point One:
Step 1: Understand What the Tendon Needs
We start with a detailed 1-on-1 evaluation. We look beyond the pain to examine how you move, where your tendon sits in the healing timeline, and what’s breaking down under load.
It’s not about stopping activity altogether — it’s about identifying what kind of loading the tendon can currently tolerate.
Step 2: Rebuild Tissue with Targeted Strength Work
We use a combination of:
Isometrics to calm pain and stimulate early tissue remodeling
Eccentrics to realign collagen and build control
Heavy, slow resistance to rebuild tendon stiffness and strength
Movement patterning and functional drills to restore dynamic control
Everything is progressed based on your response — not a cookie-cutter protocol. We listen to pain signals, but we also use objective testing and training metrics to guide each phase.
Step 3: Raise Capacity for Real-Life Demands
Once the tendon is tolerating foundational strength work, we start rebuilding its true job: storing and releasing force. That means:
Reintroducing running, lifting, or impact-based drills
Restoring rate of force development (how quickly you can produce strength)
Coaching return-to-sport or fitness programming with precision
This phase often gets skipped. But this is where real transformation happens — not just “getting back to normal,” but building something better than before.
What About Supplements, Injections, or Surgery?
They all have a place — but none of them replace load. You can reduce pain or stimulate healing with certain interventions, but without reloading the tendon appropriately, the structure doesn’t rebuild.
Growth factors like IGF-1, PDGF, and TGFβ play important roles in tendon healing, and there's exciting research on things like PRP injections or collagen support, but they are most effective when combined with mechanical loading and progressive rehab.
Load is the language that tendons speak. If you want a healthier tendon, it has to be trained, not just treated.
Final Takeaways: You Can’t Skip the Work — But You Can Do It Smarter
Tendon injuries are not just inflammatory — they’re mechanical and structural
Healing slows with age, but it’s absolutely still possible with the right strategy
Rest, ice, and passive care are not enough
A personalized, progressive loading plan is essential
You don’t have to live with pain — but you do need a plan
Ready to Rebuild?
If you’ve been told to “just stretch” or “give it time,” and you’re still not where you want to be — it’s time for a new approach. We help people rebuild tendon health so they can move better, train harder, and live without second-guessing their body.
Works Cited
Kwan CC, et al. “Aging and Tendon Healing.” Int J Mol Sci. 2023. PMID: 37894875
Järvinen TA, et al. "Muscle injuries: biology and treatment." Am J Sports Med. 2005. PMID: 16934204
Thorpe CT, et al. "Extracellular matrix assembly and cell signalling in tendon." J Orthop Res. 2015. PMID: 23331954
Yin H, et al. "Aging aggravates tendon injury-induced oxidative stress and fibrosis." Oxid Med Cell Longev. 2020. PMID: 32010194
Park Y, et al. "Advanced Glycation End-Products and Tendon Healing." Int J Mol Sci. 2023. PMID: 37894875