What is Tendinopathy and Why Rest Isn't the Answer

If you've ever had stubborn pain at the back of your heel, the base of your kneecap, or the outside of your hip that just won't go away, there's a reasonable chance you've been dealing with tendinopathy. If you've been managing it with rest, you may be making it harder to recover, not easier.

Tendinopathy is one of the most commonly misunderstood and mismanaged injuries in active people. Here's what it actually is, why it behaves the way it does, and what the evidence supports for treatment.

What is tendinopathy?

Tendinopathy is a broad term that describes tendon pain and dysfunction. It covers a spectrum of tendon pathology that has historically been poorly understood, partly because for decades clinicians assumed tendon pain was driven primarily by inflammation, the same way a muscle strain or a bruise is.

Histological research, meaning studies that examine actual tendon tissue, has shifted this picture significantly. The tissue of a symptomatic tendon tends to show degenerative changes including disorganised collagen fibres, changes in cell structure, and altered tendon composition, often with absent or minimal classical inflammatory cell infiltration. This is why the older term "tendinitis" (implying active inflammation) has largely been replaced in clinical practice with "tendinopathy," a term that more accurately reflects the complexity of the condition.

One of the most widely used frameworks for understanding tendinopathy is the continuum model, proposed by Cook and Purdam in 2009 and still clinically relevant today. It describes tendon pathology as a three-stage continuum: reactive tendinopathy, tendon dysrepair, and degenerative tendinopathy. Each stage has different characteristics and responds differently to treatment. The key clinical insight from this model is that tendons are not static. They can move along this continuum in both directions, and the most important variable in determining which direction they move is load.

Why rest makes it worse

This is the part that surprises most people. For most musculoskeletal injuries, rest makes intuitive sense, but tendons are different. Tendons adapt and maintain their health through mechanical load. When you remove load entirely, tendon tissue does not recover. It deconditions. The tendon loses its capacity to tolerate the demands that will eventually be placed back on it when you return to activity, which is precisely why so many people find that tendon pain returns the moment they try to get back to training after a period of rest.

Complete rest might temporarily reduce symptoms, because you have simply dropped below the load threshold that provokes pain. However, it does not address the underlying issue, which is a tendon that lacks the capacity to handle the load being asked of it.

What the evidence supports: progressive loading

The most well-supported approach to tendinopathy rehabilitation is progressive tendon loading. The principle is straightforward: you expose the tendon to carefully managed load, progressively increasing that load over time, to drive adaptation and rebuild tendon capacity.

One well-studied approach is heavy slow resistance training, which involves performing exercises through a full range of motion at a slow tempo with significant load. A randomised controlled trial published in the American Journal of Sports Medicine compared heavy slow resistance training to traditional eccentric training in patients with Achilles tendinopathy over 12 weeks. Both groups showed statistically significant improvements in function and pain, with heavy slow resistance training associated with greater patient satisfaction at the 12-week mark. These improvements were maintained at 52-week follow-up.

The specifics of the loading program will vary depending on which tendon is affected, the stage of pathology, your training background, and your goals. But the underlying principle holds across presentations: managed, progressive load is the treatment, not the absence of it.

What about pain during exercise?

This is one of the most common questions in tendinopathy rehabilitation, and the answer requires some nuance. A small amount of pain during loading is generally acceptable, provided it settles within 24 hours and does not progressively worsen over the course of the program. Using pain as a guide, rather than trying to avoid it completely, is a more clinically useful approach and is consistent with current evidence-based practice guidelines.

This is also where working with a physiotherapist who understands load management and training matters. The goal is not to push through pain indiscriminately. It's to find the right dose of load that drives adaptation without provoking a flare.

The common mistakes that keep tendons stuck

Beyond rest, a few other patterns tend to keep tendinopathy from resolving. Doing too much too soon when symptoms improve, failing to address strength deficits in the muscles that load the tendon, returning to sport or training before the tendon has sufficient capacity, and stretching the tendon aggressively in the belief that it will help, which in some presentations can actually compress the tendon and worsen symptoms.

Tendinopathy responds to a systematic approach, not a passive one. The people who recover well are the ones who commit to a progressive program, monitor their response honestly, and make adjustments based on how the tendon is behaving over time.

If you've been managing tendon pain on your own without progress, an assessment can help clarify what stage you're at, what's driving the problem, and what a structured loading program should look like for your specific situation. Book an online assessment with Live Bright Physiotherapy.

References‍ ‍

1. 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. 2009;43(6):409-416. https://pubmed.ncbi.nlm.nih.gov/18812414/‍ ‍

2. Beyer R, Kongsgaard M, Hougs Kjaer B, et al. Heavy Slow Resistance Versus Eccentric Training as Treatment for Achilles Tendinopathy: A Randomized Controlled Trial. American Journal of Sports Medicine. 2015;43(7):1704-1711. https://pubmed.ncbi.nlm.nih.gov/26018970/‍ ‍

3. StatPearls. Tendinosis. National Library of Medicine. Updated 2025. https://www.ncbi.nlm.nih.gov/books/NBK448174/‍ ‍