Tendon Rehab: Stop Making This Mistake. New Evidence For Faster Recovery
Des Kelly, Physiotherapist - Move Sports Physio Geelong
Why ‘rest’ is making it worse
Tendon pain is one of the most common reasons active people get sidelined (even for non-athletes) most often at the Achilles, patellar, gluteal, lateral elbow and rotator cuff tendons. Many are told they have "tendinitis", advised to rest and take anti-inflammatories, then find the pain returns once they get active again.
Two decades of research can now explain why tendons get better with the right kind of load, and good nutrition. Not rest.
Tendinitis vs tendinopathy: what's the difference?
Tendinopathy is now the preferred umbrella term for painful, load-related tendon problems; tendinitis (or tendonitis) describes a narrower, inflammation-led picture that is less common than the name suggests.
Tendinitis
The "-itis" suffix means inflammation. Before the 1990s, almost every painful tendon was labelled tendinitis because inflammation was assumed to drive the problem (tendinopathy review, Disease-a-Month 2021). Classic tendinitis is best reserved for an acute tendon injury, often after unaccustomed activity or a single bout of heavy exertion, with a genuine inflammatory response in or around the tendon (AAPM&R).
In 2019 an international expert consensus (ICON) agreed that tendinopathy is the preferred term for persistent tendon pain and loss of function related to mechanical loading, and that imaging is not always needed to diagnose it (ICON 2019 clinical terminology, BJSM). Inside the tendon you typically see disorganised collagen, new blood vessels and nerve ingrowth, disrupted matrix turnover, and cell death (Millar et al., Nature Reviews Disease Primers 2021).
The twist: inflammation is not absent
Tendinopathy was long described as purely "degenerative", but molecular research shows immune cells and inflammatory mediators are present across the spectrum, especially early (Millar et al., Nature Reviews Rheumatology). This is low-grade molecular inflammation, not the hot, swollen kind, which is why anti-inflammatories alone rarely fix a chronic tendon.
The continuum model
Cook and Purdam's widely used model describes tendon pathology as a continuum rather than fixed categories: a reactive stage after a load spike, a dysrepair stage of failed healing, and a degenerative stage. Early stages can reverse with the right load, and a tendon can flare into a "reactive-on-degenerative" state (Cook & Purdam 2009, BJSM). In practice, the "tendinitis" presentation most people experience maps onto the reactive stage.
Acute / reactive ("tendinitis") | Persistent tendinopathy | |
Typical onset | Days after a sudden load spike (new sport, big session, hills) | Weeks to months, often recurrent |
What's happening | Short-term cell and matrix response; true inflammation possible | Disorganised collagen, new vessels and nerves, low-grade molecular inflammation |
Swelling | Diffuse swelling or thickening common | Localised thickening; less acute swelling |
Pain pattern | Irritable; sore with most loading | Warms up then aggravates later or next morning |
Main rehab goal | Settle symptoms, reduce provocative load, keep moving | Rebuild capacity with progressive loading |
This is a spectrum, not a switch. Other conditions (tears, bursitis, nerve irritation, inflammatory arthritis) can mimic tendon pain, so get the diagnosis confirmed.
Rehabbing an acute, reactive "tendinitis"
The goal early on is to calm the tendon down by reducing the load that irritated it, without resting it completely. Complete rest lets the tendon and muscle lose capacity, which sets you up for a flare when you return.
1. Modify load, don't abandon it
In a reactive tendon, adjusting the intensity, duration, frequency and type of load is the key intervention, and removing the cause (usually a spike in unaccustomed load) comes first (Load management in tendinopathy, Apunts). In practice that means cutting back the aggravating activity (fewer hills, less jumping, shorter runs), not stopping all movement. Tendons also dislike compression, so positions that squash the tendon against bone (deep ankle dorsiflexion for insertional Achilles, crossing legs for gluteal tendons) are often reduced early.
2. Isometrics: useful, but not magic
Isometric holds (e.g. a 30–45 second wall-sit or calf-raise hold) became popular after a small 2015 study suggested immediate pain relief. A 2020 meta-analysis found them no better than moving (isotonic) exercise for pain, with highly variable responses (Clifford et al., BMJ Open Sport & Exercise Medicine 2020), and an Achilles trial found no immediate relief at all (van der Vlist et al. 2020). Use them as a well-tolerated starting point, not the treatment.
3. Anti-inflammatories: short-term pain relief at best
In human Achilles tendinopathy, ibuprofen gave moderate pain relief but triggered no repair response in the tendon (Heinemeier et al., Journal of Applied Physiology). If you use a short course, check with your doctor or pharmacist first, as NSAIDs carry gut, kidney and cardiovascular risks.
4. Ice
Ice can ease pain in the short term and is low risk, but it does not heal the tendon. Treat it as symptom relief.
5. Use pain as a guide. A practical rule from Achilles research is that some pain during activity is acceptable if it stays at or below about 5/10, settles quickly, and is no worse the next morning (Silbernagel et al. 2007, AJSM). Morning stiffness or pain that lingers more than 24 hours signals that you did too much.
A reactive tendon usually settles within days to a few weeks with sensible load changes. Once it does, progress to the strengthening approach in the next section. If it doesn't settle, see a physiotherapist or sports doctor.
Rehabbing persistent 'tendinopathy'
Progressive, heavy-as-tolerated tendon loading is the only treatment with strong (Grade A) evidence, and it should be first-line care for almost everyone with a persistent tendon problem.
What the guidelines say. The 2024 revision of the US physical therapy guideline for midportion Achilles tendinopathy gives tendon-loading exercise its only Grade A recommendation, pairs it with education (Grade B), and advises against complete rest (Physical Therapy First summary). It recommends loading at least three times a week at the highest intensity you can tolerate, progressing from isometric and isotonic work toward plyometrics. Importantly, it expanded the old "eccentrics only" advice to include all contraction types (Journal of Physiotherapy appraisal; full guideline, JOSPT).
Eccentrics vs heavy slow resistance (HSR). Eccentric-only programs (such as the Alfredson heel-drop) dominated for two decades. HSR uses slow, heavy lifts through both phases, typically three sessions a week for 12 weeks, progressing from about 15-rep-max to 6-rep-max loads. A May 2026 network meta-analysis of patellar tendinopathy trials found no program clearly beat HSR, with several progressive loading approaches performing similarly and only pure concentric work clearly lagging (Liu et al., BMC Sports Sci Med Rehabil 2026). Progressive loading matters more than the specific program.
A typical progression
Most evidence-based programs follow a similar arc, moving on when pain is stable and the current stage feels easy:
Isometrics — holds to calm pain and maintain strength (see previous section).
Slow, heavy strength work — HSR-style lifts, e.g. seated and standing calf raises for the Achilles, leg press or Spanish squats for the patellar tendon.
Faster, energy-storage loading — hopping, skipping, bounding, jumping; the tendon's spring function must be retrained before sport.
Return to sport or running — graded exposure, with the strength program continued.
How long does it take?
At least 12 weeks, often 3–6 months or more for long-standing cases, because tendon collagen turns over far more slowly than muscle. Keep strength training going after symptoms settle to reduce recurrence.
Education matters too
Knowing that pain doesn't equal damage and that recovery takes months improves adherence, the biggest barrier to success.
Nutrition for tendon health
Nutrition supports tendon rehab but cannot replace loading: eat enough overall, get enough protein, and consider collagen plus vitamin C taken before your loading sessions.
Stop cutting calories
A 2026 review concluded that adequate energy and protein intake come before any targeted supplement, because under-eating diverts amino acids to fuel rather than repair (Healthcare 2026). Athletes who cut food while injured and training less should take note.
Collagen + vitamin C: the most promising supplement
Tendons are mostly type I collagen, and vitamin C is needed to build and cross-link it. A 2025 systematic review of eight trials found 15–30 g of collagen with at least 50 mg vitamin C may enhance tendon remodelling when combined with heavy resistance training (Collagen systematic review, JFMK 2025).
Metabolic health matters
Obesity and diabetes are linked with higher risk of tendinopathy, tears and ruptures (Nutrition and tendinopathy systematic review, JISSN 2022). For many people outside elite sport, improving overall diet and metabolic health may matter as much as any supplement.
Nutrient | Suggested approach | Strength of evidence |
Total energy | Don't under-eat during injury; match intake to training | Strong rationale, foundational |
Protein | Spread across meals; sports nutrition guidance commonly suggests about 1.6 g/kg/day for active people | Foundational, indirect tendon evidence |
Collagen or gelatin + vitamin C | 15–30 g collagen + ≥50 mg vitamin C, ~1 hour before loading | Promising, small trials |
Vitamin C (food) | Citrus, kiwifruit, capsicum, berries | Essential cofactor; deficiency harms collagen |
Omega-3 | Oily fish 2–3 times a week; supplement evidence modest | Weak to moderate |
Vitamin D | Test and correct deficiency; don't megadose | Weak; relevant if deficient |
Key points and when to get help
Rest isn't going to help long term, load is the medicine; the dose is what you adjust.
Speak to your clinician about pain education, and what is an appropriate pain scale for you.
At Move, we can help rule out other injuries, and provide progressive rehab programming to get you back in action whether its on the field or opening jars pain free.
References
Scott A, et al. ICON 2019: International Scientific Tendinopathy Symposium consensus: clinical terminology. Br J Sports Med 2020. Link
Millar NL, et al. Tendinopathy. Nature Reviews Disease Primers 2021. Link
Millar NL, Murrell GAC, McInnes IB. Inflammatory mechanisms in tendinopathy – towards translation. Nature Reviews Rheumatology 2017. Link
Cook JL, Purdam CR. Is tendon pathology a continuum? Br J Sports Med 2009. Link
Load management in tendinopathy: clinical progression for Achilles and patellar tendinopathy. Apunts Medicina de l'Esport. Link
Clifford C, et al. Effectiveness of isometric exercise in the management of tendinopathy: systematic review and meta-analysis. BMJ Open Sport Exerc Med 2020. Link
van der Vlist AC, et al. Isometric exercises do not provide immediate pain relief in Achilles tendinopathy. Scand J Med Sci Sports 2020. Link
Effects of anti-inflammatory (NSAID) treatment on human tendinopathic tissue. J Appl Physiol 2017. Link
Silbernagel KG, et al. Continued sports activity during rehabilitation in patients with Achilles tendinopathy. Am J Sports Med 2007. Link
Chimenti RL, et al. Midportion Achilles tendinopathy clinical practice guideline, revision 2024. JOSPT 2024. Link
Appraisal of the 2024 Achilles CPG. Journal of Physiotherapy 2025. Link
Liu Y, Li C, Yang F. Comparative effectiveness of exercise interventions for patellar tendinopathy: network meta-analysis. BMC Sports Sci Med Rehabil 2026. Link
Shockwave therapy for midportion and insertional Achilles tendinopathy: systematic review with meta-analysis. JOSPT 2026. Link
Coombes BK, Bisset L, Vicenzino B. Efficacy and safety of corticosteroid injections and other injections for management of tendinopathy. Lancet 2010. Link
PRP injections as second-line treatment in tendinopathy: systematic review and meta-analysis. Pain Medicine 2025. Link
Rehabilitation nutrition for tendon and ligament injuries. Healthcare 2026. Link
Collagen supplementation on tendon-related structural and performance outcomes: systematic review. J Funct Morphol Kinesiol 2025. Link
Synergistic effects of collagen peptides and vitamin C in tendinopathy rehabilitation: a critical review. Quality in Sport 2026. Link
van Dam L, et al. The JUMPFOOD study protocol. Trials 2023. Link
The impact of nutrition on tendon health and tendinopathy: a systematic review. J Int Soc Sports Nutr 2022. Link
