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Can You Train With Achilles Tendinopathy? The Continue-Anyway Audit: Where Silbernagel's Randomized Trial Let One Group Keep Running and Jumping Through Rehab Under a Pain-Monitoring Model and Watched Them Match the Rested Group at Every Time Point (VISA-A 57→85 Continuing vs 57→91 Resting at Twelve Months), Where Alfredson's Heavy Eccentric File Returned All Fifteen Runners to Preinjury Levels While the Fifteen Conventionally Rested All Failed Into Surgery, and Mafi's Multicenter Randomized Pair Put Eccentric at 82% Satisfied Against Concentric's 36%, Where Beyer's Heavy Slow Resistance Arm Matched the Eccentric File Outcome-for-Outcome While Remodeling Tendon Thickness and Neovessels on Ultrasound and Winning Compliance 92% to 78%, Where Khan's Biopsies Found No Inflammatory Cells to Rest Away and Cook–Purdam's Continuum Replaced Tendinitis With Load Dose, Where Jonsson's Insertional Variant Punished Dorsiflexion Loading (32% Good) and Rewarded Avoiding It (67%), Where the Five-Year Files Land at 80% Fully Recovered on Exercise Alone and Paavola's Eight-Year Ledger Sits at 94% Asymptomatic-or-Mild With Ultrasound Changes Refusing to Track Symptoms, de Vos's Saline-Controlled PRP Null, and the 2025 Consensus Files From Six Medical Red Flags to the Two Programming Dials That Matter: the Tendon Heals by Dose, Not by Rest

By RightRep AI Assistant · · 20 min read

There is a fence at the top of this post and it outranks everything below it: a sudden pop in the back of the ankle followed by an inability to push off, stand on tiptoe or walk normally is a suspected tendon rupture — emergency assessment today, not a programming question; rupture is the first of the six conditions the 2025 international Delphi consensus flags as requiring further medical attention [15]. The second fence: tendinopathy with a systemic companion — diagnosed inflammatory joint disease, metabolic syndrome, familial hypercholesterolaemia, endocrine or hormonal disorders, or a drug reaction such as fluoroquinolone antibiotics — is a clinician conversation, because all five made the same consensus list, and the tendon that starts hurting three weeks into a ciprofloxacin course is a different file from the one that started hurting after a mileage jump [15]. The third fence: midportion and insertional tendinopathy are different addresses with different rules — the 2–6 cm above the insertion that dominates the trial file, versus the insertion itself where loading into full dorsiflexion is the specific trap [1][9]. And one honesty clause that outranks both internet camps: the trials below bought pain relief, function and return to sport with load — none of them normalized every tendon on ultrasound, symptoms outlasted structure in both directions, and "mild pain may remain" is the five-year file's own closing sentence [7][11]. With the fences respected, the question underneath is the gym's most misunderstood injury: the resting script ("it's inflamed — rest it, ice it, anti-inflammatory it, and don't load the calf until it's pain-free") versus the passive-therapy script ("injections, shockwave, and surgery if the rest fails"). The first script is contradicted by the tendon's own histology; the second by its own controlled trials. The evidence grades both of them down — and grades the barbell up.

The short answer: train — the tendon's medicine is dose, not rest

Strip the file to its spine. The diagnosis itself removes the resting script's foundation: the biopsies of symptomatic Achilles tendons show disorganized collagen and mucoid ground substance with capillary proliferation, and their most consistent finding is the absence of inflammatory cells — this is tendinosis, a load-adaptation problem wearing an inflammation costume, which is why the field retired the word tendinitis [3]. The continue-anyway result is the discipline's cleanest training-through finding: Silbernagel randomized 38 patients to identical rehabilitation plus either continued running and jumping under a pain-monitoring model or six weeks of active rest — and found no significant differences in rate of improvement at any time point, with the continuing group's VISA-A going 57→85 and the rested group's 57→91 over twelve months [5]. The loading menu is deep and redundant: all fifteen of Alfredson's eccentrically trained runners returned to preinjury levels while all fifteen conventionally rested comparison athletes failed into surgery [1]; Mafi's randomized pair put eccentric at 82% satisfied against concentric's 36% [2]; and Beyer's trial showed heavy slow resistance matching the eccentric protocol outcome-for-outcome, both remodeling tendon thickness and neovascularization on ultrasound, with the slower heavier protocol winning compliance 92% to 78% [8]. The passive add-ons buy nothing the loading isn't already buying: PRP against saline on top of eccentric exercises improved VISA-A by 21.7 versus 20.5 points — an adjusted difference of −0.9 [10]. And the long game is better than the fear suggests: 80% fully recovered at five years on exercise alone [6], 94% asymptomatic or with only mild pain under strenuous load at eight years [11]. The verdict writes itself: don't rest the tendon into weakness — re-dose it. The calf work you already do is the treatment; the skill is the dosage [5][8][16].

Who is asking: the scale file

This is the largest tendon in the body carrying one of sport's most common overuse files, and the census runs on three levels. In the general population, de Jonge's primary-care registry of 57,725 persons puts midportion Achilles tendinopathy at 1.85 per 1,000 registered patients per year — 2.35 per 1,000 among adults aged 21–60 — with a sports relationship recorded in only 35% of cases [12]: two-thirds of the file never came from sport, and the authors' own caveat is that the true count is likely higher. Among runners, the file moves to the front of the queue: the São Paulo Running Injury Group's systematic review of eight studies and 3,500 runners ranks Achilles tendinopathy a top-three running injury — incidence 9.1–10.9%, prevalence 6.2–9.5%, behind only medial tibial stress syndrome — and the number-one injury of ultramarathon runners [13]. And the risk file has a headline that every reader of this library already suspects: Saragiotto's review of eleven prospective cohorts and 4,671 runners, spanning sixty investigated factors, found previous injury in the last twelve months to be the main risk factor, with no gender association in most studies [14] — the strongest predictor of the next tendinopathy is the last one, which is exactly why the eight-year ledger's finding that 41% of patients developed overuse symptoms in the initially uninvolved tendon belongs in the training log, not the footnotes [11]. This library has audited the joint above (the knee and squatting, the knee and running), the meniscus, the ACL, the rotator cuff and the elbow's tendon — the tendon the barbell loads with every calf raise, jump and stride was the last unopened door.

What the name is telling you: the no-inflammation file

The resting script is built on a word — tendinitis — that the tendon's own histology demolished a quarter-century ago. Khan's review of biopsy studies across Achilles, patellar, tennis-elbow and cuff tendons is the founding document: healthy tendon is glistening white, its collagen in tightly packed parallel bundles; symptomatic tendon is grey and amorphous, its fibers discontinuous and disorganized, ground substance increased, tenocytes plump and chondroid, capillaries proliferative — and the most significant feature is the absence of inflammatory cells [3]. That single sentence retires three treatment families at once: rest-as-cure (there is no inflammation to settle), NSAIDs-as-primary (no target), and wait-for-pain-free (the tissue needs load signals to reorganize, and pain-free waiting delivers none). The paper's own recommendation — call it tendinopathy, the clinical umbrella — is the field's standard vocabulary today [3]. Cook and Purdam then gave the pathology its map: a continuum from reactive tendon (a transient load-response that settles when the dose settles) through tendon dysrepair to degenerative change — different stages on one road, which is why two lifters with identical scans can need different doses, and why the same tendon can be sore at 24 and silent at 44 [4]. The pairing with the elbow's overuse audit is deliberate: that file reached the same verdict from the tennis court, this one reaches it from the calf machine. What both files refuse is the inflation of "not inflamed" into "not injured" — the tendon is asking for a different dose, not for denial [3][4][5].

The rulebook door: what the 2025 consensus actually says

Two consensus files landed in 2025 and they bookend the practical middle of this post. Malliaras's five-round Delphi with 52 international participants defined how the diagnosis is actually made — four essential domains, none of them an imaging finding: pain location (93% agreement), pain during activity (97%), tests that provoke pain (87%), and palpation (83%) [15]. The same panel listed fifteen differential diagnoses that masquerade as Achilles pain — partial tear, posterior ankle impingement, plantaris tendinopathy, paratendinopathy, the bursas, Haglund's exostosis, calcaneal stress reaction, Sever's disease in the young — and the six conditions requiring further medical attention quoted in the fence above [15]. The second consensus asked a different question — which exercise parameters actually matter — and Demangeot's three-round Delphi with seventeen international experts returned the coaching manual in two lines: for midportion tendinopathy, the intensity of contraction was ranked the most influential parameter, with total time under tension, the number of repetitions and sets, and the type of contraction reaching consensus; for insertional tendinopathy, the range of ankle dorsiflexion during the exercise was ranked most important [16]. Read together, the two papers convert "do your heel drops" from folk remedy into programming: locate the pain, name the address, respect the red flags — then dial the load by intensity (midportion) or by range (insertional) like any other training variable [15][16].

The trial spine: the continue-anyway RCT

Every audit family has one trial that anchors the whole post; this file's is Silbernagel's 2007 randomized study, and it deserves its exact reading. Thirty-eight patients with Achilles tendinopathy were randomized to identical progressive calf-tendon rehabilitation, differing in one variable: the exercise-training group was allowed to continue Achilles-tendon-loading activity — running and jumping — using a pain-monitoring model, while the active-rest group had to stop such activities for the first six weeks [5]. The pain-monitoring model is the quiet hero of the design: pain is scored 0–10, allowed to reach moderate levels during activity provided it settles by the next morning and the week-over-week trend is flat-to-falling — a dosage rule, not a prohibition [5]. The result is the sentence the resting script cannot survive: no significant differences between the groups in the rate of improvement — the continuing group improved VISA-A-S from 57 to 85, the resting group from 57 to 91, both P<.01, with the between-group gap never significant [5]. The authors' conclusion, quoted plainly: no negative effects could be demonstrated from continuing tendon-loading activity with the pain-monitoring model, and continued pain-monitored training "might therefore represent a valuable option" [5]. The five-year follow-up sharpened the same point from the other side: kinesiophobia — fear of movement — correlated −0.590 with heel-rise work recovery, and the authors' recommendation was explicit that a pain-monitoring model should be used because avoiding movement has a measurable cost [6]. For the lifter holding a sore Achilles over a scheduled leg day: the question the file answers is not whether to train but what dose the morning-after rule permits [5][6].

The loading menu: eccentric, heavy slow resistance, and the insertional variant

The menu's founding item is Alfredson's 1998 protocol: fifteen recreational athletes around 44 years old with chronic tendinosis, twelve weeks of heavy-load eccentric calf training — heel drops lowering the weight on one leg, rising on the other, three sets of fifteen, twice daily, seven days a week, loaded progressively until the exercise stopped being painful — and all fifteen returned to their preinjury running levels [1]. The same paper carries the control group that made history: fifteen matched athletes treated conventionally — rest, NSAIDs, shoe changes, orthoses, physical therapy — in no case successfully; all were ultimately treated surgically [1]. Mafi's multicenter randomized trial then did the comparison properly: forty-four patients, eccentric versus concentric, the same twice-daily twelve-week calendar, patients instructed to train despite pain or discomfort — 82% of the eccentric group satisfied and back to previous activity versus 36% of the concentric group (P<0.002) [2]. Two decades later Beyer tested the menu's modern item: heavy slow resistance — leg-press and calf-machine work in a progressive-overload ramp from three sets of 15RM down to four sets of 4RM across twelve weeks, three sessions a week instead of fourteen — against the eccentric protocol in fifty-eight patients: no between-group difference in VISA-A or pain at 12 or 52 weeks, tendon thickness and neovascularization significantly reduced in both groups, satisfaction trending HSR's way (100% vs 80%, P=.052), and compliance decisively so: 92% versus 78% (P<.005) [8]. The insertional address rewrites one rule: loading into full dorsiflexion — the bottom of the classic heel drop — had produced good results in only 32% of insertional patients, and Jonsson's modified regimen performed without dorsiflexion loading returned 67% of patients to previous activity with pain falling from 69.9 to 21 on the visual analog scale [9]. The synthesis is the family's most actionable sentence: the tendon responds to heavy, slow, progressive load — the midportion dose dial is intensity, the insertional dose dial is range [8][9][16]. Which is to say: the calf machine was never the problem; the prescription was.

The long game: five years and eight years

Because tendinopathy's reputation is chronicity, the long files carry unusual weight — and both run in the same direction. Silbernagel's five-year follow-up of exercise-only treatment (no injections, no surgery) found 80% of patients fully recovered — 65% with no symptoms at all — while only 20% continued symptomatic and just two patients had sought any other treatment [6]. Van der Plas's five-year audit of the classic heel-drop program in forty-six patients tells the honest twin: VISA-A climbed from 49.2 to 83.6 (P<0.001), 39.7% were completely pain-free, but 48.3% had sought one or more additional treatments along the way, and tendon thickness had barely moved (8.05→7.50 mm, P=0.051) — improvement is the norm, patience is the price, and mild pain may remain [7]. Paavola's eight-year observational ledger of eighty-three conservatively-treated patients sets the ceiling and the two caveats: 94% asymptomatic or with only mild pain under strenuous exercise, 84% with full recovery of activity level — with 29% having crossed to surgery somewhere in the eight years, and 41% having developed overuse symptoms in the initially healthy tendon [11]. And the imaging honesty closes the loop the same way every audit in this family has: ultrasonographic changes were frequent in both the involved and the initially uninvolved tendons, and their occurrence was not clearly related to the patients' symptoms [11] — the same lesson as the labrum, the meniscus and the disc: the scan is one witness, the load-response is the verdict. Structured loading is the through-line of every good outcome in the file; the second tendon is a surveillance item, not a superstition [6][7][11][14].

The injection door: what the saline-controlled trial showed

The passive door's best-controlled test is also its cleanest null. De Vos randomized fifty-four patients to eccentric exercises plus either a platelet-rich plasma injection or a saline injection — double-blind, complete follow-up, the works [10]. At 24 weeks, the PRP group's VISA-A had improved by 21.7 points and the saline group's by 20.5; the adjusted between-group difference was −0.9 (95% CI −12.4 to 10.6), and the confidence interval did not come near the predefined threshold of 12 points that would have made PRP worth having [10]. Read what the saline arm actually was: a placebo injection sitting on top of a loading program that delivered twenty points of improvement on its own — the syringe added nothing, which means the exercise did everything [10]. That result rhymes with the elbow file's PRP null and completes this family's pattern: the interventions that survive their control groups are all forms of progressive tendon loading [8][10]. The surgical door exists and is real for the minority who exhaust the loading menu — Paavola's 29% crossed to it within eight years [11] — but its proper address is after a genuinely completed, genuinely progressive, genuinely logged program, which is precisely what most "I tried everything" files turn out not to have contained [1][6][7][8]. The practical translation: money and needles are not dose [10].

So what do you actually do? The practical file

Six rules, every one sourced from the files above:

  1. Run the fence first. A pop with lost push-off is rupture territory — emergency assessment today [15]. Systemic disease, metabolic syndrome, high cholesterol, endocrine disorders or a fluoroquinolone course behind a new Achilles pain belongs to a clinician, not to this protocol [15]. A child's heel pain at the growth plate is Sever's — an age-specific file [15].
  2. Name the address before you load it. Midportion (2–6 cm above the insertion) and insertional are different tendons with different rules: intensity is the midportion's dose dial, dorsiflexion range is the insertional's [9][16]. Loading the insertion through full dorsiflexion is the specific trap the trial file punished [9].
  3. Do not rest it into weakness — re-dose it. The histology has no inflammation to rest away [3]; the continue-anyway RCT matched rest at every time point [5]; the conventionally-rested comparison group of the founding study all failed into surgery [1].
  4. Run a real loading block — and log it. Twice-daily eccentric or three-weekly heavy slow resistance for twelve weeks, both proven, HSR easier to actually do (92% vs 78% compliance) [1][2][8]. The rep-and-set arithmetic of the calf ramp follows the same progressive overload calendar as any mesocycle — the difference is the pain-monitoring budget, not the anatomy [5].
  5. Use the pain-monitoring budget, not the pain-free fantasy. Pain up to moderate during the session is permitted when it settles by the next morning and the weekly trend is flat-to-falling [5]; the five-year file's own warning is that fear of movement measured against recovery (r=−0.590) is a treatment variable [6]. The passive add-ons are not: PRP's saline-controlled null is the file's plainest number [10].
  6. Respect the calendar and the second tendon. Improvement is measured in months and its floor is high — 80% recovered at five years on exercise alone [6], 94% asymptomatic-or-mild at eight [11] — but 41% of the eight-year file developed symptoms in the other Achilles [11], and previous injury is the running file's main risk factor [14]. Train, track and dose both tendons; that is the whole audit.

How RightRep fits into this

The Achilles question is ultimately a dose-response question — which load, which week, which morning-after reading — and it is unanswerable without a record:

  • The pain×load ledger. Every session lands with load, reps and per-rep quality scores; beside a dated symptom note it turns "calf work sometimes aches" into the exact exercise-intensity-week curve the pain-monitoring model actually runs on [5] — the trend line is the dosage rule.
  • Camera-counted honesty around the modified lift. A range-limited or intensity-reduced block only screens properly if the substitute work is real — rep-counted, rep-scored form checks keep the modified heel raise from quietly becoming no heel raise, the same honesty every range decision in this library demands.
  • The twelve-week block, tracked like a block. The trial protocols are structured progressive programs with defined endpoints [1][8] — the same tracked-mesocycle discipline any training-frequency decision runs on, with the surgical consultation parked at the end of a completed log instead of at the start of an empty one [7][11].

The bottom line

  • The name: no inflammatory cells in the biopsies — tendinosis, not tendinitis; the field's own recommendation is the word tendinopathy [3], staged on Cook–Purdam's reactive→dysrepair→degenerative continuum [4].
  • The spine: continued running and jumping under a pain-monitoring model matched active rest at every time point — VISA-A 57→85 continuing vs 57→91 resting, no significant differences [5].
  • The menu: eccentric 15-for-15 with all fifteen conventionally-rested controls failing into surgery [1]; 82% vs 36% against concentric [2]; HSR equal with 92% vs 78% compliance and both remodeling thickness and neovessels [8]; insertional 67% without dorsiflexion vs 32% with it [9].
  • The passive door: PRP vs saline on top of eccentric exercises — 21.7 vs 20.5 points, adjusted difference −0.9 [10].
  • The long game: 80% fully recovered at five years on exercise alone [6]; 94% asymptomatic-or-mild at eight years with 29% crossed to surgery and 41% other-side incidence [11]; 39.7% pain-free and 48.3% shopping for add-ons in the heel-drop five-year audit [7].
  • The census: 1.85 per 1,000 in the general population (2.35 in adults 21–60, only 35% sport-related) [12]; a top-3 running injury at 9.1–10.9% incidence and #1 in ultramarathon [13]; previous injury the main risk factor [14].
  • The rulebook: four diagnostic domains, none of them imaging [15]; six medical red flags from rupture to fluoroquinolones [15]; contraction intensity (midportion) and dorsiflexion range (insertional) ranked the programming dials that matter [16].

Load the tendon like it's the treatment — because it is — and let the camera keep the reps honest at rightrep.app.

This post was written by the RightRep AI Assistant — the same AI that counts and scores your reps at rightrep.app.

Sources

  1. Alfredson H, Pietilä T, Jonsson P, Lorentzon R. Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. American Journal of Sports Medicine, 1998;26(3):360–366. pubmed.ncbi.nlm.nih.gov
  2. Mafi N, Lorentzon R, Alfredson H. Superior short-term results with eccentric calf muscle training compared to concentric training in a randomized prospective multicenter study on patients with chronic Achilles tendinosis. Knee Surgery, Sports Traumatology, Arthroscopy, 2001;9(1):42–47. pubmed.ncbi.nlm.nih.gov
  3. Khan KM, Cook JL, Bonar F, Harcourt P, Aström M. Histopathology of common tendinopathies. Update and implications for clinical management. Sports Medicine, 1999;27(6):393–408. pubmed.ncbi.nlm.nih.gov
  4. 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. pubmed.ncbi.nlm.nih.gov
  5. Silbernagel KG, Thomeé R, Eriksson BI, Karlsson J. Continued sports activity, using a pain-monitoring model, during rehabilitation in patients with Achilles tendinopathy: a randomized controlled study. American Journal of Sports Medicine, 2007;35(6):897–906. pubmed.ncbi.nlm.nih.gov
  6. Silbernagel KG, Brorsson A, Lundberg M. The majority of patients with Achilles tendinopathy recover fully when treated with exercise alone: a 5-year follow-up. American Journal of Sports Medicine, 2011;39(3):607–613. pubmed.ncbi.nlm.nih.gov
  7. van der Plas A, de Jonge S, de Vos RJ, van der Heide HJ, Verhaar JA, Weir A, Tol JL. A 5-year follow-up study of Alfredson's heel-drop exercise programme in chronic midportion Achilles tendinopathy. British Journal of Sports Medicine, 2012;46(3):214–218. pubmed.ncbi.nlm.nih.gov
  8. Beyer R, Kongsgaard M, Hougs Kjær B, Øhlenschlæger T, Kjær M, Magnusson SP. 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. pubmed.ncbi.nlm.nih.gov
  9. Jonsson P, Alfredson H, Sunding K, Fahlström M, Cook J. New regimen for eccentric calf-muscle training in patients with chronic insertional Achilles tendinopathy: results of a pilot study. British Journal of Sports Medicine, 2008;42(9):746–749. pubmed.ncbi.nlm.nih.gov
  10. de Vos RJ, Weir A, van Schie HTM, Bierma-Zeinstra SM, Verhaar JA, Weinans H, Tol JL. Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial. JAMA, 2010;303(2):144–149. pubmed.ncbi.nlm.nih.gov
  11. Paavola M, Kannus P, Paakkala T, Pasanen M, Järvinen M. Long-term prognosis of patients with achilles tendinopathy. An observational 8-year follow-up study. American Journal of Sports Medicine, 2000;28(5):634–642. pubmed.ncbi.nlm.nih.gov
  12. de Jonge S, van den Berg C, de Vos RJ, van der Heide HJ, Weir A, Verhaar JA, Bierma-Zeinstra SM, Tol JL. Incidence of midportion Achilles tendinopathy in the general population. British Journal of Sports Medicine, 2011;45(13):1026–1028. pubmed.ncbi.nlm.nih.gov
  13. Lopes AD, Hespanhol Júnior LC, Yeung SS, Costa LO. What are the main running-related musculoskeletal injuries? A Systematic Review. Sports Medicine, 2012;42(10):891–905. pubmed.ncbi.nlm.nih.gov
  14. Saragiotto BT, Yamato TP, Hespanhol Junior LC, Rainbow MJ, Davis IS, Lopes AD. What are the main risk factors for running-related injuries? Sports Medicine, 2014;44(8):1153–1163. pubmed.ncbi.nlm.nih.gov
  15. Malliaras P, Gravare Silbernagel K, de Vos RJ, et al. Diagnostic domains, differential diagnosis and conditions requiring further medical attention that are considered important in the assessment for Achilles tendinopathy: a Delphi consensus study. British Journal of Sports Medicine, 2025;59(13):891–901. pubmed.ncbi.nlm.nih.gov
  16. Demangeot Y, O'Neill S, Degache F, et al. Exercise parameters to consider for Achilles tendinopathy: a modified Delphi study with international experts. British Journal of Sports Medicine, 2025;59(19):1337–1349. pubmed.ncbi.nlm.nih.gov