Achilles tendinopathy responds to load, and the evidence on this is now consistent enough that treatment protocols have converged. The 2019 BJSM consensus statement, drawing on randomised trials and systematic reviews, identifies progressive tendon loading as the first-line treatment, with eccentric exercise and heavy slow resistance both demonstrating clinically meaningful effect sizes. For the Indian runner with a clinically diagnosed Achilles tendinopathy, the treatment pathway is not mysterious. It is structured, time-bound, and well-evidenced.
This article is the protocol, broken into phases. Each phase has criteria for progression. The aim is to give you a defensible framework you can follow with or without supervision, while making clear when a clinician is necessary.
The principle: load is medicine
The current evidence does not support rest as the primary treatment for Achilles tendinopathy. A 2018 systematic review in Sports Medicine confirmed that progressive loading produces meaningfully better outcomes than rest at twelve weeks and twenty-six weeks. The mechanism is biological. Tendon adapts to load. Removing load removes the stimulus for adaptation. Pain in the early stages of loading is not a sign the tendon is failing; it is a signal to manage the load level, not to stop.
The research shows two loading approaches have the strongest evidence: the Alfredson eccentric heel drop protocol, published in 1998 and replicated extensively, and the heavy slow resistance protocol, developed by Beyer and colleagues in 2015. Both produce similar pain and functional outcomes at twelve weeks in mid-portion tendinopathy. Insertional tendinopathy responds better to modified protocols that avoid deep dorsiflexion.
Pain during loading: the 24-hour rule
A practical clinical principle from the consensus literature is the 24-hour rule. Pain during loading of up to five on ten on a numerical rating scale is acceptable if the pain returns to baseline within 24 hours. Pain that worsens beyond 24 hours indicates the load was excessive. This rule allows runners to self-monitor in a structured way without over-restricting or under-loading.
Phase 1: Isometric loading (Weeks 1 to 2)
The first phase is isometric calf holds. The research on isometrics in tendinopathy is mixed for the short-term analgesic effect, with some trials showing immediate pain reduction and others not, but isometrics are well-tolerated in highly irritable tendons and serve as an introduction to loading without the eccentric demand of later phases.
Protocol
Single-leg calf raise on a flat surface, hold at mid-range for 30 to 45 seconds. Five repetitions, four to five sets per day, with two minutes of rest between sets. The hold is at a level of effort that allows the full duration without form breakdown.
Progression criteria
Progress to Phase 2 when isometric holds can be performed at the prescribed duration with pain under five on ten, and when pain has not worsened over a 24-hour period for at least four consecutive days.
Phase 2: Eccentric or heavy slow resistance loading (Weeks 2 to 12)
The longest phase, and the one most directly responsible for tendon adaptation. The protocol you choose depends on equipment access and preference. Both have similar outcomes at twelve weeks.
Option A: Alfredson eccentric protocol
The classic protocol. Single-leg eccentric heel drops off a step. Lift onto the toes with the uninvolved leg, transfer weight, and lower slowly on the involved leg over three seconds, dropping the heel below the level of the step. Three sets of fifteen repetitions, twice daily, seven days a week, for twelve weeks. The discomfort during the exercise is part of the protocol, within the pain threshold described above. Load is added when bodyweight becomes easy, typically with a backpack.
For insertional tendinopathy, the heel drops should be performed on a flat surface, not off a step, to avoid deep dorsiflexion which provokes symptoms at the insertion.
Option B: Heavy slow resistance protocol
Bilateral seated or standing calf raises with substantial external load, typically using a barbell or machine. Three to four sets of six to fifteen repetitions, three times per week. Each repetition is performed slowly, three seconds up and three seconds down. Load is progressed weekly so that the prescribed repetition range remains challenging. Twelve-week duration.
The Beyer 2015 trial compared the two protocols head to head and found similar patient-reported outcomes at twelve weeks, with better patient satisfaction in the heavy slow resistance group. The choice between them is pragmatic. Heavy slow resistance requires gym access. Alfredson can be done at home.
Progression criteria within Phase 2
Load is progressed weekly when the previous week's load is tolerated with pain under five on ten and no worsening symptoms beyond 24 hours. The volume of running is allowed to increase in parallel, by 10 to 15 percent per week, provided the same pain criteria are met.
Phase 3: Energy storage and release (Weeks 6 to 16)
Once strength is rebuilt, the tendon needs reconditioning for the elastic energy demands of running. This phase introduces hopping, jumping, and plyometric drills, layered onto the ongoing strength work.
Protocol
Two sessions per week. Begin with bilateral pogo hops, 3 sets of 30 seconds. Progress to single-leg hops, then to single-leg bounding, then to faster running drills. Each progression is held for one to two weeks before advancing, with pain remaining under five on ten and not worsening beyond 24 hours.
Why this matters
Running is an elastic activity. The Achilles stores and releases energy at high rates. Strength alone does not prepare the tendon for those demands. Trials that include an energy-storage phase in rehabilitation show better return-to-running outcomes than strength-only protocols.
Phase 4: Return to running (Weeks 8 to 20)
Return to running is layered onto the loading programme, not done sequentially after it. Easy running at low volume can begin in Phase 2 once isometrics are tolerated and the 24-hour pain rule is consistently met.
Volume progression
The standard return-to-running protocol begins with walk-run intervals: 1 minute run, 1 minute walk, for 20 minutes, three times per week. Progress to continuous easy running over two to four weeks. Then add weekly volume at 10 to 15 percent per week, with a step-back week every fourth week.
What to avoid in early return
Speedwork, hill repeats, and downhill running stay off the menu until Phase 3 has been completed and the tendon tolerates plyometric loading. Premature return to high-intensity work is the most common cause of recurrence in clinical practice.
Adjuncts: what the evidence supports and what it does not
Many treatments are marketed for Achilles tendinopathy. The evidence for them is uneven.
What has reasonable evidence
Extracorporeal shockwave therapy has moderate evidence as an adjunct in chronic cases that have not responded to loading alone. Glyceryl trinitrate patches have evidence in some trials but with significant side effects. Heel lifts can be used in insertional tendinopathy as a short-term symptom reducer.
What has weak or mixed evidence
Platelet-rich plasma injections, stem cell therapy, sclerosing injections, and corticosteroid injections do not have consistent evidence to support routine use. Corticosteroid injections, in particular, have evidence of harm including tendon weakening, and the 2019 BJSM consensus recommends against them as a first-line treatment.
What about rest?
Complete rest is not supported by the evidence. Relative rest, meaning reduced running volume combined with continued loading and rehabilitation, produces better outcomes at twelve and twenty-six weeks than complete cessation.
Timeline expectations
Mild cases with early intervention often settle within six to twelve weeks. Chronic cases, defined as symptoms beyond three months at presentation, typically require four to six months of structured rehabilitation. Severe cases or those with imaging-confirmed structural pathology can take longer. The variable that predicts faster recovery in trials is adherence to the loading programme, not the choice of any single protocol.
When to escalate
If symptoms have not meaningfully improved after twelve weeks of structured loading at an appropriate dose, reassessment is warranted. A clinician with sports experience may consider imaging, adjuncts like shockwave therapy, or a referral to sports medicine. Persistent or worsening symptoms despite adherence may indicate an alternative diagnosis, structural rupture, or insertional pathology requiring modified management.
What to do next
For the exercise progressions as videos, the exercises library has the loading protocols. The recovery guide covers the return-to-running framework in more detail. For the broader injury context, the injuries hub covers the diagnostic picture. If your training pattern was the trigger, the STRIDD plan generator will draft a load curve that respects tendon-adaptation timescales. The wider Running Lab covers the Indian-runner injury and training landscape.