Alfredson Protocol for Achilles Tendinopathy: 12-Week Guide

Search for 'Achilles exercise' and most results show the same clip: rise onto your toes, lower slowly, thirty reps for three sets. But if you have put in six weeks of that and your heel is still tight and aching the moment you take your first step in the morning, the problem probably isn't effort. It is more likely that the routine you followed was never the protocol that produced the results you read about.

The original protocol, published in 1998 by Håkan Alfredson's team at Umeå University in Sweden, repeats only the eccentric (lengthening) phase of the calf raise, twice a day, 90 reps per session, 180 reps total. The concentric (pushing-up) phase is deliberately handed off to the other leg. Only the slow, 3-to-4-second lowering is kept as the loading stimulus. It shares a name with the symmetrical calf raise most people know, but the type of stimulus placed on the muscle is fundamentally different.

Fifteen patients with chronic Achilles tendinopathy who had been told they needed surgery returned to full, pain-free activity after this 12-week program alone, and that outcome is why the protocol has been cited as the standard reference in physical therapy for more than 25 years. This guide reproduces the original structure without modification: the week-by-week sets, the two foot positions, and the pain-tolerance thresholds are all carried over as designed. We will start with what separates it from a generic calf raise and why the number lands on 180 reps a day.

What the Alfredson Protocol Is: The Case for 180 Reps a Day

The Achilles tendon carries three to four times body weight during walking and six to eight times body weight during running and jumping, thousands of times a day. When this load outpaces the tendon's capacity to recover for months at a time, the collagen fibers inside the tendon lose their organized alignment, and neovessels and accompanying nerve fibers grow into tissue that is normally close to avascular. Once these changes take hold, the late-1990s sports medicine consensus held that treatments aimed only at the painful spot were less useful than an approach that reintroduces load to the tendon itself to drive remodeling.

Why eccentric loading alone was singled out

An eccentric contraction generates force while the muscle lengthens, so for a given weight it places more tension per muscle fiber and a stronger mechanical stimulus (mechanotransduction) at the tendon-muscle junction than a concentric contraction, which generates force while shortening. The research team's hypothesis was that this stimulus reactivates collagen synthesis in tenocytes while gradually causing the neovessels that had grown in alongside the pain to regress. Follow-up studies that tracked neovessel density with Doppler ultrasound have in fact observed a tendency for vessel density to decrease alongside pain reduction after eccentric training.

The original 1998 paper by Alfredson H, Pietilä T, Jonsson P, and Lorentzon R, published in the American Journal of Sports Medicine, enrolled 15 patients with chronic mid-portion Achilles tendinopathy (unilateral, average symptom duration around 18 months) who were awaiting surgery. Over 12 weeks, twice daily, they performed only eccentric calf raises in a straight-knee and a bent-knee position, 15 reps for 3 sets each, 180 reps total per day. All 15 patients returned to their prior activity level pain-free and avoided surgery. What makes the result more striking is the comparison arm: 15 matched patients who did concentric (standard push-up) training instead showed no improvement and all went on to surgery. The limitations remain real, though — a small sample of 15, a single center and single assessor, and no randomization.

There is also long-term follow-up. The same research group's Fahlström M, Jonsson P, Lorentzon R, and Alfredson H published a follow-up in Knee Surgery, Sports Traumatology, Arthroscopy in 2003, re-evaluating patients an average of 3.8 years after completing this protocol. Of 78 tendons with mid-portion tendinopathy, about 89% maintained a satisfactory result, but the insertional tendinopathy group had a satisfactory result in only 32%, confirming that outcomes diverge sharply by location. That gap is exactly why the original protocol should not be applied unmodified to insertional tendinopathy.

What a systematic review confirmed — and what it left unresolved

A systematic review by Sussmilch-Leitch SP and colleagues, published in BMC Musculoskeletal Disorders in 2012, synthesized the evidence for eccentric exercise in Achilles tendinopathy. Individual studies were generally positive, but the review noted that rep schemes, loading-progression methods, and assessment timepoints varied so much across studies that direct comparison was difficult, and that most exercise trials cannot be blinded, leaving residual risk of bias that could not be fully ruled out. In other words, eccentric exercise is well established as first-line treatment, but the number 180 itself is better read as a starting reference to adjust to individual pain response than as a fixed rule.

Exercise Technique and the 12-Week Week-by-Week Plan

How this differs from a generic calf raise

A typical calf raise pushes up with both feet (concentric) and lowers with both feet (eccentric) in a symmetrical repeated motion. That is useful for maintaining strength, but it does not match the goal of concentrating eccentric load on the tendon to drive remodeling. The Alfredson protocol removes the rising phase from the exercise entirely. The painful leg only ever 'holds and lowers,' and the return to the top is done with the other (healthy) leg or with arm assistance. This keeps the stimulus on the affected musculotendinous unit purely eccentric. Lowering speed differs too: a generic calf raise video usually rises and lowers in about 2 seconds, while this protocol deliberately stretches the lowering phase to 3 to 4 seconds to extend the time the muscle spends producing force while lengthening.

Three things separate the two. First, who performs the rising phase (both feet vs. the healthy leg only). Second, lowering speed (1-2 seconds vs. 3-4 seconds). Third, position split (mostly straight-knee vs. straight-knee and bent-knee given equal weight). If any one of these three is missing, the stimulus no longer matches what the original paper reported, so it is worth drilling these three before working through the table.

Exercise 1. Straight-Knee Eccentric Calf Raise (Targets the Gastrocnemius)

All you need is a step or stair edge and, if available, a wall or railing. Go barefoot or wear thin-soled indoor shoes — thick-cushioned running shoes dull the feedback from your forefoot on the step edge, making it harder to self-monitor knee angle and lowering speed.

Starting position — Stand with just the forefoot (ball of the foot) of both feet on the edge of a step or a 15-20cm platform, heels hanging free in the air. Keep the knee fully extended and rest your fingertips lightly on a wall or railing for balance only.

Movement steps — ① Rise onto both toes to the highest point. ② Shift your full weight onto the painful leg and lift the other foot slightly. ③ Keeping the knee straight, lower the heel slowly over 3-4 seconds to the lowest point below the step. ④ At the bottom, place the other (healthy) foot back on the step and rise with both feet to the top, then return to step ①.

Breathing — During the 3-4 second lowering, don't hold your breath — inhale slowly through the nose while controlling the descent, then exhale through the mouth as you rise with both feet.

Sets and frequency — 15 reps × 3 sets, twice a day (for example, right after waking and before bed), resting 30-60 seconds between sets.

Common mistakes and fixes — The most frequent error is bending the knee slightly to avoid loading the gastrocnemius. Check your side profile in a mirror, or lightly rest your back against a wall to monitor knee angle. If the descent takes under a second, the eccentric stimulus is lost — counting out loud, 'one-two-three-four,' as you lower helps. Rising back up on the painful leg is another common mistake; the ascent must always be done with the other leg or arm assistance to preserve the eccentric-only principle.

Stop signs — If pain exceeds 5 out of 10, you hear a pop at the back of the heel during the movement, or next-morning stiffness is clearly worse than the day before, stop for the day and drop back to the prior load stage.

Exercise 2. Bent-Knee Eccentric Calf Raise (Targets the Soleus)

Starting position — Same step as Exercise 1, but start with the knee bent roughly 20-30 degrees. Keep the torso upright and hold the knee-bend angle constant throughout the descent.

Movement steps — ① Rise to the top with both feet, knee bent. ② Shift weight onto the painful leg. ③ Keeping the knee angle constant, lower the heel over 3-4 seconds to the lowest point. ④ Rise back up with the other leg and return to the starting position.

Breathing — Same as Exercise 1: inhale during the descent, exhale during the ascent.

Sets and frequency — 15 reps × 3 sets, twice a day. Perform this immediately after Exercise 1; combined across both positions, twice daily, the full session totals 180 reps a day.

Common mistakes and fixes — The knee angle often straightens mid-set, which effectively turns this into Exercise 1 and undertrains the soleus. Resting a hand lightly on the knee to feel any angle change makes this easy to correct. Leaning the torso forward to use momentum is another common error — keep the pelvis directly above the step and lower with pure muscular control, without any bounce.

Stop signs — Same as Exercise 1. If pain is notably worse specifically in the bent-knee position, the cause may be limited ankle dorsiflexion range rather than the soleus itself, so check your stretching routine first.

If it is insertional tendinopathy, modify like this

The over-extension phase of dropping the heel below the step can worsen pain in insertional tendinopathy (at the calcaneal attachment). In that case, perform both exercises on flat ground without a step, limiting the range so the heel never drops below floor level. A Haglund deformity is often present alongside insertional tendinopathy, so avoid stiff or low-backed heels.

The 12-Week Week-by-Week Plan

The table below keeps the original protocol's 180-reps-per-day structure intact and only varies when load is added, week by week. If pain stays in the 3-4 out of 10 range, move to the next week as scheduled; if it exceeds 5 out of 10, drop back to the prior week.

If a weighted backpack is impractical, a water bottle or sandbag works just as well for adjusting load. The core principles that matter more than the exact weight are a 3-4 second descent, keeping pain at 3-4 out of 10 or below, and hitting 180 reps a day across both positions for the full 12 weeks.

If you don't have a proper step

If there is no suitable step at home, stacking thick phone books or yoga blocks to a height of 15-20cm works fine. Just check the surface doesn't slip and that it holds steady under your forefoot with both feet before you start. A slant board or calf raise machine at a gym also works, but whichever tool you use, keep both core principles: a 3-4 second descent and using the other leg to rise.

Where NIR wellness care fits in

Many people condition the Achilles and calf area with 5-10 minutes of near-infrared light before the protocol and re-irradiate for 10-15 minutes afterward. This should be treated as a supportive routine that helps with local conditioning before and after the session, not as a substitute for the eccentric exercise itself.

Reading Your Progress and Maintaining Gains

Because eccentric exercise works by stimulating the slow biological process of collagen remodeling, jumping straight back to pre-injury running or jumping intensity as soon as pain drops carries a high risk of recurrence. After finishing the 12 weeks, check that you have cleared all four of the criteria below before ramping back up.

Logging separates a plateau from real progress

Record your pain score and stiffness duration at the same time each week (right after waking is a good default), and every two weeks log your max single-leg calf raise reps. If the numbers haven't budged for four straight weeks, it is usually worth checking whether your descent speed or knee-angle separation has drifted before adding more weight. A large share of the questions we hear are some version of 'I'm five weeks into the protocol and it's not working,' and when people send video, the descent is often under a second, or the painful leg is doing the ascent. Hitting the rep count matters less than holding the three principles — a 3-4 second descent, eccentric-only on the painful leg, and keeping the two positions distinct.

If you are starting after 40, slow the pace down

The same 12-week table shouldn't necessarily move at the same speed for a runner in their 30s and a hiker in their 50s. Tendon collagen turnover tends to slow with age, so if you are starting in your late 40s or older, it is safer to stretch each 3-week loading block out to 4-5 weeks and watch the pain response for an extra day or two before advancing to the next weight. The table itself doesn't change — only how long you stay in each block.

The common week-6 plateau

It is not unusual to progress the backpack weight smoothly through week 3, then notice pain tick back up from 4 to 5 around week 6. Early pain relief tends to reflect nervous-system adaptation (a raised pain threshold to load), while actual collagen remodeling ramps up more fully after around week 6 — the overlap of these two processes can produce this temporary setback. Rather than dropping the weight sharply, staying at the prior week's load for one more week and reassessing usually works better.

Don't stop training after full return

Even in patients whose initial results were good, Fahlström M et al.'s (2003) long-term follow-up documented pain recurring over time. After returning to sport pain-free, continuing a maintenance program at half the set count (15 reps × 1-2 sets per position) two to three times a week for at least 3-6 months helps prevent recurrence. Runners should also keep weekly training-volume increases under 10%, and avoid making sudden changes to heel height when switching shoes.

If there is no improvement after 12 weeks

If you have followed the original protocol faithfully for 12 weeks or more — descent speed, eccentric-only on the painful leg, weekly loading as scheduled — and still see no clear improvement, it is worth checking with an orthopedic surgeon or sports medicine physician whether this is actually insertional tendinopathy being treated with a mid-portion approach, or whether next-step treatments such as extracorporeal shockwave therapy (ESWT) or ultrasound-guided injection are needed. Eccentric exercise itself is usually continued alongside these treatments.

Contraindications and Warning Signs

Do not start this protocol if (contraindications)

• A suspected Achilles rupture (see the emergency signs below) — rupture must be ruled out first.
• A corticosteroid injection into the Achilles area within the past 4-6 weeks — the tendon tissue is weakened and rupture risk is elevated.
• Recent or current use of fluoroquinolone antibiotics (such as ciprofloxacin) — these carry a known Achilles rupture risk, so discuss high-intensity eccentric loading with your physician first.
• An acute partial or complete rupture confirmed on imaging — this protocol is for chronic tendinopathy and does not apply to acute rupture.
• Reduced foot sensation from diabetic neuropathy or similar conditions, making it hard to accurately gauge pain signals — since this protocol relies on pain as the loading guide, proceed only under professional supervision in this case.

Precautions when combining with NIR light

• Never irradiate the eyes directly; use protective goggles if needed.
• If taking photosensitizing medications (tetracyclines, amiodarone, etc.), consult your physician before use.
• Discontinue immediately if persistent redness, blistering, or other adverse skin reactions occur.
• If skin sensation is reduced (e.g., from diabetes), set conservative distance and duration to avoid burn risk.

Signs requiring you to stop the exercise immediately

If you feel a sudden, severe pain accompanied by a 'pop' sound during a set, if the strength to lift your heel suddenly gives out, or if you feel a distinct gap when you palpate the back of the calf, stop immediately and seek emergency orthopedic care. If, lying face down, squeezing the calf (the Thompson test) fails to produce any automatic foot movement, that is also a sign suggestive of rupture — go to the hospital rather than continuing to self-manage. NIR wellness care cannot substitute for medical care in this situation.

When self-management alone is not enough

Get an evaluation from a physical therapist or sports medicine physician before completing the full 12 weeks if any of the following apply: pain has not decreased at all after 4+ weeks of following the protocol correctly; numbness or altered sensation extends to the ankle or top of the foot; you cannot reliably tell insertional from mid-portion tendinopathy on your own; or you have a chronic connective-tissue condition such as rheumatoid arthritis. In these situations, it is best to confirm tendon thickness, any partial tear, and the degree of neovascularization via ultrasound or MRI before redesigning the program.

Pregnancy, breastfeeding, and lower-limb vascular conditions

If you are pregnant or have a history of lower-limb vascular conditions such as deep vein thrombosis, discuss the higher-load phase of the backpack progression (week 7 onward) with your physician before proceeding. Significant varicose veins can also make prolonged standing repetitions uncomfortable — consider longer rest between sets or a seated alternative exercise.