Eccentric Exercise Protocol for Chronic Achilles Tendinitis
For chronic Achilles tendinopathy, use the Alfredson protocol: perform 3 sets of 15 repetitions of eccentric heel drops twice daily (morning and evening) for 12 weeks, doing the exercise both with a straight knee and with a bent knee, progressing load when exercises become pain-free 1.
The Alfredson Protocol Details
The standard protocol involves:
- Frequency: Twice daily (morning and evening), 7 days per week
- Duration: 12 weeks minimum
- Repetitions: 3 sets of 15 repetitions per session
- Knee positions: Perform exercises BOTH with straight knee (targets gastrocnemius) AND bent knee (targets soleus)
- Speed: Slow, controlled movements
- Load progression: Increase weight when exercises can be performed without pain
- Pain approach: Exercises should be performed through mild discomfort initially
1 provides strong evidence for this protocol, which has become the gold standard for eccentric training in Achilles tendinopathy.
How to Perform the Exercise
Stand on the edge of a step or raised platform. Rise up on both feet to the starting position (plantarflexion), then remove the unaffected leg and slowly lower the affected heel below the level of the step (dorsiflexion) over 3 seconds. Use the unaffected leg to return to the starting position. This constitutes one repetition.
Important Modifications Based on Location
For insertional Achilles tendinopathy (pain at the heel attachment), modify the protocol to avoid full dorsiflexion, as loading into dorsiflexion shows poor results (only 32% success rate) 2. Instead, perform eccentric exercises on flat ground rather than off a step, avoiding the stretch component at the insertion point. This modification achieved 67% satisfaction rates 2.
For mid-portion Achilles tendinopathy (pain 2-6 cm above the heel), the standard Alfredson protocol with full dorsiflexion off a step is appropriate and shows excellent results (80-86% satisfaction) 3, 4.
Gradual Onset Approach
Strong evidence supports gradually building up to the full protocol during the first week 1. Start with fewer repetitions or sets and progress to the full 3×15 twice daily regimen as tolerated, though specific progression parameters vary across studies.
Expected Timeline and Outcomes
- Pain reduction: Significant improvement typically seen by 6 weeks 4
- Return to activity: Average 10 weeks for mid-portion tendinopathy 3
- Full protocol duration: 12 weeks minimum
- Pain scores: Expect VAS reduction from ~7/10 to ~2-3/10 by 6 weeks 3
Critical Caveats
The evidence shows eccentric training is safe and does not harm tendon microcirculation 5. However, recent high-quality evidence 6 from 2026 suggests that unsupervised home-based eccentric training may have limited effectiveness, showing only 4-point difference versus sham exercise. This highlights the importance of proper instruction, monitoring, and potentially supervised sessions initially.
Common pitfall: Patients often discontinue exercises too early or fail to progress load appropriately. The protocol requires commitment to twice-daily exercises for 12 weeks, which can be challenging for adherence.
The 2024 AOPT clinical practice guideline 7 supports eccentric exercise as a primary intervention, reinforcing this as the evidence-based standard of care alongside the 2005 American Family Physician guideline 8 that first established eccentric exercise as beneficial for Achilles tendinopathy.