Understanding Achilles Tendinopathy — Why Progressive Loading Beats Rest for Recovery

Achilles tendinopathy affects many runners, causing pain and stiffness in the Achilles tendon. Despite common advice to rest, research shows that resting alone can actually make this condition worse. Tendons need the right kind of mechanical load to heal properly. This post explains why progressive loading is the best approach to recovery and how it helps runners get back on track.

What Is Achilles Tendinopathy?

Achilles tendinopathy is an overuse injury that affects the tendon connecting the calf muscles to the heel bone. It causes localized pain and stiffness, often worse in the morning or after long periods of activity. Up to 9% of recreational runners experience this injury each year, making it a common problem in the running community.

The pain usually develops gradually and can limit your ability to run or even walk comfortably. Many people assume that resting the tendon will help it heal, but this approach often leads to longer recovery times and persistent symptoms.

Why Rest Alone Is Not Enough

Tendons respond differently to injury compared to muscles or bones. When a tendon is injured, it needs controlled mechanical stress to stimulate healing and remodeling. Resting completely removes this stimulus, which can cause the tendon tissue to weaken further.

Research shows that tendons require loading to:

• Promote collagen production

• Improve tendon structure

• Increase strength and flexibility

  
  

Without this loading, the tendon can become stiffer and more prone to re-injury. This explains why rest alone often leads to ongoing pain and dysfunction.

The Role of Progressive Loading in Recovery

Progressive loading means gradually increasing the amount of stress placed on the tendon through specific exercises. This approach helps the tendon adapt and heal over time. The most effective method supported by research is the Alfredson heavy slow resistance protocol.

This protocol involves:

• Slow, controlled heel raises

• Using body weight or added resistance

• Performing exercises twice daily for 12 to 16 weeks

  
  

Studies have shown that this type of loading reduces pain and improves function better than rest or other exercise methods. A systematic review by Beyer et al. (2015) found that heavy slow resistance training produced better long-term results than the traditional eccentric-only exercises.

Importance of Biomechanical Assessment

Achilles tendinopathy often results from training errors or biomechanical issues. Common contributing factors include:

• Calf muscle weakness

• Limited ankle dorsiflexion (ability to flex the foot upwards)

• Faulty running gait

• Sudden increases in training load

  
  

A thorough biomechanical assessment can identify these problems. Addressing them through running retraining and corrective exercises helps reduce the risk of recurrence. For example, improving calf strength and ankle mobility can take pressure off the tendon during running.

Additional Supportive Treatments

While progressive loading is the foundation of treatment, some additional therapies can help manage symptoms and support recovery:

• Kinesiology taping: Provides short-term support and reduces tendon load during activity

• Acupuncture and dry needling: Emerging evidence suggests these can reduce pain and help patients tolerate loading exercises, especially in early stages (Minagawa et al., 2013)

  
  

These treatments should be used alongside a structured loading program, not as replacements.

Recovery Timeline and Expectations

Most patients recover fully within 12 to 16 weeks when following a progressive loading program. Surgery is rarely needed unless symptoms persist despite conservative treatment.

Consistency and patience are key. Tendon healing takes time, and pushing too hard too soon can worsen symptoms. Working with a physiotherapist or sports injury specialist ensures exercises are done correctly and progress safely.

Getting Professional Help

If you experience Achilles tendon pain, seek a professional assessment to develop a tailored rehabilitation plan. For those in South Kensington, Ali Momeni Pour at Physiome Kensington, Ethos Sports Centre, Imperial College London offers expert physiotherapy and running assessments focused on Achilles tendinopathy.