The use of eccentric resistance training as management of Achilles tendinopathy is widespread. The investigators have recently demonstrated that heavy slow resistance training was superior in the management of patellar tendinopathy.

Hypothesis: heavy slow resistance training is more effective than eccentric resistance training in the clinical management of Achilles tendinopathy.

Inclusion Criteria:

• Unilateral Achilles tendon pain,
• Symptoms for at least three months,
• Ultrasonographical tendon abnormalities, AND
• Able to comply with both intervention arms.

Exclusion Criteria:

• Bilateral symptoms,
• Previous surgery below knee,
• Corticosteroid injections below the knee during past year,
• Hypercholesterol,
• Diabetes, OR
• Arthritis.