Achilles tendon injuries are common in runners. The aim of the present study was to analyse the training programme, any Achilles tendon problems, muscle tightness and range of motion of the ankle joint, and concentric and eccentric muscle torques of the calf muscles in middle-distance runners with and without Achilles tendon problems. Eighty-three middle-distance runners answered a questionnaire on their sports background, training habits and any injuries. Thirty-four percent had suffered from some type of problem relating to the Achilles tendon. Ten of the athletes who had suffered from Achilles tendon problems and ten who had never had any Achilles tendon trouble were randomly selected. These 20 runners underwent a clinical examination. The range of motion of the ankle joint was recorded objectively by a hydraulic and computerised isokinetic dynamometer by measuring resistance to passive motion. Concentric and eccentric muscle torques of the gastrocnemius-soleus complex were recorded. The runners with Achilles tendon problems had trained for significantly more years and covered significantly longer distances per week than runners without Achilles tendon problems. There were no significant differences in other training methods or in best results over 800 m and 1500 m. Runners with Achilles tendon problems had a significantly lower range of motion of the ankle joint. They also had significantly lower eccentric torques of the gastrocnemius-soleus complex, but no differences in concentric torques were found between the groups.