Eventually the pain is fairly regular and progresses to the point that any exercise or activity is painful and avoided. The biggest contributor to chronic Achilles tendonitis is ignoring early discomfort and exercising anyway. If the Achilles tendon is sore, or aches, you need to pay attention and rest it now. Another major contributor in the development of Achilles tendonitis is tight of weak calf muscles. If this muscle is weak and becomes fatigued, it will tighten and shorten.
Overuse also causes muscle fatigue.
This tightness will increase the stress on the Achilles tendon, and a tendonitis can develop. Sudden increases in training, hill running or a lot of speedwork can also lead to Achilles tendonitis. At the first sign of Achilles tendon pain, cut back and reduce your training. Cut out on any speed or hill work, and begin gentle calf stretching after exercise when the muscle and tendon is still warm and flexible. Post running ice may also help.