Tendons lose their elasticity with age, making them vulnerable to irritation and inflammation.
Who Gets It:
Runners, especially older ones. Ramping up the volume or intensity - especially by running up and down hills - can lead to Achilles problems.
Ways to Prevent It:
Stretch your calves. Ask a trainer to teach you how to stretch the soleus, the smaller muscle that runs down the back of your calf.
How to Fix It:
Rest. Use ice and possibly anti-inflammatories.
The Latest Treatment:
Research suggests that "eccentric training" using heavy loads - in this case, certain calf exercises that lengthen the muscles as they are trying to contract - can improve the pain and disability of Achilles tendinitis.