"Chronic extreme exercise appears to cause excessive 'wear-and-tear' on the heart, " the editorial says.

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It is also a good idea to wear proper trainers when taking exercise to protect the ankle and knee joints.

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They are also a risk to individual members of the locally dominant group who want to exercise their rights: for example, young women who choose not to wear headscarves or enter arranged marriages.

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It was a catwalk of energetic, giggly models in active wear chatting on cellphones as they waved to attendees, then an exercise routine led by the designer that included running in place, yoga and pull-ups.

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