Why It’s So Much Harder To Train at Higher Altitudes If You’re Not Used to It

What is altitude training? One runner who moves to Aspen, tries out the training plan to see how it works for her. Here's what to know.

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<a href="http://www.stocksy.com" target="_blank" rel="noopener noreferrer">/Javier Diaz

Adult Ballet is on the Rise—And Yes, You Should Totally Try it

Here's what to know before your first class.