How a woman whose muscles disappeared discovered she shared a disease with a muscle-bound Olympic medalist.

How agents took down Mexico’s most vicious drug cartel and, in the process, gave El Chapo the opportunity to create an empire.

Alberto Salazar is one of the most celebrated running coaches in the world. Is he also a cheater?

An interview on nature vs. nurture with the author of The Sports Gene: Inside the Science Of Extraordinary Athletic Performance.