Mary Roach's previous books include Fuzz: When Nature Breaks the Law and Stiff: The Curious Lives of Human Cadavers. Jen...
NPR
There's a growing consensus among researchers on how many daily steps are needed to improve health. Marco VDM/iStockphoto/Getty Images hide...
:max_bytes(150000):strip_icc()/Health-GettyImages-1413749294-1e0959850fd24395b36963b6b3f2e109.jpg "What Happens to Your Muscles When You Take Amino Acid Supplements?")
