'Armed with the information in this book, readers will be inspired and motivated to reassess their habitual exercise programs and make positive changes.' Publisher's Weekly 'This is a science book, first and foremost ... you will learn about the current state of physiology, biology, psychology, and the neurology of couch potatoes and of athletes and everyone in between. What's cool is how much we now know, and how much we used to "know" was wrong. The big takeaway is that a little exercise is enormously better than none. And fidgeting is good.' - John Goodreads 'Whether directed at a marathoner or a once-a-week sprinter, Reynolds' important message rings true: "The body wants to move," she writes. "Go with it."... Solid advice with motivational oomph to get you up and running.' Kirkus Review 'Smart, clear, and beautifully useful, this is the new fitness bible for the modern age.' - Dan Coyle, author of The Talent Code

Gretchen Reynolds writes for the popular 'Phys ED' column in The New York Times. She also writes for The New York Times Magazine, O: The Oprah Magazine, Men's Journal, Outside, Parade, Popular Science and others.