Are you weary of cookie-cutter fitness plans devoid of anything you can actually use? Or programs promising great abs by Monday?

Eric Heiden, M.D., and Massimo Testa, M.D., are renowned physicians who've spent their lives facing every conceivable exercise problem, helping both elite athletes and people who want to finish a 5K or achieve lower blood pressure.

Part I of this book is a treasure trove filled with everything everyone should know about fitness but that even the best athletes do not, including how to start (or restart) an exercise regimen; eat before, during, and...