From wrecking your workouts to sabotaging your sleep, stress can wreak havoc on your life. But it can also be energizing, motivating and life changing — if you embrace it. That’s the theory behind a new book called “The Upside of Stress: Why Stress Is Good for You and How to Get Good At It,” by Kelly McGonigal, PhD, a lecturer at Stanford University. Based on a course McGonigal teaches called the New Science of Stress, the book offers loads of stress-related research, along with mental exercises and personal stories to present a compelling argument that stress may not be so bad. “It’s about seeing stress as a challenge rather than a threat,” McGonigal says.