Ever wondered what keeps Supreme Court Justice and octogenarian Ruth Bader Ginsburg so sprightly? She owes it in part to workouts with personal trainer Bryant Johnson, someone she's called "the most important person" in her life. Johnson's book "The RBG Workout: How She Stays Strong . . . and You Can Too!" teaches you how to do Justice Ginsburg's workout -- from planks to squats. He'll discuss the book with Politico's Isaac Dovere at D.C.'s Sixth & I.