Book excerpt: The Inner Gym provides you with a series of "inner exercises" that will do for your happiness what outer exercises like pull-ups, push-ups and squats do for your physical muscles.These exercises will help to build and strengthen your happiness. After all, true happiness is a byproduct of inner strength training.The idea is simple: Each chapter provides you with instructions on how to perform an inner exercise--such as meditation, expressing gratitude, or performing a random act of kindness. There's a log at the end of each chapter for holding yourself accountable. The entire program is only 30 days.Click the play button above to watch the Inner Gym trailer with author Light Watkins.It's the closest thing you can get to a magic bullet for happiness. Start inner exercising today and pump up your inner happiness muscles, and watch how your happiness grows from the inside-out.