Book excerpt: Scientists are proving what Tibetan monks knew all along: there are real benefits to the pursuit of mindfulness. The practice of meditation, which includes living in the moment and being in touch with your emotions, can change your body and brain, keeping them fit, flexible and resilient as you age. TIME's special edition offers: * Mindfulness tips for everyone, from the novice to the lifetime meditator* The latest research on mindfulness, heart health and sleep* How to bring mindfulness into your day without having to sit still on a cushion.