Timothy McCall, M.D. is a board-certified internist and the Medical Editor of Yoga Journal. A Yoga practitioner from 1995, Dr. McCall travels regularly to India to research yoga, yoga therapy and Ayurveda, and to study with a traditional Ayurvedic Vaidhya (doctor) in Kerala and a Tantric master in Bangalore. His main focus since the year 2000 has been investigating the therapeutic aspects of yoga, as well as the scientific explanations of yogas effects. Dr. McCall lectures internationally and is the author of Yoga as Medicine: The Yogic Prescription for Health and Healing and Examining Your Doctor: A Patients Guide to Avoiding Harmful Medical Care.