Pranayama means energy control. It is a grab-bag term that includes methods of meditation, breath regulation, concentration, gazing, and sense-introversion. As such, pranayama has a whole host of applications. In the school of Raja Yoga, pranayama is the advanced technique of stilling the breath, stilling the heart, and withdrawing the mind from the senses.

Pranayama is like any discovery of science. It has been rediscovered countless times and taught cross-culturally. The techniques of pranayama were known to many ancient civilizations. However, since only India has survived the passage of time, pranayama has been given an Indian bent as is referred to with a Sanskrit word.

Pranayama is not different so much as it is the science behind the various techniques used by the mystical, spiritual, and religious systems of the world. The methods taught by the various religions are but variations on the theme of pranayama. However, since these religions formed during darker ages, their techniques are not as sophisticated as formal pranayama. The philosophy behind pranayama as taught by Sankara Saranam is the high age system of Advaita Samkhya.

Developed in India, Yoga is a psycho-physical discipline with roots going back about 5,000 years. Today, most Yoga practices in the West focuses on the physical postures called "asanas," breathing exercises called "pranayama," and meditation. However, there's more to it than that, and the deeper you go the richer and more diverse the tradition becomes. The word "Yoga" means union. Linguistically, it is related to the Old English "yoke." Traditionally, the goal of Yoga is union with the Absolute, known as Brahman, or with Atman, the true self. These days the focus is often on the more down-to-earth benefits of Yoga, including improved physical fitness, mental clarity, greater self-understanding, stress control and general well-being. Spirituality, however, is a strong underlying theme to most practices. The beauty of Yoga is in its versatility, allowing practitioners to focus on the physical, psychological or spiritual, or a combination of all three.

Many. There are four paths of Yoga: 1) Jnana, the path of knowledge or wisdom; 2) Bhakti, the path of devotion; 3) Karma, the path of action; and 4) Raja, the path of self control. Hatha Yoga, which includes postures and breathing, and is the form most popular in the West, is actually part of Raja Yoga, the path of self control. The path most followed in India is thought to be Bhakti Yoga, the path of devotion. Within Hatha Yoga there are many styles, such as Iyengar, Astanga, Integral, Kripalu and Jiva Mukti, to name a few. These Yogas all share a common lineage back to Patanjali's Yoga Sutras, a text outlining the basic philosophy and practices of Classical Yoga. It was written sometime between the second century B.C. and the first century A.D.

No and...maybe. It depends on how you define "religion" and how the Yoga practitioner approaches his or her practice. The physical and psychological benefits of Yoga are real and don't discriminate on the basis of race, religion, gender, political persuasion or any other way people like (or dislike) to categorize themselves. The benefits also don't depend on chanting Om. On the spiritual side, most mystical traditions -- East or West -- draw similar maps of the spiritual path. So in that respect, Yoga is mainstream. Like Shakespeare said, "A rose by any name would smell as sweet." For these reasons, many people feel they can practice Yoga without conflict with their religious beliefs. However, Yoga is connected to the Hindu tradition and draws on many Hindu beliefs -- karma, dharma, reincarnation, Atman, etc

Yes. Western science has been studying Yoga for nearly 50 years, and the evidence shows numerous physical and psychological benefits from Yoga. Interestingly, there seems to be something about Yoga -- vs. exercise and controlled breathing -- that is beneficial. For example, a recent study with heart patients showed that those who followed a stress reduction program that included many Yoga practices did better than patients who exercised or did nothing. Further, preliminary studies in the United States and India suggest that Yoga maybe helpful for specific conditions, such as asthma, epilepsy, anxiety, stress and others.

Yes and...maybe. Aerobic exercise is simply exercise that improves oxygenation of the blood through an increased heart rate and deeper breathing. Yoga can do that, especially those styles such as Astanga and ViniYoga that have a strong focus on the flow of one posture to another.

Yoga is an ancient practice with a written history going back thousands of years. It is not New Age, although various New Age movements have adopted and adapted elements of Yoga. In addition, Yoga and New Age movements share a focus on mind/body development. 

Traditional exercise is goal oriented: How many push ups can I do? Can I touch my toes? I'm going to do 10 more crunches today than I did yesterday. Yoga, by contrast, is a process. The idea is to focus your awareness on what you are doing and how you feel as you perform the postures. In exercise, you fail if you miss your goal. In Yoga, you succeed by trying. There's also a difference on the physical level. Weight training, for example, makes you stronger by breaking down and rebuilding muscle tissue. It's this breaking down and rebuilding that results in the bulky muscle look. Yoga increases strength by toning the muscles.

Any one of the basic styles can be physically challenging. It depends on what you do and how you approach it. Some styles focus on holding postures for a long time, which can be very challenging, while others link a series of postures into a single flow, which results in physical workout. Ashtanga, Bikram's, Iyengar and Power Yoga are probably the most physically focused forms of Yoga.

It's okay to continue practicing Yoga while you are pregnant as long as you were practicing before conception. Yoga is a great way to keep fit during pregnancy. In particular it can help strengthen the pelvic area, normalize thyroid functioning and blood pressure, and help keep you calm and relaxed -- all of which is good for the baby, too. In general, however, you want to avoid strain, compressing the belly or abdomen and inverted postures, especially in the later stages.  It's also a good idea to work with a Yoga teacher with pre-natal Yoga experience.