At its most basic, yoga is a set of spiritual practices originating in ancient India. While most people in the Western world think of it as a form of physical exercise, it actually encompasses much more. Even only considering the physical side, however, there are many different styles, from traditional to Bikram.
The Bhagavad Gita, a text dating from the first few centuries BCE that's considered the definitive source of Hindu philosophy, mentions four branches of yoga: karma, jnana, raja, and bhakti. Karma refers to one's action in the world, jnana is the development of knowledge and the mind, bhakti is the worship of a deity, and raja is meditation. The style most familiar to those in the Western world, consisting of the practice of asanas or poses in order to reach a meditative state, is a medieval development of the Raja practice known as Hatha yoga.
The most common styles of this practice are:
- Vinyasa links breath to movement and consists of a flowing series of poses using the practitioner's natural breath as a guide. Movement is continuous and the focus is on aligning movement with breath rather than on perfecting each posture. The sun salutation is one well known vinyasa series.
- Ashtanga, or power yoga is fast-paced and physically challenging. Like vinyasa, it is performed in a flowing style, with attention given as much to transitioning gracefully between poses as to the poses themselves.
- Kudalini yoga is practiced with the goal of awakening energy stored in the pelvic area. While asanas are involved in kundalini, the focus is more on breath and chanting. When kundalini energy is released, it is said to flow upward along the spine through energy centers called chakras.
- Iyengar yoga is named after its creator, B. K. S. Iyengar. The focus of this style is proper physical alignment, and poses are often held for long periods of time in order to perfect one's posture. Props, such as straps or bricks are commonly used in this style, as they can be used to help the practitioner reach and maintain correct alignment.
- Bikram yoga is also named after its pioneer, Bikram Choudhury. This style is practiced in a heated room in order to allow the body to stretch and relax more. It uses a series of 26 asanas, always performed in the same order and intended to open the body up gradually throughout the practice. Hot yoga is also practiced in a heated room, but the postures may vary from the Bikram method.