What are the types of yoga?
There are dozens of types, or schools, of yoga. They evolved over the centuries as different yogis developed their own philosophies and approaches and taught them to eager students, who then passed them on to their own students and disciples. For instance, Hatha yoga, arguably the most popular type of yoga taught in the U.S., was developed by Yogi Swatmarama in India in the 15th century and described by Swatmarama as (1) "a stairway to the heights of Raja yoga (Raja being one of the six orthodox schools of Hindu philosophy, outlined by Patanjali in his Yoga Sutras) and (2) a preparatory stage of physical purification that renders the body fit for the practice of higher meditation." Likewise, Kundalini yoga, which is reported to be more than 5,000 years old, was introduced to the west in 1969 by Yogi Bhajan when he traveled here from India.
Fundamentally, all yoga types strive for the same outcome, a unification of mind and body and spirit, although they may differ in their philosophy and even in the asanas. For instance, I took a yoga class yesterday that the teacher calledAnusara, which she described as "opening the heart." I have never taken this type of yoga class, but the asanas were familiar (with just slight variations), the savasana at the end of the class was the same as other classes, and I left feeling the same as I do when I take Hatha or any other; that is, I felt calm, relaxed, stronger, and virtuous for having done it.
I did a quick search for yoga types and compiled the following list (certainly not all-inclusive): Purna, Ashtanga, Jnana, Bhakti, Bikram, Karma, Raja, Hatha, Kundalini, Mantra, Tantra, Iyengar, Astanga, Vini, Ananda, Anusara, Integral, Kali Ray Tri, Kripalu, Kundalini, and Sivananda. There's also yoga on the physioball (truly an American invention), and I even found nude yoga! Some of the most popular in the U.S., and the ones you are most likely to find in yoga and fitness centers, are Hatha, Iyengar, Astanga (or Ashtanga), Bikram, and Kundalini. Your local center may teach other types, and so you should contact the center if you are curious. I will briefly describe the most popular types of yoga in the U.S. Many of the others are searchable online.
Hatha yoga is the most widely practiced type in the U.S. and is excellent for beginners. It is gentle with slow and smooth movements, and the focus is on holding the poses and integrating your breathing into the movement. It's a great introduction to yoga as it incorporates many different asanas, as well as pranayamas and chanting. Hatha yoga will prepare you for other yoga types that might be taught at your yoga center. Hatha is a great way to stretch, work your muscles, get in touch with your body, relax, and decrease stress.
Iyengar yoga is a form of yoga that uses poses similar to Hatha, but it focuses more on body alignment and balance, holding poses longer, and using props such as straps, blankets, and blocks. It's also a good choice for beginners.
Kundalini yoga emphasizes rapid movement through the poses and emphasizes breathing, chanting, and meditation. It has a more spiritual feel than Hatha and focuses on energy balance in your body. You might find Kundalini physically and mentally challenging if you're a beginner and unfamiliar with yoga poses, chanting, and meditation, and so Hatha or any beginner class is probably a better way to go.
Bikram yoga is derived from traditional Hatha yoga, but is practiced in a room (sometimes unventilated) heated to about 105 degrees Fahrenheit. The objective is to loosen muscles and to sweat to cleanse the body and remove symptoms of disease and chronic pain. To my knowledge, there hasn't been any research on the safety or efficacy of Bikram, and so I don't recommend it because of the potential risk of dehydration, hyperthermia (overheating), blood pressure changes, and cardiac problems with exertion in such an inhospitable environment. This is particularly so for individuals who may have an existing heart problem or high blood pressure but don't know it. Bikram has grown in popularity, and some people swear by it. I recommend that you speak with your physician first if you are determined to try it.
Ashtanga yoga, or power yoga, is an ancient system of yoga taught by Sri K. Pattabhi Jois at the Ashtanga Yoga Research Institute in Mysore, India. In the U.S., it is taught as an aggressive workout where you move quickly from one pose to another to build strength and endurance. There is little emphasis on meditation with Ashtanga, and at the end of the session you will feel more like you have completed a traditional weight-training or callisthenic workout than you would with any other type of yoga. Ashtanga is for you if you're looking for a tough, physically challenging workout.
Like I said, there are many other yoga types, and you can find information about all of them online.