Generally, the word yoga refers to an integration of physical and mental exercises designed to balance and unite the mind, body, and spirit. Various branches of yoga emphasize a particular approach to this integration. Jnana Yoga takes the path of knowledge or wisdom; Bhakti Yoga is the path of devotion; Karma Yoga is the path of action or service; Tantra Yoga is the path of ritual; Raja Yoga is the path of meditation; Hatha Yoga is the path of physical postures (called asanas) and breathing (pranayama).

In the West, when we use the word yoga, we most often are referring to Hatha Yoga.

Benefits of Hatha Yoga
The postures and breathing techniques of Hatha Yoga yield many benefits to the practitioner's health and well-being. Hatha Yoga promotes flexibility, tones the body, enhances vitality, cultivates balance, and calms the mind. It improves strength and endurance and increases awareness and concentration. It alleviates stress and creates a welcome feeling of wholeness and deep relaxation.

Styles of Hatha Yoga
There are many schools of Hatha Yoga, and many approaches to teaching. It is not unusual for teachers themselves to study in various schools and to blend techniques to create their own approaches. Differences among the schools are usually about emphasis: One may focus on strict alignment of the body, another on coordination of breath and movement; one may focus on holding each posture for a period of time, another on the flow (vinyasa) from one posture to another. A new yoga student may want to try classes in different styles and with different teachers to find those that best match his or her needs.

Many of the schools of Hatha Yoga popular today in the West can trace their roots to the Indian Sanskrit scholar and teacher Krishnamacharya (1888-1989), several of whose pupils have themselves become prominent teachers. Among the most popular and influential in the West are: B.K.S. Iyengar, who founded Iyengar yoga; T.K.V. Desikachar (Krishnamacharya's son), who carries on the tradition, known as Viniyoga, that he learned from his father; and Sri K. Pattabhi Jois, who developed Ashtanga Yoga. There are, however, many popular schools of yoga that may be most suitable for the beginner student. We have provided a comprehensive list of yoga styles and approaches to help you find what you are looking for.

Ananda Yoga
Ananda Yoga is a classical style of gentle Hatha Yoga that uses breathing and postures accompanied by silent, positive affirmations to awaken, experience, and begin to control the subtle energies within us. Its object is to use those energies to harmonize body, mind, and emotions, and to expand self-awareness. Ananda yoga is a relatively gentle, inward experience, not an athletic or aerobic practice. It was developed by Swami Kriyananda, a direct disciple of Paramahansa Yogananda, author of the spiritual classic, Autobiography of a Yogi.

Anusara Yoga
Anusara (a-nu-SAR-a) means "following your heart," or "to move with the current of divine will." It is a style of yoga developed by John Friend, whose main Hatha influence was B.K.S. Iyengar. Anusara Yoga is described as heart-oriented, spiritually inspiring, yet grounded in a deep knowledge of outer- and inner-body alignment. Each student's various abilities and limitations are deeply respected and honored.

Ashtanga Yoga
Ashtanga Yoga (often also called Power Yoga) was first developed by Sri K. Pattabhi Jois and is an aerobic, muscle-shaping, mind-sculpting, physically demanding workout. Students move through a series of flows, moving from one posture to another to build strength, flexibility, and stamina. Room temperatures are often set high to promote detoxification through increased perspiration. Ashtanga often appeals to athletes and those who enjoy high-energy exercise.

Bikram Yoga
Bikram Choudhury's yoga is hot, hot, hot, so be prepared to sweat, sweat, sweat. In class, they crank the thermostat up high, and then perform a series of 26 asanas (each held for at least 10 seconds) and two pranayamas, sometimes twice. The series is designed to warm and stretch muscles, ligaments, and tendons in a naturally progressive order. Founder Bikram Choudhury studied yoga with Bishnu Ghosh, brother of Paramahansa Yogananda, author of the spiritual classic, Autobiography of a Yogi.

Body-Mind Centering® Yoga
Body-Mind Centering® Yoga combines the activities of Body-Mind Centering and yoga poses through the conscious embodiment of the student's cells, tissues, body systems, and developmental patterns. Proponents of Body-Mind Centering believe that when students initiate poses in this embodied way, they execute each pose as an expression of his or her present state of being. A student's yoga experience is then shaped by the fullness of his or her cellular involvement rather than dictated by the ability to complete an external form. Static positions transform into dynamic patterns of movement as students, as well as their practice, become enlivened.

Integral Yoga
Integral classes put almost as much emphasis on breathing and meditation as they do on postures. Classes begin with 45 minutes of postures, followed by deep relaxation, a breathing sequence, and a meditation. Swami Satchidananda, who led the crowds at the original Woodstock festival in an opening chant of "Om," developed Integral Yoga. It is the style used by Dr. Dean Ornish in his groundbreaking work on reversing heart disease.

ISHTA Yoga
ISHTA—Integrated Science of Hatha, Tantra, and Ayurveda— is a joyful, beginner-friendly mix of 15 kinds of yoga, including athletic Ashtanga, flowing Viniyoga, and precise Iyengar, combined with Tantric meditation techniques and ayurvedic practices to rebalance one's life. Developed by Alan Finger and his father Kavi Yogiraj Mani Finger, it is a tradition with roots in teachings by Paramahansa Yogananda, author of the spiritual classic, Autobiography of a Yogi.

Iyengar Yoga
Iyengar yoga emphasizes posture and the development of balance and alignment. To support students' explorations of postures, Iyengar yoga makes use of a wide variety of props: belts, blocks, pillows, and balls. Iyengar is one of the most widely practiced yoga techniques in the West. It was developed in India by B.K.S. Iyengar and responds to individuals with varying limitations and capacities for accomplishing postures. Iyengar Yoga is noted for great attention to detail and the precise alignment of postures.

Jivamukti Yoga
Jivamukti, a Sanskrit word that means "liberation while living," was developed by Sharon Gannon and David Life and combines a vigorous physical practice with an equally strong foundation in ancient spiritual traditions of yoga. Each class focuses on a theme, which is supported by Sanskrit chanting, readings, references to scriptural texts, music (from the Beatles to Moby), spoken word, asana sequencing, and yogic breathing practices.

Kali Ray TriYoga
Kali Ray TriYoga, founded by Kali Ray, brings posture, breath, and focus together to create dynamic and intuitive flows. These flows combine active and sustained postures that emphasize wavelike movements of the spine, economy of motion, and synchronization with breath and gestures. The flows are systematized by level and can be as gentle or as challenging as desired. Students may progress from basics to advanced as they increase their flexibility, strength, endurance, and knowledge of the flows.

Kripalu Yoga
Kripalu Yoga puts great emphasis on the mechanics of yoga—proper breath and alignment—as well as on the inner, spiritual dimensions of yoga practice. Students are encouraged to honor "the wisdom of the body" and to work according to the limits of their individual flexibility and strength. There are three stages in Kripalu yoga. Stage one focuses on learning the postures and exploring your body's abilities. Stage two involves holding the postures for an extended time, developing concentration and inner awareness. Stage three is called "Meditation in Motion," in which movement from one posture to another arises unconsciously and spontaneously. Kripalu yoga was developed by Yogi Amrit Desai, who was inspired by his guru, Swami Kripalvanandaji, a Kundalini Yoga master from India.

Kundalini Yoga
Kundalini Yoga in the tradition of Yogi Bhajan, who brought the style to the West in 1969, focuses on the controlled release of kundalini energy, thought to reside at the base of the spine. This style of yoga pays particular attention to breathwork, which aims to get energy moving quickly, but it also involves classic poses, coordination of breath and movement, and meditation.

Natural Yoga
The focus of Natural Yoga, developed by Dinabandhu and Ila Sarley, is to learn to use the practice of yoga not only as a physical discipline to tone the body and calm the mind, but also as a personal spiritual practice. Natural Yoga is the practice of awakening, attuning to, and being guided by the natural intelligence or life force within us. Yoga's true aim is to connect us with our deeper integrated self, starting by fully being in one's body. In the Natural Yoga practice, students build a foundation for developing a daily yoga practice by understanding the three primary principles of yoga: skillfulness in action, equilibrium, and absorption. Through a powerful and engaging flow of postures, students learn the fundamentals of alignment in Hatha Yoga and then use meditative movement, rhythmic breathing, and one-pointed focus to engage in a mystical and healing journey that moves through the peak intensity of the yoga postures into a profound sense of stillness.

Partner Yoga
Partner Yoga is an interactive yoga practice in which the students may be long-term committed partners or newly met attendees at a partner yoga workshop. Asanas in partner yoga are generally familiar yoga postures performed, perhaps with adaptations, together by two people. Partners may differ in size, shape, strength, flexibility, and experience. Partner Yoga emphasizes building trust in and sensitivity to relationship while exploring the balance, centeredness, and healing qualities of yoga practice.

Power Yoga
Power Yoga combines the ancient "eight limbs" of yogic wisdom revealing a systematic set of proven age-old principles, physical practices, attitudes, and perspectives. Power Yoga uncovers the root causes of stress and provides the means to conquer it, demonstrates the value of exercise and attitude, and harnesses the power of discipline and inner balance. It is a muscle-shaping, mind-sculpting workout that crosses all borders and appeals to any person who has the desire for true and permanent change in his or her body and life.

Restorative Yoga
This is a gentle, calming, therapeutic kind of yoga that uses props to support the body to deepen the benefits of the poses. It is a soothing and nurturing practice that promotes the effects of conscious relaxation.

Sivananda Yoga
Sivananda, one of the world's largest schools of yoga, is very supportive to beginners. Developed by Swami Vishnu-Devananda and named for his teacher, Swami Sivananda, Sivananda Yoga follows a set structure that includes breathing, classic asanas, and relaxation, as well as principles of diet and positive thinking. The Complete Illustrated Book of Yoga, written by Swami Vishnu-Devananda and first published in 1960, was one of the first, and continues to be one of the best, introductions to yoga available.

Svaroopa Yoga
Svaroopa is not an athletic endeavor, but a development of consciousness using the body as a tool. Developed by Rama Berch, Svaroopa Yoga teaches significantly different ways of doing familiar poses; it emphasizes opening the spine by beginning at the base of the spine and progressing through each spinal area in turn. Each pose integrates the foundational principles of asana, anatomy, and yoga philosophy, and develops the transcendent inner experience, called svaroopa. This is a consciousness-oriented yoga that also promotes healing and transformation.

Viniyoga Yoga
Viniyoga is not so much a name of a yoga style as it is a methodology for developing a personal practice using asanas, pranayama, meditation, ritual, and prayer. Viniyoga, which was developed by Krishnamacharya and is carried on by his son, T.K.V. Desikachar, respects individual needs and capabilities. Key characteristics of the asana practice are the careful integration of the flow of breath with movement of the spine and thoughtful sequencing of asanas. Function is stressed over form.

What is the most physically challenging form of yoga?
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 a physical workout. Ashtanga, Bikram, Iyengar, and Power Yoga are probably the most physically focused forms of yoga. Kripalu and Integral Yoga are gentler.

source: Omega Institute