Yoga as Exercise is Yoga done as a pure physical activity for fitness and health benefits, that is, rather as gymnastics, more or less disregarding its traditional Indian spiritual aspects.
In the past decades, Yoga as Exercise has become specifically popular in the United States and Europe, although it’s perhaps now the most common type of Yoga around the globe. Yoga as Exercise is also known as Postural Yoga, Anglophone Yoga, and Gymnastics Yoga, among some other labels.
Yoga as Exercise is derived from Hatha Yoga, and the main focus of the practice consists of performing Yoga Asanas (the Yoga poses done either statically or more dynamically), breathing exercises, some meditation, and finally relaxation exercises.
Historically, Yoga Asanas were of less importance for Yogic practices, but within Yoga as Exercise (growing in popularity as from the beginning of the 20th century) they started to get a prominent place. The main reason to this was that Asanas were increasingly seen as having both physical and mental health benefits.
One of the leading figures of popularizing Yoga as Exercise (period 1930s – 1950s) was the Yoga teacher Krishnamacharya who’s considered the “Father of Vinyasa Yoga.” Two famous disciples further developed his style of practicing Yoga: Pattabhi Jois (Ashtanga Vinyasa Yoga) and Iyengar (Iyengar Yoga). Both Yoga teachers became rather famous, globally, and profoundly contributed to the further spreading of Yoga as Exercise.
From that point on a vast range of “new” Yoga modalities were created, such as Bikram Yoga (or Hot Yoga), Power Yoga, Restorative Yoga, Anusara Yoga, and Sivananda Yoga, to name some well-known styles.