Maintaining a regular yoga practice has proven to deliver physical and mental benefits. From battling with hypertension, blood sugar to depression, yoga predominantly cures all ailments that can be cured simply with lifestyle changes.
Yoga is not all about flexibility, it is about physical, mental, and spiritual health. Yoga is an effort to harmonize your mind, body, and soul, through asanas, breathing exercises, and meditation.
Yoga dates back to pre-vedic indian times. Maybe during 3000BC, i.e., during the Indus valley civilization. However, in the 3rd century, Yoga was developed as a study.