The First Century editor of the Yogasutras named Patanjali wrote that "Yoga is the ability to direct the mind exclusively towards an object and sustain that direction without any distractions." The intention is that by directing the mind and perceiving clearly, we will make better decisions and thereby reduce both our own suffering and the suffering in the world.
Yogis on the Indian subcontinent
found that they needed to feel well to be able to maintain their concentration.
They developed a science of movement, called asana (aah-sa-na), that is
one of eight parts of yogic studies.