All that is required for success in yoga is cheerfulness, perseverance, courage, correct knowledge of the techniques to be followed, moderation in one's habits, and faith in the practice of yoga. Then the effects of yogic practice as enumerated by the sages follow. These are beauty and strength, clarity of speech and expression, calmness of the nerves, an increase in one's digestive power, and a happy disposition that is revealed in a face full of smiles.