What makes yoga an important part of a workout plan?

[Cicero]

Also, how many times a week do you have to do yoga in order to see a big difference in flexibility? How does yoga make you more stretchable? What does yoga do to your body?

[CanadaRocksEH]

you can do it once per week and you will see gains after a bit, with stretching u get little micro tears in ur muscle and when they heal they are longer and able to stretch more/farther, yoga helps with the mind and body, relaxes you, increases your flexibility, and also helps keep in body in alignment. aka ur spine