Yoga has many benefits that can be summed in 3: physical, therapeutic and spiritual.
The physical benefits are the first to come, for they come after any physical effort: they are the same of aerobics or running: more strength and flexibility.
The practice of Hatha Yoga can cure several diseases, and many doctors recommend it to help the muscles heal from injuries.
It also soothes the mind and helps with depression and anxiety among other affections. Those are the therapeutic benefits.
But the most important benefit is the spiritual one. Any exercise can increase your stamina, strength and flexibility and many medicines can cure diseases. But the union of body and mind is the one goal that can only be reached through Yoga, no matter what type you practice.
Who am I? - Mani Raman
Lecture on 4 dimensions - Mani Raman
The length of a class
About the importance of breathing
The benefits of Yoga
How to leave the pain behind
What is Love?
Focus your mind during the practice
Mani Raman - Vedanta Part 1
Is Ashtanga Yoga for everyone?