Brahmacharya means, “restraint, control over all senses and especially over the sexual energy.”
This control involves transmutation of the sexual potential (sperm in man’s case and sexual fluids in woman’s case) into erotic energy and leading this energy to the superior levels of the being.
The control over the sexual energy has to be done both when you have renounced definitely or even temporary at your sexual activity and when you have an intense sexual activity (practiced with sexual continence).
Brahmacharyasana is a position that aids the transmutation of the sexual potential into energy leading it to the superior levels of your being. This position also involves the power of focusing and stimulates the mental control. It allows us to easily reach a state of mental focus doubled by a lucid attention.