How to do it-
From Tadasana, step your right leg a meter behind you and bring your feet parallel (facing the right side of your mat).
Turn your right foot 90 degrees to the right, so it is facing the back of the mat.
Turn your left foot 45-60 degrees to the right (so that your left toes are also facing towards the back of your mat).
Align your right heel and your left heel, or if it helps you to balance, the left heel can be slightly over to the left (just not more over to the right that the right heel or you will loose stability)
Square your hips, ensuring that they are pointing towards the back of the mat (sometimes its good to hold your hips and square them, and adjust your feet again so that your hips can stay in the correct position)
Bring your hands behind your back, and either clasp hold of your elbows with opposite hands, or if you can, bring your hands into Anjali Mudra (reverse namaste).
As you inhale, lengthen the spine and open the chest, looking up slightly.
As you exhale, fold your torso over your front leg.
Stay in intense side stretch pose for 5 long and deep breaths, trying to keep your spine straight. Use your breath to relax you further into the posture, don’t force your body down.
Benefits-
Intense side stretch pose strengthens the legs.
Stimulates the internal organs.
Improves posture.
Encourages the chest to open.
Stretches the spine and shoulders, hips and hamstrings.
Improves sense of balance.
Calms and relaxes the brain.
Contraindications
If you have high blood pressure, or a back injury, avoid coming into a full forward bend in this posture.