Asana

Adho Mukha Svanasana (Downward facing dog)

In this pose you are meant to resemble a dog stretching :)

Lie on your belly with legs hip distance apart and toes tucked under towards your body.
Place your hands by your chest with palm of hand and fingers pressing well into the mat.
Pressing into your hands and feet, bend your knees and lift your hips and buttocks up towards the ceiling.
As you exhale, straighten your arms and legs and lift the buttocks up more to make an upsidedown V shape with the body.
Hold the pose for some breaths (maintaining calm, even inhalation and exhalation).
Then bend the knees and come to lying down once more.

Benefits:  This asana aligns the spine, lengthens the hamstrings, builds muscle strength in the legs and upper body.
Iyengar advises to hold this pose for longer if you're feeling exhausted ~ its particularly good for runners after a long race :)