Hamstring and Spinal Stretch

This is an intense stretch of the hamstrings and back. Only go as far as you can when stretching, never over-stretch or over-strain. Yoga is not a competition and if you don't take care and approach each stretch with concentration, attention and without ego you can injure yourself. Whether you are in a class or practising at home alone you should approach each asana (posture) in the same way: as well as you can on any given day. Some days you'll have better stretching days than others, in the same way you have better running or cycling sessions.
Begin by standing with the feet parallel and just a little apart near the back of your practise mat:

• imagine you are standing on a clock. Turn the right foot so the toes point at 1 o'clock then take a large step forwards with your left leg keeping the left foot at 12 o'clock
• align your hips straight ahead
• inhale and raise both arms above your head
• exhale and bend forwards from the waist, keep the chest and head lifted looking ahead of you, this keeps the back flat
• when you can't bend forwards anymore with a flat back relax the chest and head towards the leg, relax the arms towards the floor and if your hands reach the floor just relax them without placing your weight on them
• if you cannot stretch down very far, that's fine. Just relax your hands and arms either side of your legs
• breathe slowly and deeply and try to consciously relax the muscles in the legs, buttocks, back and shoulders
• take 5 long slow breaths before lifting the head, shoulders and chest to make a flat back and come to standing on an in-breath
• bring both feet together and stand straight for a few moments before doing the posture with the right leg forwards

The key to this posture is deep, slow breathing and not rushing. It takes around 30 seconds for a muscle to start relaxing in a stretch so take your time. If at any time you feel pain, or your legs shake, then slowly come out of the posture and next time don't try to push yourself so hard.