Fists closed and thumbs extended, close your eyes, breathe in through your mouth in the shape of an O, as slowly as possible in 20 seconds (15 or 10 seconds depending on your ability), hold the breath for 20 seconds, then breathe out through your nose in 20 seconds.

Concentrate on the flow of the breath.

At the end, apply the closes: inhale, hold the breath, pull in the belly, stretch the arms and spread the fingers. Stretch as much as you can by sticking your belly with your spine and then exhale through your mouth like a cannon. Repeat this 3 times.