A woman dressed all in black perches on a mat in a wood-panelled room. She is a tiny figure at the centre of this laminate cube; her immaculately waved blonde hair barely moves as she performs a ...

Each day, thousands of women, myself included, engage in a ritual. We flail our arms like orchestra conductors. We wiggle our rib cages. We get down on all fours and raise our knees to our ears. We ...