Aimee Hartley, like most people, thought she knew how to breathe – she had, after all, been doing it all her life. She had also given it plenty of thought, having trained as a yoga teacher. But then she took a lesson with a breathing coach, who told her where she was going wrong. He pointed out she wasn’t taking the air into her lower lungs but was, she says, an “upper chest breather. He then taught me this conscious breathing and I felt my lower belly open, and I felt myself breathing a lot better after just one session. So I then became fascinated by how we breathe.”