@margottaylor I think abdominal breathing is also called diaphragmatic breathing. Here's some information on how to do it:
https://my.clevelandclinic.org/health/articles/9445-diaphragmatic-breathinghragmatic

@margottaylor Diaphragmatic breathing, or deep breathing, is breathing that is done by contracting the diaphragm, a muscle located horizontally between the thoracic cavity and abdominal cavity. Air enters the lungs, the chest does not rise and the belly expands during this type of breathing.