Nestor, James. Breath: The New Science of a Lost Art. Riverhead Books, 2020.
Perhaps Iga Swiatek was inspired by the above title by James Nestor. In this book he makes a compelling argument regarding the transformation of human breathing techniques brought about by a changing mouth and throat structure. Through various sources he studies the changes that are occurring possibly due to foods progressively becoming softer allowing the jaw muscles to become weaker and the tongue moving deeper into the throat. He claims sleep apnea and asthma, and a few other breathing issues are recent developments and are results of this evolution.
After reading the book I slept for four weeks with a strip of tape holding my mouth shut. At the end of my non-scientific study, I did feel a more open nasal cavity but had no significant change in daily running pace.