I also find intentional breathing helpful: 8 in, hold for 4, breathe out for 8. Still having a feeling of tightness in my lungs. I have a ground glass nodule along with some that are not ground glass. I did have covid in Feb 2022, but just noticing the tight breathing again over the springtime. My last PFT was not perfect and the Dr wants to run another one. I will probably get one in the fall before returning to the pulmonologist in the winter. I am just being followed, but that first round of tests was unnerving. I am starting short stints of yard work, bending over , which may help.