Osc+ Group
Participants wore an infrared pulse plethysmographDuring the second lab visit, we introduced participants to the device and had them complete five minutes of rest followed by 5-min paced breathing segments at 9 s, 10 s, 11 s, 12 s, and 13 s per breath, which approximately correspond with the 6.5, 6, 5.5, 5 and 4.5 breaths/min paces in Lehrer During the subsequent weekly visits, the participants completed a 5-min rest segment followed by paced breathing segments to calibrate the best resonance frequency