A double‐blind, randomized, sham‐controlled trial concluded that high‐resistance inspiratory muscle strength training (IMST) improves blood pressure (BP) and endothelial function in midlife/older adults with above‐normal initial systolic BP. Thirty‐six participants of 50–79 years old with systolic BP ≥120 mm Hg were randomized to high‐resistance IMST (75% maximal inspiratory pressure, 30 breaths/day, 6 days/week, n=18) or low‐resistance sham training (15% maximal inspiratory pressure, n=18). While BP was unaffected by sham training, casual systolic BP decreased from 135±2 mm Hg to 126±3 mm Hg with IMST, and ≈75% sustained 6 weeks after IMST, whereas IMST modestly decreased casual diastolic BP (79±2 mm Hg to 77±2 mm Hg). Twenty‐four-hour systolic BP was significantly lower after IMST versus sham training. Brachial artery flow‐mediated dilation improved ≈45% with IMST but was unchanged with sham training. Human umbilical vein endothelial cells cultured with subject serum sampled after versus before IMST exhibited increased NO bioavailability, greater endothelial NO synthase activation, and lower reactive oxygen species bioactivity. IMST decreased C‐reactive protein and altered select circulating metabolites (targeted plasma metabolomics) associated with cardiovascular function. Neither IMST nor sham training changed arterial stiffness. The findings are in line with previous studies, and deep breathing with low resistance has been reported to have sustained systolic BP‐lowering effects as well, though with a much greater time requirement (≈30 min/d) than high‐resistance IMST. In addition to lowering BP, studies have shown that structured deep breathing programs can be beneficial for anxiety, pain, blood glucose, lung diseases and sleep apnea. Source: https://www.ahajournals.org/
