Department of Physiology University of Arizona College of Medicine, Tucson, Arizona.
J Appl Physiol (1985). 2021 Apr 1;130(4):1114-1121. doi: 10.1152/japplphysiol.01015.2020. Epub 2021 Feb 18.
High intensity, low volume inspiratory muscle strength training (IMST) has favorable effects on casual systolic blood pressure and systemic vascular resistance. However, the acute effects of IMST on heart rate (HR), blood pressure (BP), and sympathetic regulation of vascular resistance and the trajectory of post exercise recovery are not known. We recruited 14 young adults (7 women/7 men, age: 22 ± 2 years) to perform a single bout of high intensity IMST (inspiratory resistance set at 75% of maximal inspiratory pressure) importantly, female and male subjects were matched in regard to the target inspiratory pressure and target inspiratory muscle work per breath. We recorded HR, beat-to-beat changes in BP and postganglionic, muscle sympathetic nerve activities (MSNA) continuously throughout baseline, a single bout of IMST (comprising five sets of 6 inspiratory efforts) and in recovery. We show that one bout of IMST does not effect a change in BP, however, it effects a significant increase in HR (68.4 ± 11.7 beats/min versus 85.4 ± 13.6 beats/min; < 0.001) and a significant decline in MSNA (6.8 ± 1.1 bursts/15 s bin; < 0.001 versus 3.6 ± 0.6 bursts/15 s bin) relative to baseline. Remarkably, among men MSNA rebounded to baseline levels within the first minute of recovery, however, in women, MSNA suppression persisted for 5 min. We show that in healthy young adults, high intensity, low volume respiratory training results in the acute suppression of MSNA. Importantly, MSNA suppression is of greater magnitude and longer duration in women than in men. Previous studies show 6 weeks of high intensity, low volume inspiratory muscle strength training (IMST) lowers blood pressure (BP) and systemic vascular resistance in young adults. However, the acute response to IMST is unknown. We characterized BP, heart rate, and sympathetic nervous activity (SNA) in healthy young adults at baseline, during IMST, and in recovery. There was no acute effect of IMST on BP, however, there was significant IMST-related suppression of SNA that was of greater magnitude in women than men.
高强度、低容量吸气肌力量训练（IMST）对偶然的收缩压和全身血管阻力有有利影响。然而，IMST 对心率（HR）、血压（BP）和血管阻力的交感调节以及运动后恢复的轨迹的急性影响尚不清楚。我们招募了 14 名年轻成年人（7 名女性/7 名男性，年龄：22±2 岁）进行单次高强度 IMST（吸气阻力设定为最大吸气压力的 75%），重要的是，女性和男性受试者在目标吸气压力和目标吸气肌每呼吸做功方面相匹配。我们在基线、单次 IMST（包括 5 组 6 次吸气努力）和恢复期间连续记录 HR、BP 和节后、肌肉交感神经活动（MSNA）的逐搏变化。我们表明，单次 IMST 不会影响 BP 的变化，但是会导致 HR 显著增加（68.4±11.7 次/分钟与 85.4±13.6 次/分钟；<0.001）和 MSNA 显著下降（6.8±1.1 个/15 秒 bin；<0.001 与 3.6±0.6 个/15 秒 bin）与基线相比。值得注意的是，在男性中，MSNA 在恢复的第一分钟内恢复到基线水平，而在女性中，MSNA 抑制持续了 5 分钟。我们表明，在健康的年轻成年人中，高强度、低容量呼吸训练会导致 MSNA 的急性抑制。重要的是，女性的 MSNA 抑制程度和持续时间大于男性。以前的研究表明，6 周的高强度、低容量吸气肌力量训练（IMST）可降低年轻成年人的血压（BP）和全身血管阻力。然而，IMST 的急性反应尚不清楚。我们在基线、IMST 期间和恢复期间对健康年轻成年人的 BP、心率和交感神经活动（SNA）进行了描述。IMST 对 BP 没有急性影响，但是 SNA 与 IMST 有显著相关的抑制，女性的抑制程度大于男性。
