We investigated the acute physiological responses of tapered flow resistive loading (TFRL) at 30, 50 and 70 % maximal inspiratory pressure (PI_max) in 12 healthy adults to determine an optimal resistive load. Increased end-inspiratory rib cage and decreased end-expiratory abdominal volumes equally contributed to the expansion of thoracoabdominal tidal volume (captured by optoelectronic plethysmography). A significant decrease in end-expiratory thoracoabdominal volume was observed from 30 to 50 % PI_max, from 30 to 70 % PI_max, and from 50 to 70 % PImax. Cardiac output (recorded by cardio-impedance) increased from rest by 30 % across the three loading trials. Borg dyspnoea increased from 2.36 ± 0.20 at 30 % PI_max, to 3.45 ± 0.21 at 50 % PI_max, and 4.91 ± 0.25 at 70 % PI_max. End-tidal CO₂ decreased from rest during 30, 50 and 70 %PI_max (26.23 ± 0.59, 25.87 ± 1.02 and 24.30 ± 0.82 mmHg, respectively). Optimal intensity for TFRL is at 50 % PI_max to maximise global respiratory muscle and cardiovascular loading whilst minimising hyperventilation and breathlessness.

我们研究了12 名健康成人在 30%、50% 和 70% 最大吸气压力 (PI _max )下的锥形流动阻力负荷 (TFRL) 的急性生理反应，以确定最佳阻力负荷。吸气末胸腔增加和呼气末腹部容积减少同样有助于胸腹潮气量的扩大（通过光电体积描记法捕获）。观察到呼气末胸腹容积从 30% 至 50% PI _max、从 30 至 70% PI _max和从 50% 至 70% PImax显着降低。在三个负荷试验中，心输出量（通过心阻抗记录）从静止状态增加了 30%。Borg 呼吸困难从 2.36 ± 0.20 增加到 30 % PI _max，至3.45±0.21，在50％PI_最大值，和4.91±0.25，在70％PI_最大值。在30、50和 70%PI_最大值期间，呼气末 CO ₂从静止状态下降（分别为 26.23 ± 0.59、25.87 ± 1.02 和 24.30 ± 0.82 mmHg）。TFRL 的最佳强度为 50% PI_最大值，以最大限度地提高整体呼吸肌肉和心血管负荷，同时最大限度地减少换气过度和呼吸困难。