Caretti D M, Whitley J A
US Army Edgewood Research, Development and Engineering Center, Aberdeen Proving Ground, MD 21010-5423, USA.
Ergonomics. 1998 Apr;41(4):501-11. doi: 10.1080/001401398186973.
The purpose of this study was to determine the effects of different inspiratory resistances on exercise performance and to describe physiological and subjective responses during constant load work of an intensity that elicits the maximum sensitivity to respiratory factors of respirator wear. Nine subjects (mean age 25.8 +/- 4.8 years) performed exhaustive treadmill exercise during constant load work of 80% of maximal aerobic capacity while inspiring against one of five randomly assigned inspiratory resistance conditions. For inspiratory resistances of 0.20 kPa (R1), 0.29 kPa (R2), 0.39 kPa (R3), and 0.49 kPa (R4), measured at a steady air flow rate of 85 L min-1, average performance times were 84, 75, 54, and 30% of the control condition. Performance time reductions were significant for R3 and R4 trials. Results also indicated a significantly reduced mean respiration rate, minute ventilation, and oxygen ventilatory equivalent (VE/VO2) for the R4 condition at exercise breakpoint compared to control. For resistances R1-R4, mean VE/VO2 were significantly reduced from control by approximately 12, 17, 19, and 31%. At breakpoint, mean ratings of perceived exertion were similar for control, R1, R2, and R3 conditions but were significantly lower for R4 versus control. Breathing comfort did not differ significantly between resistances below the R3 level, but discomfort was significantly greater for conditions R3 and R4. These findings suggest that the impact of the respiratory limitations of respirators can be diminished by employing respirators with inspiratory resistances below the R3 level.
本研究的目的是确定不同吸气阻力对运动表现的影响，并描述在恒定负荷工作期间的生理和主观反应，该恒定负荷工作的强度能引发对呼吸器佩戴者呼吸因素的最大敏感性。九名受试者（平均年龄25.8±4.8岁）在最大有氧能力的80%的恒定负荷工作期间，在随机分配的五种吸气阻力条件之一的情况下进行力竭性跑步机运动。对于在85 L min-1的稳定气流速率下测得的0.20 kPa（R1）、0.29 kPa（R2）、0.39 kPa（R3）和0.49 kPa（R4）的吸气阻力，平均运动时间分别为对照条件下的84%、75%、54%和30%。R3和R4试验的运动时间显著减少。结果还表明，与对照相比，在运动断点时，R4条件下的平均呼吸频率、分钟通气量和氧通气当量（VE/VO2）显著降低。对于阻力R1 - R4，平均VE/VO2比对照显著降低约12%、17%、19%和31%。在断点时，对照、R1、R2和R3条件下的平均主观用力感觉评分相似，但R4与对照相比显著更低。低于R3水平的阻力之间的呼吸舒适度没有显著差异，但R3和R4条件下的不适感显著更大。这些发现表明，通过使用吸气阻力低于R3水平的呼吸器，可以减轻呼吸器呼吸限制的影响。
