Bartlett D
J Appl Physiol Respir Environ Exerc Physiol. 1977 May;42(5):717-21. doi: 10.1152/jappl.1977.42.5.717.
Breath holding to the breaking point was studied at FRC in six healthy subjects in the sitting position. Breath-holding time increased with successive trials within experimental sessions in all subjects. To study the influence of Valsalva and Mueller maneuvers on breath-holding performance, sustained inspiratory or expiratory effort against an occluded mouthpiece was initiated 5 s before the anticipated breaking point, determined in previous trials. The subject tried to maintain a target mouth pressure of +20 or -20 cmH2O, displayed on an oscilloscope, for the remainder of the breath hold. Both types of maneuver consistently prolonged breath-holding time in all subjects. However, a control maneuver, in which the subjects squeezed rubber bulbs with their hands, was equally effective in prolonging breath-holding time. The results demonstrate the important influence of psychological factors on breath-holding performance and emphasize the need for caution in the interpretation of effects of "relieving maneuvers" on breath-holding time.
在FRC状态下，对6名坐位健康受试者的屏气至极限点进行了研究。在所有受试者的实验过程中，屏气时间随着连续试验而增加。为了研究瓦尔萨尔瓦动作和米勒动作对屏气表现的影响，在先前试验确定的预期极限点前5秒开始，对着阻塞的咬嘴进行持续吸气或呼气努力。受试者在屏气的剩余时间内试图维持示波器上显示的+20或-20 cmH2O的目标口腔压力。两种动作在所有受试者中均持续延长了屏气时间。然而，一种对照动作，即受试者用手挤压橡胶球，在延长屏气时间方面同样有效。结果表明心理因素对屏气表现有重要影响，并强调在解释“缓解动作”对屏气时间的影响时需要谨慎。
