Caretti D M, Szlyk P C, Sils I V
Comparative Physiology Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA.
Respir Physiol. 1992 Nov;90(2):201-11. doi: 10.1016/0034-5687(92)90081-7.
Ventilatory patterns and respiratory timing were measured in 14 subjects during cycling (CYC) and treadmill exercise (TM) at similar leg frequencies (fLEG) to determine if mode of exercise affects patterns of ventilation and respiratory timing. Measurements of breathing frequency (fR), tidal volume (VT), expired ventilation (VE), and inspiratory (TI) and expiratory (TE) time were obtained at fLEG of 50, 70, and 90 rev.min-1 (rpm) for CYC and at similar incremental fLEG (strides.min-1; spm) during TM achieved by increasing belt speed at 0% grade. CYC exercise intensity was approximately 50% VO2,max at all fLEG, whereas VO2 increased progressively with TM. fR increased significantly (P < 0.001) with increasing fLEG of TM (20.5 +/- 4.6, 25.4 +/- 5.8, and 36.3 +/- 7.6 breaths.min-1; mean +/- SD), but during CYC fR changed significantly (P < 0.05) only between fLEG of 70 and 90 rpm (25.0 +/- 5.9 vs 28.5 +/- 6.9 breaths.min-1). Both average breath TI and TE obtained by grouping into incremental ranges of fR decreased significantly (P < 0.05) with increasing fR up to 36 breaths.min-1 and the relationships of TI and TE to fR, TI to TE, and central inspiratory drive (VT/TI) to VE were the same for CYC and TM. Group average fR and fLEG were synchronized during TM, but individual subjects did not exhibit a high degree of entrainment. This study shows respiratory timing patterns to be independent of mode of exercise over the range of fR observed when describing patterns by grouping into incremental ranges of fR.
在14名受试者进行骑行（CYC）和跑步机运动（TM）时，以相似的腿部频率（fLEG）测量通气模式和呼吸时间，以确定运动模式是否会影响通气模式和呼吸时间。在CYC中，分别在fLEG为50、70和90转/分钟（rpm）时测量呼吸频率（fR）、潮气量（VT）、呼出通气量（VE）以及吸气时间（TI）和呼气时间（TE）；在TM中，通过在0%坡度下增加皮带速度，在相似的递增fLEG（步/分钟；spm）下进行测量。CYC运动强度在所有fLEG下约为最大摄氧量（VO2,max）的50%，而TM时VO2则逐渐增加。TM的fLEG增加时，fR显著增加（P < 0.001）（分别为20.5±4.6、25.4±5.8和36.3±7.6次呼吸/分钟；平均值±标准差），但在CYC中，fR仅在70和90 rpm的fLEG之间有显著变化（P < 0.05）（分别为25.0±5.9和28.5±6.9次呼吸/分钟）。将fR分组为递增范围后得到的平均吸气时间TI和呼气时间TE，在fR增加至36次呼吸/分钟之前均显著减少（P < 0.05），并且CYC和TM中TI与fR、TI与TE以及中枢吸气驱动（VT/TI）与VE的关系相同。TM期间组平均fR和fLEG是同步的，但个体受试者并未表现出高度的同步性。本研究表明，当按fR的递增范围分组来描述模式时，在观察到的fR范围内，呼吸时间模式与运动模式无关。
