Kell Robert T, Bhambhani Yagesh
Faculty of Physical Education and Recreation, University of Alberta, T6J-2H9, Edmonton, Alberta, Canada.
Eur J Appl Physiol. 2003 Sep;90(1-2):1-9. doi: 10.1007/s00421-002-0776-0. Epub 2003 May 21.
The purposes of this study were twofold. First, to evaluate the cardiorespiratory and muscle oxygenation (OXY)/blood volume (BV) responses during repetitive incremental lifting and lowering (RILL) in healthy males and females. Second, to develop a predictive equation for predicting peak aerobic power (VO(2peak)) during RILL from the cardiorespiratory, OXY/BV and body composition variables. Fourteen males and 18 females [mean (SD) for age, height and body mass were: 29.6 (8.2) years; 1.75 (0.07) m; 78.9 (10.4) kg and 23.9 (2.1) years; 1.63 (0.06) m; 62.3 (6.3) kg, respectively] completed a RILL from floor to table height at 10 lifts/min to voluntary fatigue. Cardiorespiratory responses were measured using open circuit spirometry and hemodynamic trends were monitored bilaterally at the third lumbar vertebra via near infrared spectroscopy. Significant sex differences ( p<0.05) were observed for the peak values of oxygen uptake (VO(2peak)), ventilation rate (V(E)), oxygen pulse, BV-max and BV-delta. Erector spinae OXY decreased systematically until VO(2peak )was attained, while BV decreased until approximately 50% of VO(2peak) and then leveled off. Stepwise regression analysis indicated that approximately 75% of the variance in VO(2peak )was predicted from cardiorespiratory, hemodynamic and body composition variables, with the most important predictors for absolute and relative VO(2peak )being V(E) ( r=0.75) and fat mass ( r=-0.63) respectively. Inclusion of left side OXY/BV responses increased the predictability of the common variance in VO(2peak )from 40% to 74%, implying that muscle hemodynamics play an important role in determining VO(2peak )during RILL.
本研究有两个目的。其一，评估健康男性和女性在重复递增举升和放下（RILL）过程中的心肺和肌肉氧合（OXY）/血容量（BV）反应。其二，根据心肺、OXY/BV和身体成分变量，建立一个预测方程，用于预测RILL期间的最大有氧功率（VO₂peak）。14名男性和18名女性[年龄、身高和体重的平均值（标准差）分别为：29.6（8.2）岁；1.75（0.07）米；78.9（10.4）千克和23.9（2.1）岁；1.63（0.06）米；62.3（6.3）千克]以每分钟10次的举升速度从地面举升至桌面高度，直至自愿疲劳，完成了RILL。使用开路肺量计测量心肺反应，并通过近红外光谱法在第三腰椎双侧监测血流动力学趋势。在摄氧量峰值（VO₂peak）、通气率（V̇E）、氧脉搏、BV-最大值和BV-变化量的峰值方面观察到显著的性别差异（p<0.05）。竖脊肌氧合在达到VO₂peak之前系统性下降，而血容量在达到约50%的VO₂peak之前下降，然后趋于平稳。逐步回归分析表明，VO₂peak中约75%的方差可由心肺、血流动力学和身体成分变量预测，对于绝对和相对VO₂peak而言，最重要的预测因子分别是V̇E（r=0.75）和脂肪量（r=-0.63）。纳入左侧OXY/BV反应后，VO₂peak共同方差的可预测性从40%提高到74%，这意味着肌肉血流动力学在RILL期间决定VO₂peak方面起着重要作用。
