Science and Research Center Koper, Institute for Kinesiology Research, Koper, Slovenia.
Faculty of Kinesiology, University of Split, Split, Croatia.
Eur J Appl Physiol. 2022 Apr;122(4):903-917. doi: 10.1007/s00421-021-04843-w. Epub 2022 Jan 11.
The role of splenic emptying in O transport during aerobic exercise still remains a matter of debate. Our study compared the differences in spleen volume changes between aerobically trained and untrained individuals during step-transition supine cycling exercise at moderate-intensity. We also examined the relationship between spleen volume changes, erythrocyte release, and O uptake parameters.
Fourteen healthy men completed all study procedures, including a detailed medical examination, supine maximal O uptake ([Formula: see text] max.) test, and three step-transitions from 20 W to a moderate-intensity power output, equivalent to [Formula: see text] uptake at 90% gas exchange threshold. During these step-transitions pulmonary [Formula: see text], near-infrared spectroscopy of the vastus lateralis, and cardiovascular responses were continuously measured. In parallel, minute-by-minute ultrasonic measurements of the spleen were performed. Blood samples were taken before and immediately after step-transition cycling.
On average, [Formula: see text] max. was 10 mL kg min (p = 0.001) higher in trained compared to their aerobically untrained peers. In response to supine step-transition cycling, the splenic volume was significantly reduced, and the largest reduction (~ 106 to 115 mL, ~ 38%, p = 0.001) was similar in both aerobically trained and untrained individuals. Erythrocyte concentration and platelet count transiently increased after exercise cessation, with no differences observed between groups. However, the vastus lateralis deoxygenation amplitude was 30% (p = 0.001) greater in trained compared to untrained individuals. No associations existed between: (i) spleen volumes at rest (ii) spleen volume changes (%), (iii) resting hematocrit and oxygen uptake parameters.
Greater splenic emptying and subsequent erythrocyte release do not lead to a slower [Formula: see text], regardless of individual [Formula: see text] max. readings.
在有氧运动中，脾清除在 O 运输中的作用仍存在争议。本研究比较了在中等强度的仰卧位踏车运动中，经过有氧训练和未经训练的个体在台阶过渡期间脾脏体积变化的差异。我们还检查了脾脏体积变化、红细胞释放和 O 摄取参数之间的关系。
14 名健康男性完成了所有研究程序，包括详细的医学检查、仰卧位最大 O 摄取量 ([Formula: see text] max.) 测试和从 20 W 到中等强度功率输出的三次台阶过渡，相当于 90%气体交换阈值时的 [Formula: see text] 摄取量。在这些台阶过渡中，连续测量肺 [Formula: see text]、股外侧肌近红外光谱和心血管反应，同时对脾脏进行每分钟超声测量。在台阶过渡踏车运动前后采集血样。
平均而言，与未经训练的个体相比，训练有素的个体的 [Formula: see text] max. 高 10 mL·kg·min（p = 0.001）。对仰卧位台阶过渡踏车运动的反应，脾脏体积明显减小，最大减小量（106 到 115 mL，38%，p = 0.001）在训练有素和未经训练的个体中相似。运动停止后，红细胞浓度和血小板计数短暂增加，两组之间没有差异。然而，股外侧肌去氧幅度在训练有素的个体中比未经训练的个体高 30%（p = 0.001）。没有发现以下各项之间存在关联：（i）静息时脾脏体积；（ii）脾脏体积变化（%）；（iii）静息红细胞比容和 O 摄取参数。
无论个体的 [Formula: see text] max. 读数如何，更大的脾脏排空和随后的红细胞释放并不会导致 [Formula: see text] 更慢。
