Brotto Andrew R, de Waal Stephanie, D'Souza Andrew W, Beaudry Rhys I, Ehnes Cameron M, Collins Sophie É, Fuhr Desi P, van Diepen Sean, Stickland Michael K
Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada.
J Appl Physiol (1985). 2025 Jan 1;138(1):301-310. doi: 10.1152/japplphysiol.00447.2024. Epub 2024 Dec 16.
Endurance-trained athletes exhibit a greater diffusing capacity for carbon monoxide (DLCO) at rest and during exercise as compared with untrained individuals; however, the mechanism(s) are unclear. The supine position translocates blood centrally and can be used to investigate DLCO responses independent of metabolic rate. We hypothesized that endurance-trained individuals would have a greater DLCO response to postural change at rest as compared with untrained and that the supine position would elicit a greater DLCO response as compared with the upright position during exercise in both groups. Fourteen endurance-trained (Trained) individuals (V̇o: 61.1 ± 4.4 mL·kg·min) and 14 untrained individuals (V̇o: 37.4 ± 3.0 mL·kg·min) completed DLCO maneuvers at rest and during exercise in the upright and supine position. At rest, there was a significant group-by-position interaction ( = 0.02) effect on DLCO with post hoc analysis determining DLCO increased from upright to supine position in Trained ( < 0.01), but not untrained ( = 0.58). There was no effect of position on exercising DLCO ( = 0.16) regardless of group; however, pulmonary capillary blood volume (V) was increased with supine exercise ( = 0.03). There was an apparent plateau in DLCO and V in the Trained group near-maximal exercise as Trained failed to increase DLCO ( = 0.25) and Vc ( = 0.46) up to near-maximal exercise. Trained individuals demonstrate greater DLCO recruitment with postural change at rest suggesting a greater ability to recruit/distend the pulmonary microvasculature. However, the supine position did not augment DLCO as compared with upright position in Trained individuals near-maximal exercise, suggesting a plateau may be reached at maximal exercise. We demonstrate that the supine position increases resting DLCO significantly more in endurance-trained individuals as compared with untrained individuals. Furthermore, the supine position increases pulmonary capillary blood volume, but not diffusing capacity during exercise. Lastly, there was an apparent plateau in DLCO and V in the Trained group suggesting the pulmonary microvasculature may reach a morphological limit.
与未经训练的个体相比，耐力训练的运动员在静息和运动时表现出更高的一氧化碳弥散能力（DLCO）；然而，其机制尚不清楚。仰卧位可使血液向中心转移，可用于研究独立于代谢率的DLCO反应。我们假设，与未经训练的个体相比，耐力训练的个体在静息时对姿势变化的DLCO反应更大，并且在两组运动期间，仰卧位比直立位引起的DLCO反应更大。14名耐力训练的（训练有素的）个体（V̇o：61.1±4.4 mL·kg·min）和14名未经训练的个体（V̇o：37.4±3.0 mL·kg·min）在静息和运动时分别在直立位和仰卧位完成了DLCO操作。静息时，存在显著的组×体位交互作用（P = 0.02）对DLCO有影响，事后分析确定训练有素的个体中DLCO从直立位到仰卧位增加（P < 0.01），但未经训练的个体没有增加（P = 0.58）。无论组别如何，体位对运动时的DLCO均无影响（P = 0.16）；然而，仰卧位运动时肺毛细血管血容量（Vc）增加（P = 0.03）。在训练有素的组接近最大运动时，DLCO和Vc出现明显的平台期，因为训练有素的个体在接近最大运动时未能增加DLCO（P = 0.25）和Vc（P = 0.46）。训练有素的个体在静息时因姿势变化表现出更大的DLCO募集，表明其募集/扩张肺微血管的能力更强。然而，在训练有素的个体接近最大运动时，仰卧位与直立位相比并未增加DLCO，表明在最大运动时可能达到平台期。我们证明，与未经训练的个体相比，仰卧位在耐力训练的个体中显著增加静息时的DLCO。此外，仰卧位增加肺毛细血管血容量，但在运动时不增加弥散能力。最后，训练有素的组中DLCO和Vc出现明显的平台期，表明肺微血管可能达到形态学极限。
