Department of Coaching Education, Faculty of Sports Sciences, Adnan Menderes University, Aydin, Republic of Türkiye, Department of Coaching Education, Faculty of Sports Sciences, Ege University, Izmir, Republic of Türkiye.
Physiol Res. 2023 Jul 14;72(3):319-327. doi: 10.33549/physiolres.935068.
Stroke volume (SV), heart rate (HR) and arterio-venous O2 difference (a-vO2diff) responses to heavy and severe-intensity exercise have been well documented; however, there is a lack of information on the SV, HR and a v-O2diff responses of work rates within extreme exercise domain. The aim of this study was, therefore, to focus on central and peripheral components of VO2 responses to exercises performed within the heavy, severe and extreme exercise domain. Eight well-trained male cyclists participated in this study. Maximal O2 consumption (VO2max) and corresponding work rate (P@VO2max) were determined by multisession constant work rate exercises. Cardiovascular responses to exercises were evaluated by nitrous-oxide rebreathing method with work rates from 40 % to 160 % of P@VO2max, VO2max corresponded to 324+/-39.4 W; however, maximal SV responses occurred at 205+/-54.3 W (p<0.01). Maximal cardiac output (Q), HR, and a vO2diff responses were revealed by the P@VO2max. VO2 response to exercise significantly decreased from severe-intense exercises to the first work rate of extreme exercise domain due to significant decreases in Q, SV, and HR responses (p<0.05), except a v-O2diff (p>0.05). Moreover, non-significant decreases in Q, SV, and a v-O2diff were evaluated as response to increase in work rate belonging to extreme work rates (p>0.05), except the HR (p<0.05). Work rates within the lower district of the extreme exercise domain have an important potential to improve peripheral component of VO2, while the P@VO2max seems the most appropriate intensity for aerobic endurance development as it maximizes the central component of VO2max.
运动中每搏输出量（SV）、心率（HR）和动静脉氧差（a-vO2diff）对高强度和极强度运动的反应已有充分记录；然而，对于极强度运动范围内的工作率的 SV、HR 和 a-v-O2diff 反应，信息仍然缺乏。因此，本研究的目的是关注在高强度、极强度运动范围内进行的运动中 VO2 反应的中枢和外周成分。8 名训练有素的男性自行车手参加了这项研究。通过多会话恒功运动来确定最大耗氧量（VO2max）和相应的工作率（P@VO2max）。通过使用一氧化二氮再呼吸法评估运动时的心血管反应，工作率从 40%到 160%的 P@VO2max，VO2max 对应 324+/-39.4W；然而，最大 SV 反应发生在 205+/-54.3W（p<0.01）。最大心输出量（Q）、HR 和 a-vO2diff 反应由 P@VO2max 揭示。由于 Q、SV 和 HR 反应的显著下降（p<0.05），除了 a-v-O2diff（p>0.05）外，运动的 VO2 反应从高强度运动到极强度运动的第一个工作率显著下降。此外，在属于极强度工作率的工作率增加时，Q、SV 和 a-v-O2diff 的非显著下降被评估为反应（p>0.05），除了 HR（p<0.05）。极强度运动范围的较低区域的工作率具有改善 VO2 的外周成分的重要潜力，而 P@VO2max 似乎是有氧耐力发展的最合适强度，因为它使 VO2max 的中枢成分最大化。
