Many vertebrate animals employ anaerobic pathways during high‐speed exercise, even if it imposes an energetic cost during postexercise recovery, expressed as excess postexercise oxygen consumption (EPOC). In ectotherms such a fish, the initial anaerobic contribution to exercise is often substantial. Even so, fish may recover from anaerobic pathways as swimming exercise ensues and aerobic metabolism stabilizes, thus total energetic costs of exercise could depend on swimming duration and subsequent physiological recovery. To test this hypothesis, we examined EPOC in striped surfperch (Embiotoca lateralis) that swam at high speeds (3.25 L s⁻¹) during randomly ordered 2‐, 5‐, 10‐, and 20‐min exercise periods. We found that EPOC was highest after the 2‐min period (20.9 mg O₂ kg⁻¹) and lowest after the 20‐min period (13.6 mg O₂ kg⁻¹), indicating that recovery from anaerobic pathways improved with exercise duration. Remarkably, EPOC for the 2‐min period accounted for 72% of the total O₂ consumption, whereas EPOC for the 20‐min period only accounted for 14%. Thus, the data revealed a striking decline in the total cost of transport from 0.772 to 0.226 mg O₂·kg⁻¹·m⁻¹ during 2‐ and 20‐min periods, respectively. Our study is the first to combine anaerobic and aerobic swimming costs to demonstrate an effect of swimming duration on EPOC in fish. Clarifying the dynamic nature of exercise‐related costs is relevant to extrapolating laboratory findings to animals in the wild.

中文翻译：

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迷宫鱼运动后的过量耗氧量随着游泳时间的延长而减少：跨时间整合有氧和无氧代谢。

即使在运动后恢复过程中付出了高昂的代价，许多脊椎动物仍在高速运动中采用厌氧途径，表现为运动后的过量氧气消耗（EPOC）。在这样的鱼类中，最初对运动的厌氧贡献通常是很大的。即便如此，随着游泳运动的进行和有氧代谢的稳定，鱼可能会从厌氧途径中恢复过来，因此，运动的总精力成本可能取决于游泳时间和随后的生理恢复。为了检验该假设，我们检查了随机，有序的2分钟，5分钟，10分钟和20分钟运动期间以高速度（3.25 L s ^-1）游动的条纹冲浪者（Embiotocalateralis）的EPOC 。我们发现2分钟后EPOC最高（20.9 mg O ₂ kg ^-1），在20分钟后最低（13.6 mg O ₂  kg ^-1），表明随着运动时间的延长，厌氧途径的恢复也有所改善。值得注意的是，前2分钟的EPOC占总O ₂消耗量的72％，而前20分钟的EPOC仅占14％。因此，数据显示运输总成本从0.772急剧下降至0.226 mg O ₂ ·kg ^-1 ·m ^-1分别在2分钟和20分钟内。我们的研究是第一个结合厌氧和有氧游泳费用来证明游泳时间对鱼类EPOC的影响的研究。阐明与运动有关的费用的动态性质与将实验室发现外推到野外动物有关。