Lawler J M, Powers S K, Hammeren J, Martin A D
Department of Health and Kinesiology, Texas A&M University, College Station 77843-4243.
Med Sci Sports Exerc. 1993 Nov;25(11):1259-64.
The oxygen cost of treadmill running is well documented in young adult rats. However, to our knowledge there are no detailed reports concerning the oxygen cost of treadmill running in senescent rats. Young adult (4 months; N = 8) and senescent (24 months; N = 8) female Fischer-344 rats were tested for O2 cost of treadmill running. One-half of the animals tested in each age group had completed 10 wk of endurance training. Oxygen cost of treadmill running, using a flow-through system, was measured on a per minute basis from 7-10 min of each work bout and averaged. Separate work bouts were performed at 0%, 5%, and 10% grade at 15, 20, 25, and 30 m.min-1. Oxygen cost of treadmill running for trained rats for all speeds and grades were not significantly different (P = 0.77) from untrained animals; thus, data were pooled for oxygen cost of running. Results revealed significantly lower (P < 0.05) VO2 (expressed as ml.kg-1.min-1) for senescent rats vs young adult rats rest and at all comparable treadmill grades and speeds except for 5% grade, 25 m.min-1 and 10% grade, 20 m.min-1. In addition, resting VO2 was significantly lower (P < 0.05) in old rats when compared with young rats. Thus, we conclude that the oxygen cost of treadmill running is lower for 24-month-old rats than in 4-month-old rats except at higher work levels.
成年幼鼠跑步机跑步的耗氧量已有充分记录。然而，据我们所知，尚无关于衰老大鼠跑步机跑步耗氧量的详细报告。对成年幼龄（4个月；N = 8）和老龄（24个月；N = 8）雌性Fischer-344大鼠进行跑步机跑步耗氧量测试。每个年龄组中一半的受试动物完成了10周的耐力训练。使用流通系统，在每次运动回合的7 - 10分钟内每分钟测量跑步机跑步的耗氧量并求平均值。分别在0%、5%和10%的坡度下，以15、20、25和30米·分钟⁻¹的速度进行不同的运动回合。训练大鼠在所有速度和坡度下的跑步机跑步耗氧量与未训练动物相比无显著差异（P = 0.77）；因此，将跑步耗氧量数据合并。结果显示，与成年幼龄大鼠相比，老龄大鼠在休息时以及除5%坡度、25米·分钟⁻¹和10%坡度、20米·分钟⁻¹外的所有可比跑步机坡度和速度下，VO₂（以毫升·千克⁻¹·分钟⁻¹表示）显著更低（P < 0.05）。此外，老龄大鼠的静息VO₂与幼龄大鼠相比显著更低（P < 0.05）。因此，我们得出结论，24月龄大鼠跑步机跑步的耗氧量低于4月龄大鼠，但在较高运动水平时除外。
