Rowland T W, Cunningham L N
Department of Pediatrics, Baystate Medical Center, Springfield, Mass. 01199.
Chest. 1992 Feb;101(2):485-9. doi: 10.1378/chest.101.2.485.
The leveling of oxygen uptake at high work loads has been utilized to define maximal VO2 during progressive exercise testing. Exercise studies in children have indicated, however, that a VO2 plateau can commonly be demonstrated in less than one half of subjects. To examine the potential contributions of subject effort, aerobic fitness, and nonaerobic performance to this variability, 15 children ages 7 to 10 years performed progressive treadmill walking to exhaustion with a ramp protocol. The VO2 plateau was defined as a change in VO2 during the final minute of exercise less than 2 SD below the mean of increases between the previous 4 to 5 submaximal minutes. Five subjects (33.3 percent) demonstrated a plateau. No significant differences in mean peak VO2, heart rate, or respiratory exchange ratio were observed between plateau and nonplateau groups. Testing results of speed (50-yard sprint) and leg power (vertical jump) were also similar. These findings suggest that following: (1) subject effort, aerobic fitness, and nonaerobic factors do not explain the presence or absence of a VO2 plateau during exercise testing of children; and (2) a VO2 plateau should not be used as a requirement for defining VO2max during treadmill testing in this age group.
在递增运动测试中，高工作负荷下摄氧量的平稳状态已被用于定义最大摄氧量（VO₂max）。然而，针对儿童的运动研究表明，在不到一半的受试者中通常可显示出VO₂平台期。为了研究受试者努力程度、有氧适能和无氧运动表现对这种变异性的潜在影响，15名7至10岁的儿童采用斜坡方案在跑步机上进行递增步行直至力竭。VO₂平台期定义为运动最后一分钟内VO₂的变化低于前4至5个次最大运动分钟期间增加平均值的2个标准差。5名受试者（33.3%）表现出平台期。在平台期组和非平台期组之间，平均峰值VO₂、心率或呼吸交换率未观察到显著差异。速度测试（50码短跑）和腿部力量测试（垂直跳跃）结果也相似。这些发现表明：（1）受试者努力程度、有氧适能和无氧因素并不能解释儿童运动测试中VO₂平台期的出现与否；（2）在该年龄组的跑步机测试中，VO₂平台期不应被用作定义VO₂max的必要条件。
