Welsman J R, Armstrong N
PEA Research Centre, School of Education, University of Exeter, UK.
Br J Sports Med. 1992 Dec;26(4):228-32. doi: 10.1136/bjsm.26.4.228.
This study examined the relationship between daily physical activity and aerobic fitness in 11-16-year-olds. Habitual physical activity was assessed in 28 boys (mean(s.d.) age 13.6(1.3) years) and 45 girls (mean(s.d) age 13.7(1.3) years) from minute-by-minute heart rate monitoring during 3 school days. Aerobic fitness was assessed by determining the percentage peak VO2 at blood lactate reference values of 2.5 and 4.0 mmol l-1 during incremental treadmill running. The 4.0 mmol l-1 level occurred at a mean(s.d.) value of 89(7)% peak VO2 in both boys and girls and mean(s.d.) values at the 2.5 mmol l-1 level were 82(9)% peak VO2 in girls. Mean(s.d.) percentage time with heart rates at or above 140 beats min-1 was 6(3)% in boys and 5(3)% in girls. Corresponding values for percentage time at or above 160 beats min-1 were 3(2) for boys and 2(1) for girls. The number of 10- and 20-min periods of activity with the heart rate sustained above the 140 and 160 beats min-1 thresholds were also totalled over the 3 days. No significant relationships were identified between percentage peak VO2 at the 2.5 or 4.0 mmol l-1 blood lactate reference levels and either percentage time or number of 10- or 20-min periods above 140 or 160 beats min-1 (P > 0.05). These results support the hypothesis that daily physical activity levels in 11-16-year-old children do not stress aerobic metabolism sufficiently to influence aerobic fitness.
本研究调查了11至16岁青少年日常身体活动与有氧适能之间的关系。通过在3个上学日逐分钟监测心率，对28名男孩（平均（标准差）年龄13.6（1.3）岁）和45名女孩（平均（标准差）年龄13.7（1.3）岁）的习惯性身体活动进行了评估。在递增式跑步机跑步过程中，通过测定血乳酸参考值为2.5和4.0 mmol l-1时的峰值摄氧量百分比来评估有氧适能。4.0 mmol l-1水平时，男孩和女孩的峰值摄氧量平均（标准差）值均为89（7）%，女孩在2.5 mmol l-1水平时的平均（标准差）值为82（9）%峰值摄氧量。男孩心率处于或高于140次/分钟的平均（标准差）时间百分比为6（3）%，女孩为5（3）%。心率处于或高于160次/分钟的相应时间百分比，男孩为3（2）%，女孩为2（1）%。在这3天里，还统计了心率持续高于140和160次/分钟阈值的10分钟和20分钟活动时段的数量。在血乳酸参考水平为2.5或4.0 mmol l-1时的峰值摄氧量百分比与心率高于140或160次/分钟的时间百分比或10分钟或20分钟时段的数量之间，未发现显著相关性（P>0.05）。这些结果支持了这样一种假设，即11至16岁儿童的日常身体活动水平对有氧代谢的压力不足以影响有氧适能。
