a Studies , Research and Sport Medicine Centre (CEIMD), Government of Navarre , Pamplona , Spain.
b Deparment of Physical Education and Sport, Faculty of Education and Sport, Physical Activity and Sport Sciences Section , University of the Basque Country (UPV/EHU) , Vitoria-Gasteiz , Basque Country, Spain.
Eur J Sport Sci. 2019 May;19(4):539-548. doi: 10.1080/17461391.2018.1539528. Epub 2018 Nov 8.
To investigate how objectively measured physical activity (PA) levels differ according to absolute moderate intensity recommendation (3-6 METs) and relative to individual lactate thresholds (LT1 and LT2), and to verify if high-fit women record higher PA levels compared to women with lower aerobic fitness.
Seventy-five postmenopausal women performed an incremental exercise test and several constant-velocity tests wearing an accelerometer to identify the activity counts (ct min) corresponding to LT1 and LT2. Individual linear regression determined activity counts cut-points for each intensity: (1) sedentary (<200 ct min), (2) light (from 200 ct min to ct min at LT1), (3) moderate (ct min between LT1 and LT2) and (4) vigorous (ct min> LT2). Participants then wore an accelerometer during a week to measure the time spent at each PA intensity level.
According to absolute intensity categorisation, high-fit postmenopausal women recorded twice as much time at moderate-to-vigorous PA (MVPA) (P < 0.01) than low-fit women. However, when PA intensity was calculated relative to individual lactate thresholds, MVPA was significantly reduced by half (P < 0.01) and the data revealed no differences (P = 0.62) between groups (∼20 min day at MVPA).
Accelerometer cut-points derived from absolute moderate-intensity recommendations overestimated MVPA. Similar time at MVPA was recorded by high- and low-fit postmenopausal women when the cut-points were tailored to individual lactate thresholds. A more accurate estimation of PA behaviour could be provided with the use of individually tailored accelerometer cut-points.
研究客观测量的体力活动 (PA) 水平根据绝对中等强度推荐 (3-6 METs) 和相对于个体乳酸阈值 (LT1 和 LT2) 有何差异，并验证高适应女性与低有氧健身女性相比是否记录更高的 PA 水平。
75 名绝经后妇女进行了递增运动测试和多次等速测试，同时佩戴加速度计以确定与 LT1 和 LT2 相对应的活动计数 (ct min)。个体线性回归确定了每个强度的活动计数切点：（1）久坐 (<200 ct min)，（2）轻度 (200 ct min 至 LT1 对应的 ct min)，（3）中度 (LT1 和 LT2 之间的 ct min) 和 (4) 剧烈 (ct min> LT2)。然后，参与者在一周内佩戴加速度计以测量每个 PA 强度水平所花费的时间。
根据绝对强度分类，高适应绝经后妇女记录的中度至剧烈体力活动 (MVPA) 时间是低适应妇女的两倍 (P < 0.01)。然而，当 PA 强度相对于个体乳酸阈值计算时，MVPA 显著减少了一半 (P < 0.01)，并且数据显示两组之间没有差异 (P = 0.62)（MVPA 约 20 分钟/天）。
基于绝对中等强度推荐的加速度计切点高估了 MVPA。当切点根据个体乳酸阈值进行调整时，高适应和低适应绝经后妇女记录的 MVPA 时间相似。使用个体定制的加速度计切点可以更准确地估计 PA 行为。
