ABSTRACT

The activPAL is a widely-used measure of sedentary time but few studies have evaluated its ability to estimate physical activity intensity. This study determined the accuracy of the algorithm used by the activPAL to predict metabolic equivalents (METs) from cadence and a curvilinear cadence-METs equation individualized for height. Thirty-six healthy adults (25 ± 6 years) completed a progressive walking protocol. Stepping cadence was video recorded and METs were determined via indirect calorimetry. Manually-counted cadence was input into the activPAL and curvilinear equations. The internal activPAL equation overpredicted METs at slower cadences (<120 steps/minute) but underpredicted METs at faster cadences (>120 step/minute) (proportional bias, p < .001). Conversely, the curvilinear equation exhibited neither fixed (p = .37) nor proportional bias (p = .07), and a lower absolute MET difference [0.87 ± 0.65 (range:0.0–3.2) vs. 0.56 ± 0.45 (range:0.0–2.7) METs]. The linear activPAL equation poorly estimates METs from stepping cadence but these inaccuracies may be lessened through the use of an individualized curvilinear equation.

摘要

activPAL是久坐时间的一种广泛使用的度量标准，但很少有研究评估其估计体力活动强度的能力。这项研究确定了activPAL用来从节奏和针对身高个性化的曲线节奏-METs方程预测代谢当量（MET）的算法的准确性。三十六名健康成年人（25±6岁）完成了渐进式步行方案。记录脚步节奏，并通过间接量热法测定MET。将手动计数的节奏输入到activPAL和曲线方程中。内部activPAL方程以较低的节奏（<120步/分钟）高估了MET，但以较快的节奏（> 120步/分钟）低估了MET（比例偏差，p<.001）。相反，曲线方程既不显示固定值（p = .37），也不显示比例偏差（p = .07），并且绝对MET差值较低[0.87±0.65（范围：0.0–3.2）与0.56±0.45（范围：0.0） –2.7）METs]。线性activPAL方程无法通过步进节奏估算MET，但可以通过使用个性化曲线方程来减少这些不准确性。