加速度數據量化肥胖族群身體活動(physical activity, PA)強度的研究證據有限,近年來研究者嘗試建立肥胖族群身體活動強度個別化加速度閾值。因此,本研究目的在探討以市售穿戴式裝置估計肥胖成人久坐行為(sedentary behavior, SB)、輕度、中度與費力PA(light PA [LPA], moderate to vigorous PA [MVPA])的手腕加速度閾值。實驗招募52名無規律運動肥胖成人,先測量5分鐘坐姿安靜休息攝氧量,隨後進行站姿休息與漸增負荷走路運動,速度階段分別訂為走路運動3.2、4.0、4.8、5.6、6.4 km/hr,每階段測驗時間為5分鐘。全程記錄X、Y、Z軸加速度與攝氧量,三軸加速度值依√(X^2 + Y^2 + Z^2) - g,轉換每1秒加速度計數值(acceleration count, ACC),而安靜休息與運動攝氧量轉換為代謝當量(metabolic equivalent of task, MET)。分析結果顯示:男性、女性及全部研究對象ACC與METs相關程度為r = .83~.86。此外,ACC判定不同PA強度閾值模型皆具有極佳的鑑別力,而男性與女性SB加速度閾值分別為10.10mg與13.75 mg、LPA為41.20 mg與32.90 mg、MVPA為105.70 mg與109.25 mg。本研究結論認為以穿戴式裝置可有效建立男性與女性肥胖成人SB、LPA、MVPA的手腕加速度閾值,並可作為長時間量化日常生活PA強度的評估工具。
There is limited research evidence of acceleration data to quantify physical activity (PA) intensity in obese people. Recently, researchers have tended to establish individualized acceleration thresholds for obese people regarding PA levels. Therefore, the purpose of this study was to estimate the wrist acceleration thresholds of sedentary behavior (SB), and light, moderate to vigorous PA (LPA, MVPA) in obese adults using a wearable device. A total of 52 obese adults were recruited in the current study. Subjects performed a 5-minute seated resting oxygen consumption measurement at the beginning of the experiment, and followed by standing resting and incremental continuous walking test. The speeds of continuous walk stages were set at 3.2, 4.0, 4.8, 5.6, 6.4 km/hr. Each phase lasted for 5 minutes. The accelerations along the X, Y, Z axes and oxygen uptake were recorded during the entire experiment. Acceleration count (ACC) per second was calculated by the formula with √(X^2 + Y^2 + Z^2) - g at the triaxial acceleration values. Metabolic equivalent of task (MET) was derived from resting and exercising oxygen intake (VO_2). Results showed that: The correlation between ACC and METs was r = .83-.86 for all subjects. In addition, ACC has an excellent discriminative power for different PA intensity threshold models. SB acceleration threshold in men was 10.10 mg and 13.75 mg in women. LPA in men was 41.20 mg and 32.90 mg in women, MVPA was 105.70 mg in men and 109.25 mg in women. We conclude that the wearable device is an effective tool to establishing wrist acceleration thresholds in SB and LPA to MVPA in obese adults. It will be an effective tool for quantifying long-term PA intensity in daily life.