Sirichana Worawan, Dolezal Brett A, Neufeld Eric V, Wang Xiaoyan, Cooper Christopher B
Exercise Physiology Research Laboratory, Departments of Medicine and Physiology, David Geffen School of Medicine, University of California at Los Angeles, USA; Division of Pulmonary and Critical Care Medicine, Department of Medicine, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Thailand.
Exercise Physiology Research Laboratory, Departments of Medicine and Physiology, David Geffen School of Medicine, University of California at Los Angeles, USA.
J Sci Med Sport. 2017 Aug;20(8):761-765. doi: 10.1016/j.jsams.2017.01.233. Epub 2017 Jan 25.
Triaxial accelerometry is commonly used to estimate oxygen uptake (VO) and energy expenditure in health and fitness studies. We tested the correlation of a triaxial accelerometer in terms of a summation of vector magnitudes with gravity subtracted (SVMgs) and measured VO for different daily physical activities.
Original research, cross-sectional.
Twenty volunteers wore a triaxial accelerometer on both wrists while performing 12 assigned daily physical activities for 6min for each activity. The VO was determined by indirect calorimetry using a portable metabolic measurement system. The last 3min of each activity was assumed to represent steady-state. The VO measured during these periods was averaged and converted into metabolic equivalents (METs).
The range of VO for all activities was 0.18-3.2L/min (0.8-12.2 METs). Significant differences in SVMgs existed between accelerometer placements on the dominant (120.9±8.7gmin) versus non-dominant hand (99.9±6.8gmin; P=0.016) for the lowest levels of physical activity defined as <1.5 METs. Piecewise linear regression model using 6 METs as the transition point showed similar significant correlations for the non-dominant wrist (r=0.85; P<0.001) and the dominant wrist (r=0.86; P<0.001). Using the non-dominant wrist below 6 METs, the slope of the relationship between SVMgs and METs was 105.3±4.3 (95% CI 96.9 to 113.7) indicating an increase in SVMgs of approximately 100 units for every MET increase in oxygen uptake.
Wrist-worn triaxial accelerometry reliably predicted energy expenditure during common physical activities <6 METs. More consistent correlations were found when the accelerometer was worn on the non-dominant wrist rather than the dominant wrist.
在健康与健身研究中，三轴加速度计常用于估算摄氧量（VO）和能量消耗。我们测试了一种三轴加速度计在减去重力后的矢量大小总和（SVMgs）方面与不同日常身体活动的测量VO之间的相关性。
原创性研究，横断面研究。
20名志愿者在进行12项指定的日常身体活动时，每只手腕都佩戴一个三轴加速度计，每项活动持续6分钟。使用便携式代谢测量系统通过间接量热法测定VO。假设每项活动的最后3分钟代表稳态。将这些时间段内测量的VO进行平均，并转换为代谢当量（METs）。
所有活动的VO范围为0.18 - 3.2升/分钟（0.8 - 12.2 METs）。对于定义为<1.5 METs的最低身体活动水平，加速度计戴在优势手（120.9±8.7 gmin）与非优势手（99.9±6.8 gmin；P = 0.016）时，SVMgs存在显著差异。以6 METs作为转折点的分段线性回归模型显示，非优势手腕（r = 0.85；P < 0.001）和优势手腕（r = 0.86；P < 0.001）具有相似的显著相关性。在低于6 METs时使用非优势手腕，SVMgs与METs之间关系的斜率为105.3±4.3（95% CI 96.9至113.7），表明摄氧量每增加1 MET，SVMgs大约增加100个单位。
佩戴在手腕上的三轴加速度计能够可靠地预测<6 METs的常见身体活动期间的能量消耗。当加速度计戴在非优势手腕而不是优势手腕上时，发现相关性更一致。
