Freitas João, Moreira Alexandre, Carvalho João, Conceição Filipe, Estriga Luisa
Faculty of Sport, University of Porto, 4200-450 Porto, Portugal.
COD, Centre of Sports Optimization, Sporting Clube de Portugal, 1600-464 Lisbon, Portugal.
Sensors (Basel). 2025 Apr 27;25(9):2764. doi: 10.3390/s25092764.
Accelerometer-based wearables offer a cost-effective solution for managing match and training loads in invasion team sports. However, a multitude of acceleration-derived metrics, each employing different algorithms, has led to inconsistent and incomparable outcomes across studies and devices. This article reviews the mathematical procedures underlying whole-body mechanical load metrics, clarifies their conceptual differences, and proposes refinements to enhance standardization. Synthetic data were employed to investigate conceptual differences, while experimental accelerometric data (463 time series) from a set of elite handball training sessions (involving 16 players) were used to implement the corrected equations and analyze statistical relationships. Analysis of synthetic data revealed that derivative-based metrics, such as Jerk Modulus (typically referred to as Player Load) and corrected Accel'Rate (cAccel'Rate), tend to amplify noise compared to acceleration-based metrics, such as universal Dynamic Stress Load (uDSL) and Body Load. Experimental results indicated that when metrics were summed, their values were nearly identical. In time-series comparisons, Jerk Modulus and cAccel'Rate were predictably found to be nearly identical, while Body Load was the most distinct. Acceleration-based metrics are preferable to derivative-based ones. Sports scientists should lead the design and validation of such metrics, ensuring methodological rigor, transparency, and innovation while preventing commercial interests from introducing rebranded variables with undisclosed scaling factors and unclear calculations.
基于加速度计的可穿戴设备为管理侵入性团队运动中的比赛和训练负荷提供了一种经济高效的解决方案。然而，大量基于加速度的指标，每个都采用不同的算法，导致不同研究和设备之间的结果不一致且无法比较。本文回顾了全身机械负荷指标背后的数学程序，阐明了它们的概念差异，并提出了改进措施以加强标准化。使用合成数据来研究概念差异，同时使用一组精英手球训练课程（涉及16名球员）的实验加速度计数据（463个时间序列）来实施校正后的方程并分析统计关系。合成数据分析表明，与基于加速度的指标（如通用动态应力负荷（uDSL）和身体负荷）相比，基于导数的指标，如急动模量（通常称为球员负荷）和校正加速度率（cAccel'Rate），往往会放大噪声。实验结果表明，当对指标进行求和时，它们的值几乎相同。在时间序列比较中，不出所料地发现急动模量和cAccel'Rate几乎相同，而身体负荷是最独特的。基于加速度的指标优于基于导数的指标。体育科学家应主导此类指标的设计和验证，确保方法的严谨性、透明度和创新性，同时防止商业利益引入具有未公开缩放因子和不明确计算的重新命名变量。
