Coyne Joseph O C, Nimphius Sophia, Newton Robert U, Haff G Gregory
Int J Sports Physiol Perform. 2019 Nov 1;14(10):1447-1454. doi: 10.1123/ijspp.2018-0874.
Criticisms of the acute to chronic workload ratio (ACWR) have been that the mathematical coupling inherent in the traditional calculation of the ACWR results in a spurious correlation. The purposes of this commentary are (1) to examine how mathematical coupling causes spurious correlations and (2) to use a case study from actual monitoring data to determine how mathematical coupling affects the ACWR.
Training and competition workload (TL) data were obtained from international-level open-skill (basketball) and closed-skill (weightlifting) athletes before their respective qualifying tournaments for the 2016 Olympic Games. Correlations between acute TL, chronic TL, and the ACWR as coupled/uncoupled variations were examined. These variables were also compared using both rolling averages and exponentially weighted moving averages to account for any potential benefits of one calculation method over another.
Although there were some significant differences between coupled and uncoupled chronic TL and ACWR data, the effect sizes of these differences were almost all trivial (g = 0.04-0.21). Correlations ranged from r = .55 to .76, .17 to .53, and .88 to .99 for acute to chronic TL, acute to uncoupled chronic TL, and ACWR to uncoupled ACWR, respectively.
There may be low risk of mathematical coupling causing spurious correlations in the TL-injury-risk relationship. Varying levels of correlation seem to exist naturally between acute and chronic TL variables regardless of coupling. The trivial to small effect sizes and large to nearly perfect correlations between coupled and uncoupled AWCRs also imply that mathematical coupling may have little effect on either calculation method, if practitioners choose to apply the ACWR for TL monitoring purposes.
对急性与慢性负荷比（ACWR）的批评指出，传统ACWR计算中固有的数学耦合会导致虚假相关性。本评论的目的是：（1）研究数学耦合如何导致虚假相关性；（2）通过一个实际监测数据的案例研究来确定数学耦合如何影响ACWR。
从参加2016年奥运会各自资格赛之前的国际水平开放技能（篮球）和封闭技能（举重）运动员那里获取训练和比赛负荷（TL）数据。研究了急性TL、慢性TL以及作为耦合/非耦合变量的ACWR之间的相关性。还使用滚动平均值和指数加权移动平均值对这些变量进行了比较，以说明一种计算方法相对于另一种计算方法的任何潜在优势。
尽管耦合和非耦合的慢性TL及ACWR数据之间存在一些显著差异，但这些差异的效应大小几乎都微不足道（g = 0.04 - 0.21）。急性与慢性TL、急性与非耦合慢性TL以及ACWR与非耦合ACWR之间的相关性分别为r = 0.55至0.76、0.17至0.53以及0.88至0.99。
数学耦合在TL与损伤风险关系中导致虚假相关性的风险可能较低。无论是否耦合，急性和慢性TL变量之间似乎自然存在不同程度的相关性。耦合和非耦合ACWR之间微不足道到较小的效应大小以及大到几乎完美的相关性也意味着，如果从业者选择将ACWR用于TL监测目的，数学耦合可能对任何一种计算方法影响不大。
