McNamara Dean J, Gabbett Tim J, Chapman Paul, Naughton Geraldine, Farhart Patrick
School of Exercise Science, Australian Catholic University, Brisbane, QLD, Australia.
Int J Sports Physiol Perform. 2015 Nov;10(8):1009-14. doi: 10.1123/ijspp.2014-0497. Epub 2015 Mar 10.
The use of wearable microtechnology to monitor the external load of fast bowling is challenged by the inherent variability of bowling techniques between bowlers. This study assessed the between-bowlers variability in PlayerLoad, bowling velocity, and performance execution across repeated bowling spells.
Seven national-level fast bowlers completed two 6-over bowling spells at a batter during a competitive training session. Key dependent variables were PlayerLoad calculated with a MinimaxX microtechnology unit, ball velocity, and bowling execution based on a predetermined bowling strategy for each ball bowled. The between-bowlers coefficient of variation (CV), repeated-measures ANOVA, and smallest worthwhile change were calculated over the 2 repeated 6-over bowling spells and explored across 12-over, 6-over, and 3-over bowling segments.
From the sum of 6 consecutive balls, the between-bowlers CV for relative peak PlayerLoad was 1.2% over the 12-over bowling spell (P = .15). During this 12-over period, bowling-execution (P = .43) scores and ball-velocity (P = .31) CVs were calculated as 46.0% and 0.4%, respectively.
PlayerLoad was found to be stable across the repeated bowling spells in the fast-bowling cohort. Measures of variability and change across the repeated bowling spells were consistent with the performance measure of ball velocity. The stability of PlayerLoad improved when assessed relative to the individual's peak PlayerLoad. Only bowling-execution measures were found to have high variability across the repeated bowling spells. Player- Load provides a stable measure of external workload between fast bowlers.
保龄球投球技术的固有变异性对使用可穿戴微技术监测快速投球的外部负荷提出了挑战。本研究评估了在重复投球轮次中，不同投球手之间在球员负荷、投球速度和投球表现执行方面的变异性。
七名国家级快速投球手在一次竞争性训练中，向一名击球手完成了两轮各6轮的投球。关键的因变量包括使用MinimaxX微技术单元计算的球员负荷、球速，以及根据每投出一球的预定投球策略得出的投球执行情况。计算了两轮重复的6轮投球过程中不同投球手之间的变异系数（CV）、重复测量方差分析和最小有意义变化，并在12轮、6轮和3轮投球段进行了探索。
在12轮投球过程中，从连续6个球的总和来看，不同投球手之间相对峰值球员负荷的CV为1.2%（P = 0.15）。在这12轮期间，投球执行得分（P = 0.43）和球速CV（P = 0.31）分别计算为46.0%和0.4%。
在快速投球群体中，发现球员负荷在重复投球轮次中是稳定的。重复投球轮次中的变异性和变化测量结果与球速的表现测量结果一致。相对于个体的峰值球员负荷进行评估时，球员负荷的稳定性有所提高。仅发现投球执行测量在重复投球轮次中有较高的变异性。球员负荷为快速投球手之间的外部工作量提供了一个稳定的测量指标。
