The association between prescribed and measured delivery intensity in elite male cricket fast bowlers

      Background: A common practice among sport scientists is to prescribe a targeted training load for each training session. Loads captured in training should ideally align with what was prescribed to ensure healthy adaptations. Otherwise, maladaptations to training may occur, predisposing the athlete to overreaching, burnout, illness, or injury. Most workload research in cricket fast bowling has not measured the intensity of a delivery; a key component in profiling the demand of an activity. Elite fast bowlers in Victoria have access to instantaneous feedback on their bowling speed during indoor training that may help them adhere to a prescribed delivery intensity throughout a session. Therefore, the purpose of this investigation was to determine the association between prescribed and measured delivery intensity operationalised as bowling speed.
      Methods: Six elite male fast bowlers participated in this longitudinal, repeated-measures study conducted during the cricket pre-season of 2018/19. The pre-season bowling programme comprised 14 bowling sessions over 8 weeks (total of 570 deliveries per participant). Each session was planned with a fixed bowling volume (number of deliveries) and prescribed delivery intensity (absolute bowling speed individualised to each participant). Seven prescribed absolute bowling speed thresholds (delivery intensities) were derived and used for each bowler; these were based on approximate matching of absolute ball speeds to relative peak PlayerLoadTM data at 70%, 75%, 80%, 85%, 90%, 95%, and 100% profiled in the 2017/18 season. Absolute bowling speed data was converted to a relative peak for each participant and used for statistical analysis. Mixed-effects linear regression was used to determine the association between prescribed and measured delivery intensity, while controlling for clustering of repeat trials for each participant. Statistical analyses were conducted in Stata, with statistical significance was set at p < 0.05.
      Results: There was a significant, moderate positive relationship between prescribed and measured delivery intensity (r = 0.37, p = 0.0112). Relative bowling speed was on average 11–17% higher than prescribed, across prescriptions of 70-80%. This difference was reduced to 2.5% at the prescribed delivery intensity of 90%.
      Discussion: As observed in recent studies, relative bowling speed is markedly elevated at lower prescribed delivery intensities. These findings indicate fast bowlers have difficulty in adhering to lower planned delivery intensities despite instantaneous feedback. Sessions planned at lower prescribed delivery intensities may result in larger variability in load experienced than those planned at higher intensities and contribute to unintended maladaptation’s.
      Conflict of Interest Statement: “Adrian Mott and Justin Forbes are employees of Cricket Victoria. The authors declare no other conflicts of interest.”