Preprint / Version 1

Reliability of a maximum effort inertia flywheel squat protocol


  • Keegan Hall University of South Australia
  • Robert G. Crowther University of South Australia
  • Hunter Bennett University of South Australia
  • Maarten A. Immink Flinders University
  • David T. Martin Australian Catholic University



eccentric overload, Resistance training


The purpose of this study was to determine the inter-day test-retest reliability of a multi-repetition maximum effort inertia flywheel (IFw) squat test, and to identify the association between maximal performance in an IFw squat test and a 6-repetition maximum (RM) back-squat. Twelve subjects completed three sessions of squat testing: one session to determine back-squat 6RM and two sessions on the IFw. Reflective markers were attached to landmarks of the lower body to calculate repetition velocity, and the activation of lower body musculature was captured with eight electromyography (EMG) electrodes. IFw squat test load and velocity variables showed moderate-excellent test-retest reliability (ICC = 0.69 – 0.95). EMG variables between the two IFw sessions showed a negative poor-moderate positive reliability (ICC = -0.27 – 0.66). Significance for all statistical testing was set at p < 0.05. There was no significant association for maximal loads between the two testing modalities (IFw vs. 6RM; p = 0.137 – 0.192), however a significant relationship was identified between back-squat 6RM load and IFw in mean concentric velocity in session 2 (p = 0.011, r = 0.705) and final repetition velocity in both IFw sessions (p = 0.023, r = 0.648 vs p = 0.026, r = 0.635). The IFw squat test showed moderate-excellent reliability. The poor correlations between IFw and back-squat 6RM performance variables indicate that IFw specific performance tests should be used to guide IFw load prescription in training settings.


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