Abstract
Purpose: This study examined the inter-day reliability of a pre-determined (PDet) or a self-determined (SDet) isometric squat test (ISqT) among youth soccer players. Familiarisation effects were evaluated to determine the minimum number of trials necessary to obtain consistent outputs. Lastly, protocol differences were evaluated.
Methods: Thirty-one youth soccer players (mean ± SD: age: 13.2 ± 1.0 years; body mass: 54.1 ± 3.4 kg; stature: 166.3 ± 11.2 cm; percentage of estimated adult height: 92.6 ± 3.6%) from a top tier professional academy completed four experimental sessions for each protocol: familiarisation 1, familiarisation 2, test, and retest sessions. Peak force (PF), relative peak force (rPF), impulse from 0-50ms (IMP50), 0-100ms (IMP100), 0-150ms (IMP150), and 0-200ms (IMP200), and rate of force development from 0-50ms (RFD50), 0-100ms (RFD100), 0-150ms (RFD150), and 0-200ms (RFD200) were measured.
Results: Both protocols displayed acceptable (intraclass correlation coefficient ≥0.75 and coefficient of variation ≤10%) reliability statistics for all metrics apart from RFD of any time epoch. Differences were found between familiarisation 2 and both test and retest sessions for PF (P = 0.034 and 0.021 respectively) and rPF (P = 0.035 and 0.005 respectively) across both protocols.
Conclusions: The ISqT is a reliable test among youth soccer players. Two familiarisation sessions seem to be sufficient to ensure data stabilisation. Outputs between the SDet and PDet are comparable, however, the latter seems preferable due to improved testing time efficiency.
Methods: Thirty-one youth soccer players (mean ± SD: age: 13.2 ± 1.0 years; body mass: 54.1 ± 3.4 kg; stature: 166.3 ± 11.2 cm; percentage of estimated adult height: 92.6 ± 3.6%) from a top tier professional academy completed four experimental sessions for each protocol: familiarisation 1, familiarisation 2, test, and retest sessions. Peak force (PF), relative peak force (rPF), impulse from 0-50ms (IMP50), 0-100ms (IMP100), 0-150ms (IMP150), and 0-200ms (IMP200), and rate of force development from 0-50ms (RFD50), 0-100ms (RFD100), 0-150ms (RFD150), and 0-200ms (RFD200) were measured.
Results: Both protocols displayed acceptable (intraclass correlation coefficient ≥0.75 and coefficient of variation ≤10%) reliability statistics for all metrics apart from RFD of any time epoch. Differences were found between familiarisation 2 and both test and retest sessions for PF (P = 0.034 and 0.021 respectively) and rPF (P = 0.035 and 0.005 respectively) across both protocols.
Conclusions: The ISqT is a reliable test among youth soccer players. Two familiarisation sessions seem to be sufficient to ensure data stabilisation. Outputs between the SDet and PDet are comparable, however, the latter seems preferable due to improved testing time efficiency.
| Original language | English |
|---|---|
| Journal | International Journal of Sports Physiology and Performance |
| Publication status | Accepted/In press - 27 Mar 2023 |
Keywords
- strength
- power
- assessment
- self-determination
- autonomy
