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Purpose: To evaluate the test–retest reliability of isokinetic leg-press power–force–velocity profile (P–F–v) parameters in male and female elite athletes. In addition, we determined the concurrent validity of leg-press against squat-jump (SJ) P–F–v parameters in task-experienced athletes. Methods: For test–retest reliability, 22 female and 23 male elite athletes (22.3 [4.1] y) with different sporting backgrounds conducted 3 isokinetic leg-press test sessions over 3 consecutive weeks. The testing consisted of bilateral leg extensions at isokinetic velocities of 0.1, 0.3, 0.7, and 1.2 m·s−1. For concurrent validity, 13 ski jumpers (20.3 [3.3] y) were recruited to perform the isokinetic leg-press and SJ P–F–v profile tests using 5 predefined loading conditions of 0%, +20%, +40%, +60%, and +80% of body mass. Results: Relative and absolute reliability were acceptable for female (intraclass correlation coefficient ≥.87 and coefficient of variation ≤6.5%) and male (intraclass correlation coefficient ≥.89 and coefficient of variation ≤5.7%) elite athletes. In contrast, concurrent validity was insufficient, with correlations ranging from −.26 to .69 between isokinetic and SJ P–F–v parameters. Conclusion: Irrespective of sex, isokinetic leg-press P–F–v profiles provide reliable parameters. However, leg-press P–F–v profiles do not serve as a valid substitute for SJ P–F–v profiles. P–F–v parameter magnitudes are likely dependent on the constraints of the tested movement and testing device.
Fessl (email@example.com) is corresponding author, https://orcid.org/0000-0001-5892-5127