Purpose: To evaluate cohort-specific reliability and concurrent validity of 3 different vertical power–force–velocity (P–F–v) profiles to determine force, velocity, maximal power, and the slope of the force–velocity relationship using squat jumps. Methods: Fifteen male sport students and 15 elite ski jumping athletes (male = 11; female = 4) conducted 2 block-randomized test–retest sessions with 5-point-method or 2-point-method loading conditions. A third P–F–v profile was established by excluding the data point most declining the coefficient of determination (r2) of the 5-point method. Results: Acceptable absolute and relative reliability were found across methods in ski jumping athletes (intraclass correlation coefficient [ICC] ≥ .79, coefficient of variation [CV] ≤ 6.2%). However, force values were significantly lower in the retest (≤2.1%, d ≤ 0.75). In contrast, no systematic differences (P ≥ .461), but unacceptable absolute and relative reliability, were found in sport students (ICC ≥ .63, CV ≤ 14.8%). The P–F–v parameters of the different collecting and evaluating approaches yielded high to excellent correlations (ski jumping athletes: r ≥ .64; sport students: r ≥ .61), but maximal power (≤4.6%) and velocity (<6.2%,) values of sport students revealed significant differences. Conclusion: The similarity of P–F–v testing and basic ski jumping training daily exercises seems to be more significant to obtain reliable force–velocity parameters than the methodological approach. Accordingly, P–F–v profiles seem to be reliable with the proposed methods only in highly task-experienced athletes but not in less task-experienced cohorts like sport students.

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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.

This study aimed to investigate the effect of additional loads and sex on countermovement jump (CMJ) joint kinetics during the entire take-off impulse in males and females. Twelve female and 13 male sport students performed vertical countermovement jumps without and with additional loads up to +80% of body mass using a straight barbell. Ground reaction forces and body kinematics were collected simultaneously. A significant increase was found for peak ankle power, whereas knee and hip peak power decreased significantly as additional load increased in both males and females. Joint work increased in each joint as additional load increased, although significance was observed only in the hip joint. Peak power of each joint (22–47%) and total hip work (61%) were significantly higher for males than females. Relative joint contributions to total joint work (“joint work contribution”) remained stable as additional loads increased, whereas meaningful differences were found in the magnitudes of joint work contribution between males and females. CMJ joint kinetics and joint work contributions were distinctly influenced by additional load and sex. Hence, these differences should be considered when prescribing loaded jumps for training or testing.