(49) Normative Data of Load-Velocity Relationship Variables from Isometric Mid-thigh Pull and Countermovement Jump in Elite Athletes.

In recent years, there has been popular to evaluate the dynamic strength index (DSI), which is the ratio of the peak force of the isometric mid-thigh pull (IMTP) and the peak force during countermovement jump (CMJ), as well as load-velocity profiles using CMJ with multiple loads, to be used for individualized training plans. However, there are some problems with the use of both methods because the peak force during CMJ can vary depending on the jump strategy, and creating load-velocity profiles requires high impacts at landing which are often challenging to perform with heavy loads.

Purpose: The purpose of this study was to develop normative data for elite athletes by creating a load-velocity profile using a simple two-point method based on the peak force of the IMTP (velocity = 0) and the vertical velocity of the CMJ (load = body weight).

Methods: A total of 147 international-level male athletes (age: 23.5 ± 4.4 yr, height: 1.82 ± 0.12 m, body mass: 81.3 ± 14.0 kg) from various sports domains (6 in water sports, 9 in precision sports, 5 in winter sports, 73 in ball-game sports, 37 in racket sports, 17 in combat sports) participated in the study. They performed CMJ for 2 trials and IMTP for 2 trials on two force platforms (Hawkin Dynamics Inc., Maine, USA). Peak force during IMTP and velocity at takeoff and jump height during CMJ were calculated from ground reaction force data. Load-velocity relationship variables (load-axis intercept [L0] and velocity-axis intercept [V0]) were obtained from these variables, and standardized T-scores (scaled from 0 to 100) were calculated from the mean and standard deviation.

Results: L0 (IMTP peak force) was 4.17 ± 0.57 N/body weight, CMJ height was 0.42  ±0.06 m, CMJ velocity at takeoff was 2.86 ± 0.20 m/s, V0 was 3.78 ± 0.26 m/s, and the slope (F0/V0) was -1.11 ± 0.19.

Conclusions: The normative data obtained from this study can be used as a reference for coaches and sport scientists to assess an athlete's performance and design individualized training plans. PRACTICAL APPLICATIONS: This method is simple and practical, making it a useful tool for monitoring athlete's progress and evaluating the effectiveness of training interventions.

Acknowledgements: None