Jose M. Mostaffa-Viloria1, Harry P. Cintineo1, Kyle L. Sunderland1, & Patrick S. Harty1

1Lindenwood University, St. Charles, Missouri

Dynamic strength index (DSI) is an indicator showing the relationship between an athlete’s relative strength and power production capacity. This metric is calculated by dividing the peak propulsive force of an athletes’ countermovement vertical jump (CMVJ) by the peak force generated during an isometric mid-thigh pull (IMTP). The resulting ratio shows whether an athlete is relatively more strength- or power-dominant, with some researchers suggesting that scores between 0.6 – 0.8 represent athletes with a well-balanced lower-body strength and power profile. However, there have been no published studies reporting cross-sectional or longitudinal DSI data in collegiate Olympic weightlifters. PURPOSE: To characterize DSI scores and evaluate longitudinal changes in DSI and its constituent variables in collegiate Olympic weightlifters. METHODS: Male (n = 10) and female (n = 12) collegiate Olympic weightlifters performed three trials each of CMVJ and IMTP once per week during the final eight-week peaking period prior to a major national competition. All tests occurred following a 12h abstention from exercise and a standardized warmup. Mixed effects models with random intercept for subject ID were computed to identify week-to-week differences in DSI, CMVJ, and IMTP performance (α = 0.05). Cohen’s d effect sizes were calculated comparing between each week and baseline. RESULTS: Mean DSI across the entire testing period was 0.725 ± 0.133. Significant changes in CMVJ peak propulsive force (p = 0.057), IMTP peak force (p = 0.066), and DSI (p = 0.855) were not detected throughout the testing period. Effect sizes showing the magnitude of changes in IMTP and CMVJ compared to Week 1 were negligible (d < 0.10). Effect sizes were slightly larger for between-week comparisons in DSI, which decreased from baseline in Weeks 3 (d = 0.21), 5 (d = 0.19), and 7 (d = 0.22). CONCLUSION: The average DSI for collegiate Olympic weightlifters fell within the ideal range hypothesized by previous investigators (0.6 – 0.8). DSI and its component variables did not significantly change across the eight-week period, although small magnitudes of between-week change were detected. These results suggest practitioners can perform less frequent DSI tests and still capture a relevant strength and power profile of their athletes.

This document is currently not available here.