Examining Countermovement Jump Performance and Dynamic Balance Among Male High School Athletes With Varying Levels of Sports Specialization.

VanZile, AW, Jones, DD, McHugh, LJ, Clickovich, GL, Morales, MA, Reimschisel, RK, Widenhoefer, TL, Baughman, JT, Urquidi, MD, Conner, DJ, Dobbs, WC, Jagim, AR, Luedke, JA, and Almonroeder, TG. Examining countermovement jump performance and dynamic balance among male high school athletes with varying levels of sports specialization. J Strength Cond Res XX(X): 000-000, 2025-Specializing at a young age may limit an athlete's motor development, since focusing on a single sport potentially exposes athletes to less variety of movements and neuromuscular demands. However, there are few studies examining the association between sport specialization and movement performance/control. The purpose of this study was to compare countermovement jump performance and dynamic balance among high school athletes of varying levels of sports specialization. 110 male high school athletes completed countermovement jump testing and the Y-Balance Test (YBT). Ground reaction forces were recorded during countermovement jumps and used to derive peak force, peak velocity, peak power, jump height, and the modified reactive strength index. Y-Balance Test composite scores were calculated to assess dynamic balance across multiple directions, for the dominant and non-dominant limbs. Athletes were grouped into high (n = 46), moderate (n = 39), and low (n = 25) specialization groups based on their sport participation habits. There were no between-group differences for any of the countermovement jump metrics (p > 0.05). For the YBT composite scores, there was not a group-by-limb interaction effect (p = 0.28); however, there was a main effect of group (p = 0.03). Post hoc tests indicated that the high specialization group exhibited lower YBT composite scores compared to the moderate specialization group (p = 0.01) and a trend toward lower scores compared to the low specialization group (p = 0.05). In general, highly specialized male athletes exhibited poorer dynamic balance compared to less specialized athletes.