Performance Characteristics of National Club Baseball Association Athletes Completing In-Season Elastic Resistance Training

Purpose: The purpose of this study was to assess in-season physical performance metrics of National Club Baseball Association Athletes (NCBA) baseball players before and after a 6-week field-based elastic tubing resistance training intervention. Performance metrics included throwing velocity, isometric shoulder rotation strength, dynamic stability, muscular endurance, and range of motion (ROM). Method: A cohort of adult male NCBA athletes (n=13; 20.1±1.1years; 171.4±24.1cm; 77.0±10.5kg; all right hand dominant) enrolled in the 6-week biweekly intervention of seven upper extremity exercises. All exercises were completed with wrist-affixed elastic tubing prior to sport practices. Pre- and post-intervention testing included throwing velocity measured via pocket radar, isometric external rotation (ER) and internal rotation (IR) strength measured via handheld dynamometry (HHD), the Upper Limb Rotation Test (ULRT), Posterior Shoulder Endurance Test (PSET), and passive range of motion (PROM) for flexion, ER and IR measured via goniometer. Results: Twelve participants completed the intervention, and their data were used for pre- and post-intervention paired-sample t-test comparisons and Cohen’s dz effect size (ES) analyses. Players increased throwing side isometric ER strength at anatomical neutral shoulder position (Mean Difference, MD=25.8 N; pConclusion: Increases in rotational shoulder strength, dynamic stability, endurance, and PROM were noted post-intervention, while throwing velocity improved non-significantly. This study suggests that NCBA baseball players can enhance shoulder performance in-season with a resource-efficient resistance training program; however, additional intervention may be necessary to achieve significant gains in throwing velocity.