The Relationship Between Unilateral Press Performance And Fastball Velocity In Major League Baseball Pitchers

Fastball velocity (FV) is a primary determinant of success in Major League Baseball (MLB) pitching. Understanding which exercise motions predict higher velocity can aid in the optimization of training programs. PURPOSE: To evaluate the relationships between FV and power and acceleration in unilateral pressing motions. METHODS: We tested 28 professional MLB pitchers using a Proteus device (Proteus Motion, USA). Each pitcher performed 5 repetitions of unilateral horizontal press (12 lb) with dominant and non-dominant arms and shot put (18 lb) on the dominant arm with and without a countermovement loading phase. Peak power (W) and peak acceleration (m/s2) achieved during each repetition were recorded. Average peak values across the 5 repetitions served as predictors in simple linear regression models. The dependent variable was official MLB reports of subsequent in-game FV. RESULTS: Player age was 29.5 ± 4.1 yr, height was 192.0 ± 6.0 cm, weight was 96.7 ± 9.2 kg, and they had played 4.1 ± 3.1 seasons in the MLB. Shot put power was 401.9 ± 43.4 W and acceleration was 13.7 ± 2.9 m/s2. Including countermovement loading, shot put power was 417.6 ± 53.4 W and acceleration was 14.5 ± 4.3 m/s2. Horizontal press power was 209.7 ± 26.4 W for the dominant arm and 201.8 ± 19.6 W for non-dominant. Acceleration was 19.5 ± 7.0 m/s2 for the dominant arm and 18.3 ± 5.0 m/s2 for non-dominant. FV was 92.6 ± 2.6 mph and was related to age (β = -0.303; p = 0.010) and number of seasons played (β = -0.456; p = 0.002). Simple linear regressions found FV to be predicted by shot put acceleration (r2 = 0.147; β = 0.343; p = 0.044; 95% CI: 0.010, 0.677), shot put countermovement power (r2 = 0.182; β = 0.021; p = 0.023; 95% CI: 0.003, 0.038), shot put countermovement acceleration (r2 = 0.229; β = 0.288; p = 0.010; 95% CI: 0.075, 0.501), dominant horizontal press acceleration (r2 = 0.242; β = 0.182; p = 0.008; 95% CI: 0.052, 0.312), and non-dominant horizontal press acceleration (r2 = 0.139; β = 0.190; p = 0.051; 95% CI: -0.001, 0.381). Non-significant predictors were shot put power (p = 0.113) and horizontal press power in the dominant (p = 0.134) and non-dominant (p = 0.908) arms. CONCLUSION: Acceleration predicted FV better than power in the exercises tested. Velocity may be improved by conditioning programs that emphasize acceleration in unilateral press motions.