The Effect Of Warm-up With Different Weighted-balls On Exercise Performance In Elite Teenage Baseball Players

PURPOSE: Is it true or a misconception that using heavier weighted-balls leads to greater exercise performance gains? This study aimed to investigate whether incorporating different weighted-balls during warm-up enhances exercise performance. METHODS: This study was a randomized crossover study. Twenty-four elite teenage baseball players were recruited and received four different weighted-balls (5 oz, 7 oz, 9 oz, 11 oz). The interval between each trial was set at two days. Prior to each trial, participants underwent the glenohumeral joint range of motion (ROM) and the upper quarter Y-balance test (YBT) as dynamic balance, maximal fastball speed as pretests. Subsequently, they used the weighted-ball for warm-up, and posttests were conducted by an athletic trainer. Two-way repeated ANOVA, effect size (d), and reliability were statically analyzed. RESULTS: Regarding ROM, each weighted-balls increased shoulder ROM. Among conditions, the 7 oz condition had significant effectively improvements in shoulder external rotation (p < 0.001, d = 0.59), internal rotation (p < 0.001, d = 0.84), total rotational ROM (p = 0.009, d = 1.75) and YBT (p = 0.005, d = 0.81). However, ball speed was no statistically significant between groups. DISCUSSION & CONCLUSION: While the weighted-ball proved effective in enhancing shoulder ROM and stability (in particularly, 7 oz) in the short term. However, this strategy did not result in an increase in pitching ball speed. This information offers valuable insights for coaches and athletic trainers, as they plan warm-up strategies. The long-term effects and injury prevalence of this warm-up approach warrant further investigation.NSTC 112-2410-H-037-017, MOST 111-2813-C-037-024-H