RESISTANCE TRAINING IMPROVES RESISTANCE EXERCISES NOT BASEBALL HITTING
Szymanski, D. J., Szymanski, J. M., Bradford, T. J., Schade, R. L., & Pascoe, D. D.(2007). Effect of twelve weeks of medicine ball training on high school baseball players. Journal of Strength and Conditioning Research, 21, 894-901.
This study examined the effect of 12 weeks of medicine ball training on high school baseball players (N = 49). Players were randomly assigned using a stratified sampling technique into two groups. Group 1 (N = 24) and Group 2 (N = 25) performed the same full-body resistance exercises according to a stepwise periodized model and took 100 bat swings a day, three days per week, with their normal game bat for 12 weeks. Group 2 performed additional rotational and full-body medicine ball exercises three days per week for 12 weeks. Pre- and post-testing consisted of a three repetition maximum dominant and nondominant torso rotational strength and sequential hip-torso-arm rotational strength (medicine ball hitter's throw). A 3 RM parallel squat and bench press were measured at 0 and after 4, 8, and 12 weeks of training.
Both groups made statistically significant increases in dominant and nondominant torso rotational strength and the medicine ball hitter's throw. Group 2 showed significantly greater increases in all three variables when compared to Group 1. Furthermore, both groups made significant increases in predicted 1 RM parallel squat and bench press after 4, 8, and 12 weeks of training but there were no differences between groups.
Implication. Performing a 12-week medicine ball training program in addition to a stepwise periodized resistance training program with bat swings provided greater "sport-specific" training improvements in torso rotational and sequential hip-torso-arm rotational strength in high school baseball players.
There is a subtle unsubstantiated claim in this investigation. Both groups improved in the variables, one more than the other. There is no evidence that such improvements transferred to the skill of hitting a baseball or that the greater amount in the group that did the extra training improved with more hitting skill than the lesser-improved group of players. Such an assumption is unsubstantiated and can only be verified by controlled experimental evidence involving hitting skill, which is not provided in this study.
Another obvious weakness in the investigation is the terminology used. The authors claim the training improvements are "sport-specific". Both groups performed resistance training. Group 1 might have improved because of the resistance exercises and not used those improvements to benefit their hitting. That Group 2 improved even further with added training on non-sport-specific exercises is a simple demonstration of specific training effects, the "specific" referring to resistance training exercises and not baseball hitting. The measured changes could have been demonstrated by swimmers, polo players, and chess players were they to undertake them. Because baseball players served as Ss does not mean any improvements in independent resistance exercises assist or stem from activities associated with baseball. There is no evidence that any such assertion is logically justified.
Implications of benefit to a sport when those benefits are not demonstrated in the sport are endemic in this type of work. It is a pity that spurious assertions of the type involved in this article are commonplace in the Journal in which they were published and in the sport in general.
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