As coaches, one of our primary objectives in the training facility is to select and utilize exercises that have the greatest transfer or carry-over to sporting actions. Dynamic correspondence is a term used in Siff and Verkhoshansky’s classic text, “Supertraining”. This term captures the essence of the SAID principle where training must be specific enough to a given sporting movement to positively affect performance. Siff and Verkhoshansky list several criteria for an exercise to elicit carry-over to sports. This includes a common amplitude/direction of movement; accentuated region of force production; and rate and time of maximal force production, among others.
Several sporting actions are difficult to recreate in the weight room and it isn’t always a good idea to try and do this. Change of direction ability, for example, is a common and unique sporting movement in nearly all field and court sports. It is currently unclear what the best exercises are that carry over to change of direction speed. However, in a new study published ahead of print in the Journal of Strength and Conditioning Research, Delaney et al. provide a strong case for a few select exercises.
Thirty-one professional Rugby League players performed a series of performance tests at pre-season training camp. The testing included 40 m sprinting speed (with 10 m splits), 5-0-5 change of direction, 3RM back squat, drop jump, loaded counter-movement jump (40kg), and single leg lateral hop for distance. In addition to performance tests, anthropometric data were recorded. In addition to absolute values for strength and power, relative values were also included to eliminate bias and account for the variability in sizes among the players.
Via stepwise regression analyses, the authors determined that maximal linear speed and relative squat strength explained 61% of the variance in change of direction performance when assessed on the dominant leg. When assessed for the non-dominant leg, measures of mass, unilateral and bilateral power contributed 67% to change of direction performance. Ultimately, the results of the regression suggest that change of direction was heavily dependent on relative strength and power for the non-dominant leg while change of direction on the dominant leg was best predicted by linear sprint speed. The authors encourage coaches to focus on exercises that will increase an athlete’s lower body strength and power (like squats and plyometrics), while also maintaining lean muscle mass.
Reference:
Delaney, JA., et al. (2015) Contributing factors to change-of-direction ability in professional rugby league players. Journal of Strength and Conditioning Research, Ahead of print.
