St Mary's Research Finds Mechanical Similarities Between Common Resistance Exercises

New research undertaken by St Mary’s School of Sport, Health and Applied Science has revealed the mechanical similarities between two commonly used resistance exercises to countermovement jumps. However, when intensity is raised, the mechanical similarities decline. In the study, eight physically trained men, aged around 22 years old, completed three repetitions of countermovement jumps (CMJ) followed by three repetitions at each required load for both jump squats (JS) and push jerks (PJ), after abstaining from training for 24 hours prior to the test. Kinetic and kinematic data were recorded, and a two-dimensional linked rigid segment model was used for an inverse dynamics analysis to determine hip, knee, and ankle joint moments and joint impulse. These data were then compared between each condition and load. The findings revealed a partial correspondence between the PJ and JS to the CMJ, with greatest correspondence occurring at lower relative intensities. Based on correlation analysis, similarities between lifts and CMJ decreased as load increased. Emily Cushion, a lecturer in strength and conditioning science at St Mary’s, said that these findings are particularly useful for coaches and athletes: “Coaches and athletes need to consider not only the exercise they are using but also the load that is being used. If either one of these is not quite right, then this can impact the performance gains.” The research, which was published in the Journal of Strength and Conditioning Research, also revealed how the PJ and JS can be used to improve the CMJ. The PJ was shown to relate most closely to the CMJ; therefore, this exercise will potentially increase the transfer of training effect over using the JS as a training modality for this.