The Effects of the "Sling Shot" Device on Bench Press Performance, Mechanical Properties of Muscle, and Movement Kinematics

Abstract

Wojdała, G and Krzysztofik, M. The effects of the "sling shot" device on bench press performance, mechanical properties of muscle, and movement kinematics. J Strength Cond Res 37(4): 780-786, 2023-This study aimed to evaluate the influence of the sling shot support device at various external loads and intensities of effort, taking into account acute changes in power performance, mechanical muscle properties, and bench press kinematics. For this purpose, 12 resistance-trained men (age: 27.1 ± 4.2 years, body mass: 90.3 ± 16.9 kg, bench press [BP] 1 repetition maximum [1RM]: 112.7 ± 23.1 kg) (resistance training experience: 6.9 ± 3.8 years) participated in the study. Each subject completed 2 experimental sessions that differed in the use of the sling shot (SS) or nonuse (CONT) of the SS and an appropriate external load. The 2 experimental sessions consisted of the 1RM test, 3 sets of 2 repetitions of BP with the load increased in each set (50-70-90% 1RM), and a fourth set of the BP efforts to muscle failure with a 70% 1RM load. Before and after each set, the changes in triceps brachii oscillation frequency and stiffness were assessed by means of myotonometry. Results indicated a significant main effect of the SS to increase peak power ( p < 0.0001, η 2 = 0.733). Furthermore, a significantly higher 1RM (129 ± 26 vs. 113 ± 23 kg, p < 0.001, effect size [ES]: 0.63), number of repetitions (15 ± 3 vs. 13 ± 2, p = 0.013, ES: 0.76), and time under tension (34 ± 10 vs. 29 ± 6 seconds, p = 0.017, ES: 0.59) were found during the set to failure for SS in comparison to the CONT condition. Moreover, there was a significant main effect of time to increase oscillation frequency ( p = 0.001; η 2 = 0.666) and stiffness ( p = 0.002; η 2 = 0.613) from pre- to postset measure. In addition, the main effect of the side ( p = 0.034; η 2 = 0.348) was reported to show higher stiffness on the dominant than on the nondominant side in the CONT condition. The results suggest that an independent 1RM measurement and a correspondingly higher workload are required to take full advantage of the SS device. Moreover, the SS can also be used successfully to increase training volume and the involvement of nondominant limbs during a bench press.