The Kinetic Specificity of Plyometric Training: Verbal Cues Revisited

Abstract

Plyometric training is a popular method utilized by strength and conditioning professionals to improve aspects of functional strength. The purpose of this study was to explore the influence of extrinsic verbal cueing on the specificity of jumping movements. Thirteen participants (age: 23.4 ± 1.9 yr, body height: 170.3 ± 15.1 cm, body mass: 70.3 ± 23.8 kg,) performed four types of jumps: a depth jump “as quickly as possible” (DJT), a depth jump “as high as possible” (DJH), a countermovement jump (CMJ), and a squat jump (SJ). Dependent measures, which included measurement of strength and power, were acquired using a force platform. From the results, differences in body-weight normalized peak force (BW) (DJH: 4.3, DJT: 5.6, CMJ: 2.5, SJ: 2.2), time in upward propulsion (s) (DJH: 0.34, DJT: 0.20, CMJ: 0.40, SJ: 0.51), and mean acceleration (m·s-2) (DJH: 26.7, DJT: 36.2, CMJ: 19.8, SJ: 17.3) were observed across all comparisons (p = 0.001 – 0.033). Differences in the body-weight normalized propulsive impulse (BW·s) (DJH: 0.55, DJT: 0.52, CMJ: 0.39, SJ: 0.39) and propulsive power (kW) (DJH: 13.7, DJT: 16.5, CMJ: 11.5, SJ: 12.1) were observed across all comparisons (p = 0.001 – 0.050) except between the CMJ and SJ (p = 0.128 – 0.929). The results highlight key kinetic differences influencing the specificity of plyometric movements and suggest that verbal cues may be used to emphasize the development of reactive strength (e.g. DJT) or high-velocity concentric power (e.g. DJH).

Kinetic Responses to External Cues Are Specific to Both the Type of Cue and Type of Exercise in Adolescent Athletes

“…Given the results for the CMJ and DJ, the use of force and velocity cues seems to have greater effects on movements involving the SSC. Previous literature agrees that adopting an external focus results in greater CMJ and DJ performance compared with using an internal or neutral focus (11,17,42,43), with DJ performance also being influenced by the specificity of a cue (24,31,32,44). The results from the current investigation indicate that a velocity cue provided some desirable changes during a CMJ and DJ, which could reflect enhanced SSC function (33).…”

“…However, this study has provided novel insight regarding how performance and kinetic outcomes change in adolescent athletes performing several different tasks with different external cues. This adds to previous similar research in child (i.e., 12 years or younger) athletes (32) and nonathletes (6,35) and adult moderately trained (11,13,17,31,44) and physically active populations (24,42,43).…”

“…By contrast, "reach high for the ceiling," while also an external cue, would theoretically be a more force-specific cue and may elicit greater changes in force-related variables than velocity-related and time-related variables (1). The literature supports that the specificity of a cue may result in specific outcomes in both adult and young populations (24,31,32,44). In adult and youth literature, it has been shown that using a force cue to maximize jump height increased jump performance, whereas a velocity cue to minimize contact time results in shorter ground contact times (24,31,32,44).…”

Effect of drop jump technique on the reactive strength index

“…Based on the differences recorded for the variables that describe CDJs and BDJs, it can be concluded that the study participants performed both types of jumps effectively. Therefore, it may be stated that the technique of the DJ is affected by the instruction to perform the exercise (Young et al, 1995; Jidovtseff et al, 2014; Khuu et al, 2015; Louder et al, 2015). …”

The Physiological Demands of Youth Artistic Gymnastics: Applications to Strength and Conditioning

“…Drop jumps are a highly complex task for young athletes to develop proficiency in (6), however importantly, they are primarily used as a training tool to target fast or slow SSC function through progressive overload. Cueing shorter contact times during drop jumps typically encourages faster SSC activity, while cueing athletes to prioritise maximimum jump height may result in slower SSC actions (65). An increase in leg stiffness may result in reduced ground contact times, leading to a more efficient utilization of the SSC (1,55).…”