Effects of loading on maximum vertical jumps: Selective effects of weight and inertia

Abstract

A novel loading method was applied to explore selective effects of externally added weight (W), weight and inertia (W+I), and inertia (I) on maximum counter-movement jumps (CMJ) performed with arm swing. Externally applied extended rubber bands and/or loaded vest added W, W+I, and I corresponding to 10–40% of subjects' body mass. As expected, an increase in magnitude of all types of load was associated with an increase in ground reaction forces (GRF), as well as with a decrease in both the jumping performance and power output. However, of more importance could be that discernible differences among the effects of W, W+I, and I were recorded despite a relatively narrow loading range. In particular, an increase in W was associated with the minimal changes in movement kinematic pattern and smallest reduction of jumping performance, while also allowing for the highest power output. Conversely, W+I was associated with the highest ground reaction forces. Finally, the lowest maxima of GRF and power were associated with I. Although further research is apparently needed, the obtained finding could be of potential importance not only for understanding fundamental properties of the neuromuscular system, but also for optimization of loading in standard athletic training and rehabilitation procedures.

Force–velocity relationship of leg extensors obtained from loaded and unloaded vertical jumps

“…In line with both the participants' reports and our recent studies performed according to a similar procedure (Pazin et al 2013; Markovic and Jaric 2007b; Leontijevic et al 2012), fatigue was never an issue. Subjects were also instructed to avoid any strenuous exercise over the course of study.…”

“…Therefore, it remains possible that a more typical protocol that includes a higher number of trials and select the best one for analysis would provide even higher reliability and concurrent validity than we observed. Third, note that we only applied a constant loading force that mimics added weight, but not inertia, which could have markedly different effects on the force and power output in both vertical jumps and bench press throws (Leontijevic et al 2012; Leontijevic et al 2013). Fourth, we could not control for the possible effect the depth of countermovement that has been shown to affect both F and P of loaded vertical jumps (Samozino et al 2012; Markovic et al 2013).…”

“…The bands were attached at the lateral sides of a belt that was fixed approximately at the subject's waist and stretched over a system of low-friction and low-inertia plastic wheels. Therefore, the loading method allowed for unconstrained vertical jumps, while the relative change in their stretched length over the course of the tested jumps was only up 4%, yielding a similar maximum change in the loading force [for detailed description see (Pazin et al 2011; Leontijevic et al 2012)].…”

Effect of body mass and midsole hardness on kinetic and perceptual variables during basketball landing manoeuvres

“…This study attempted to determine the effect of body mass by recruiting two groups of participants with a mean body mass difference of approximately 30%. Previous studies investigating the effect of additional mass on VGRF variables during various jumping-related activities have utilised either an external load (5-10%, Makaruk & Sacewicz, 2011) or a pulley system (10-40%, Leontijevic et al, 2012) to vary the total mass. Markovic and Jaric (2007) proposed a maximum dynamic hypothesis, which suggested that the muscular system of the lower limbs is designed to optimise dynamic output when loaded with an individual's own weight.…”

The effects of coconut oil supplementation on the body composition and lipid profile of rats submitted to physical exercise

“…Among the physical exercise programs, the vertical jumping training seems to be the most complete plyometric exercise, once during its execution it is used the major muscular groups, mainly the lower limbs muscles (Markovic 2007, Leontijevic et al 2012, Lamas et al 2012. Moreover, there are no specifi c data about lipid prolife determinations and vertical jumping training.…”