Abstract
The purpose of this study was to assess the acute effect of Accentuated Eccentric Loading (AEL) on countermovement jump (CMJ) height, peak power output (PPO) and peak velocity in male professional footballers using loads of 20% or 40% of body mass (AEL20 or AEL40, respectively). Twenty-three male professional football players (age 24 ± 4.5 years, range 18–34 years; body mass 80.21 ± 8.4 kg; height 178.26 ± 7.62 cm) took part in a randomised, cross-over design to test the potentiating responses of two AEL conditions (AEL20 and AEL40) versus a body weight control group (CON). Mean loads for the two conditions were 15.84 ± 1.70 kg (AEL20) and 31.67 ± 3.40 kg (AEL40). There was no significant difference between the three conditions for jump height (p = 0.507, η2G = 0.022). There were significant differences in peak power between the groups (p = 0.001, η2G = 0.154). Post hoc analysis with Bonferroni adjustment showed significantly higher peak power for both AEL conditions compared to the control group, but no significant differences between AEL conditions (CON vs. AEL20, p = 0.029, 95% CI −1016.735, −41.815, Cohen’s d = −0.56; CON vs. AEL40, p = 0.001, 95% CI −1244.995, −270.075, Cohen’s d = −0.81; AEL20 vs. AEL40, p = 0.75, 95% CI −715.720, 259.201, Cohen’s d = −0.24). There was no significant difference between the three conditions for peak velocity (p = 0.269, η2G = 0.046). AEL using either 20% or 40% of body mass may be used to increase peak power in the countermovement jump in well-trained professional football players.
Highlights
The effective expression of muscular power is widely considered to be a key determinant in athletic performance [1,2,3,4] and is defined as being the amount of work produced per unit of time and the product of force and velocity [5,6,7]
Jumps were the third most frequent action, behind straight sprinting and rotations. Due to this shortage of the literature regarding the use of accentuated eccentric loading (AEL) as a conditioning activity within professional football, and the previous recommendation that future research should focus on the acute responses to AEL in athletic populations [24], the aim of the present study is to assess the acute effect of AEL using two different loads
The analysis showed that the increase in during the the eccentric portion ofCMJ
Summary
The effective expression of muscular power is widely considered to be a key determinant in athletic performance [1,2,3,4] and is defined as being the amount of work produced per unit of time and the product of force and velocity [5,6,7]. Developing an athlete’s ability to express peak power is a priority for many strength and conditioning coaches, both chronically over a specific training block, and acutely prior to performance. One suggested method for enhancing an acute performance prior to an activity is that of post-activation potentiation (PAP), a phenomenon whereby an acute enhancement in muscular contraction occurs following a high-intensity conditioning activity [11,12,13,14]. The specific physiological underlying mechanism of PAP is still not well-understood [11,14,15], with suggestions that any acute enhancement in muscular performance is down to the contractile history of the muscle [16] associated with an increase in phosphorylation of myosin heavy light chains increasing cross-bridge attachment rates [17,18]. Alternative suggestions have been put forward, such as an increase in muscle temperature, a change in muscle pH, and/or a change in muscle blood flow or water content [14]
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