Power absorption and production during slow, large-amplitude stretch-shorten cycle motions

Abstract

The purpose of this study was to determine the important predictors of power absorption and power production during slow, large-amplitude stretch-shorten cycle (SSC) motions. The relationship between power absorption (mean eccentric power output) and production (mean concentric power output) across different inertial loads was also investigated. Fifty-four subjects with a sporting background performed concentric (CBP) and rebound bench-presses (RBP) at 40% and 80% of their one-repetition maximum (1RM). The relationship between kinematic and kinetic variables and mean eccentric power and RBP mean power output was determined using correlation and multiple regression analysis. Maximal strength was found to be the best single predictor of power absorption, explaining between 44.2% and 69.1% of the variability that was associated with mean eccentric power output for 40% and 80% 1RM loads. Stretch velocity in combination with maximal strength was found to be the best two-predictor model of power absorption ( R(2)=83.7-97.3%). The best single predictor of SSC power production was found to be concentric mean power output ( R(2)=49.2-88.0%). The utilisation of the power absorbed during the power production phase differed across loads. It was suggested that as maximal strength is more trainable than speed, training to improve power absorption might emphasise maximal strength development. It was also suggested that SSC power output might benefit from training methods that focus on concentric force development. Further research is needed to evaluate these hypotheses and whether the findings of this study are similar for fast SSC motion.

The Impact of Velocity of Movement on Performance Factors in Resistance Exercise

“…This is explained by the higher movement speeds, which would contribute to the power output (force multiplied by velocity) during each repetition. Resistance training studies have shown that peak power improves significantly at higher velocities compared with slower velocities, even when only small differences in training velocity are examined (7,21). For instance, Fielding et al (9) showed that a self-selected fast movement velocity during the concentric portion of lower-body exercises with a 1-second hold (before performing the eccentric phase) and a 2-second eccentric phase elicited greater improvements in peak power compared with a 2-1-2 tempo (2second concentric and eccentric and 1-second isometric phase between eccentric and concentric phases of a repetition) after 16 weeks of training the leg press and knee extension exercises.…”

Longer repetition duration increases muscle activation and blood lactate response in matched resistance training protocols

“…Considering that the training protocols were matched, this result may be attributed to a longer duration of eccentric muscle action in the 2:4 protocol when compared to the 2:2 protocol. This longer duration denotes a decreased movement velocity during eccentric action, which has been linked to a decreased use of elastic energy in the stretch-shortening cycle (SSC) (Bosco, Komi, & Ito, 1981;Cronin, Mcnair, & Marshall, 2002). In addition, previous studies have shown that training protocols performed with longer duration of eccentric action caused an increase in eccentric-concentric transition time (Martins-Costa, Diniz, Machado, Lima, & Chagas, 2012;Sampson et al, 2014).…”

Blood pressure responses to resistive exercise in trained female athletes: Influence of velocity of movement

“…Fast motor units recruited during fast training velocity [11,15,18]. This type of exercise can produce higher forces after a period of training utilizing faster velocity movements involves the greater use of the stretch shortening cycle, and it has been supported that it could induce more metabolic stress and muscle sympathetic nerve charge resulting increases in SBP until 60th min of post-exercise [15,[19][20][21][22].…”