Postactivation Potentiation and Change of Direction Speed in Elite Academy Rugby Players

Abstract

This study investigated the effect of preceding pro-agility sprints with maximal isometric squats to determine if postactivation potentiation (PAP) could be harnessed in change of direction speed. Sixteen elite under-17 rugby union players (age: 16 ± 0.41yrs; body mass: 88.7 ± 12.1kg, height: 1.83 ± 0.07m) from an Aviva Premiership rugby club were tested. Subjects performed a change of direction specific warm-up, followed by two baseline pro-agility tests. After 10 minutes recovery, 3 x 3-second maximal isometric squats with a 2 minute recovery between sets were completed as a conditioning activity (CA) on a force plate where peak force and mean rate of force development over 300 milliseconds were measured. The pro-agility test was repeated at set time intervals of 1, 3, 5 and 7 minutes following the CA. Overall pro-agility times were significantly slower (p < 0.05) at 1-minute post-CA compared to the baseline (3.3%), with no significant differences occurring at 3, 5 or 7 minutes post-CA. Therefore, it appears that performing multiple sets of maximal isometric squats do not enhance pro-agility performance.

Post-activation Potentiation Versus Post-activation Performance Enhancement in Humans: Historical Perspective, Underlying Mechanisms, and Current Issues

“…Importantly, in some of these studies the “standard warm-up” was not described. In other studies, however, various conditioning activities have failed to enhance athlete performance after warm-up (Sarramian et al, 2015; Marshall et al, 2019), and it is not currently clear why results vary between studies. In order to determine whether additional conditioning activities might provide a unique stimulus to the neuromuscular system, i.e., in addition to the continuation or prolongation of the prior (i.e., standard) warm-up, (1) muscle temperature and other physiological measures can be taken, and (2) the “unique” conditioning activity can be compared to one or more other conditioning activities that provide the opportunity for further temperature increase or task-specific practice but are dissimilar to the conditioning activity to be tested (see study design considerations above).…”

“…A recent study highlighted the impact of some of these points (Cuenca-Fernandez et al, 2017), with the authors observing increases in squat jump height after a non-exercising (i.e., no conditioning activity) control condition, which might indicate a PAP/PAPE effect but could also be attributed to a warm-up (temperature) effect caused by the completion of the baseline tests. In addition, a learning effect inherent to the warm-up may also have also played a key role (Marshall et al, 2019); unfortunately, control conditions (where subjects do not complete the conditioning activities but move immediately to the testing phase) are not always included, so changes in performance cannot always be ascribed to the conditioning activity. Alternatively, torque produced during an MVC might serve as a control condition to exclude some effects of a warm-up, including increases in muscle activation (Nuzzo et al, 2016) or temperature (Bergh and Ekblom, 1979), although increases in peak isometric force might not be particularly temperature sensitive (Rall and Woledge, 1990).…”

“…Thus, it remains unclear whether the conditioning activities would elicit a meaningful performance enhancement in applied settings where participants would normally complete a comprehensive, task-specific warm-up (pre-exercise preparation) period. This is particularly relevant given that some studies show no PAPE effect in athletes when a test-specific, progressive warm-up is provided (Marshall et al, 2019). In order to assess the potential practical effects of conditioning activities in applied exercise, rehabilitation or sports contexts (i.e., to obtain external validity), therefore, a complete warm-up with task-specific practice should be performed prior to the conditioning activity.…”

Unilateral Isometric Squat: Test Reliability, Interlimb Asymmetries, and Relationships With Limb Dominance

“…PF was defined as the maximum force generated during the test. RFD was defined as the rate of change in force (epoch) after the first meaningful onset was recorded at the start of each specified time point (30); while impulse was defined as the net force multiplied by the time taken to produce it at each specified time point; i.e., the area under the force-time curve (14). Limb dominance was defined as the limb with the greatest score between the two and subsequently used in this way for the calculation of inter-limb asymmetries.…”

Motor cortical and corticospinal function differ during an isometric squat compared with isometric knee extension

“…Participants held the barbell during contractions and were given freedom to choose their hand position, which was maintained throughout the trial. During contractions, participants were instructed to exert force upwards against the bar using their whole body (Bishop et al, 2017…”