Time Course of Neuromuscular, Hormonal, and Perceptual Responses Following Moderate- and High-Load Resistance Priming Exercise

Abstract

Purpose: The aim of this study was to map responses over 32 hours following high-load (HL) and moderate-load (ML) half-squat priming. Methods: Fifteen participants completed control, HL (87% 1RM), and ML (65% 1RM) activities in randomized, counterbalanced order. Countermovement jump (CMJ), squat jump (SJ), saliva testosterone, saliva cortisol, and perceptual measures were assessed before and 5 minutes, 8 hours, 24 hours, and 32 hours after each activity. Results are presented as percentage change from baseline and 95% confidence interval (CI). Cliff delta was used to determine threshold for group changes. Results: SJ height increased by 4.5% (CI = 2.2–6.8, Cliff delta = 0.20) 8 hours following HL. CMJ and SJ improved by 6.1% (CI = 2.1–7.8, Cliff delta = 0.27) and 6.5% (CI = 1.2–11.8, Cliff delta = 0.30), respectively, 32 hours after ML. No clear diurnal changes in CMJ or SJ occurred 8 hours following control; however, increases of 3.9% (CI = 2.9–9.2, Cliff delta = 0.26) and 4.5% (CI = 0.9–8.1, Cliff delta = 0.24), respectively, were observed after 32 hours. Although diurnal changes in saliva hormone concentration occurred (Cliff delta = 0.37–0.92), the influence of priming was unclear. Perceived “physical feeling” was greater 8 hours following HL (Cliff delta = 0.36) and 32 hours after ML and control (Cliff delta = 0.17–0.34). Conclusions: HL priming in the morning may result in small improvements in jump output and psychophysiological state in the afternoon. Similar improvements were observed in the afternoon the day after ML priming.

Effects of Resistance Priming Exercise on Within-day Jumping Performance and its Relationship with Strength Level

“…jumping strategy (Table 3). To our knowledge, only a handful of studies have evaluated different vertical jump metrics after velocity-based resistance priming exercises [7,10,26].…”

“…Previous research has explored different set configurations and recovery times between the end of the priming exercise and the time of evaluation, with disparate responses observed [4][5][6][7]10].…”

“…For example, Harrison et al, [10] observed that low-volume squat-based priming exercise with a moderate load (65%1RM) increased countermovement jump height (CMJ) by 6.1%, 8 hours afterwards. Similarly, high load (67-87%1RM) priming also resulted in a 4.5% increase in squat jump height at 8 hours with a positive improvement in perceived "physical feeling" [10].…”

“…For example, Harrison et al [10] observed that low-volume squat-based priming exercise with a moderate load (65 % 1RM) increased countermovement jump height (CMJ) by 6.1 % 8 hours afterwards. Similarly, high load (67-87 % 1RM) priming also resulted in a 4.5 % increase in squat jump height at 8 hours with a positive improvement in perceived "physical feeling" [10]. Additionally, Cook et al [6] observed that back squat and bench press priming with higher training volume (12 sets) and performed to muscle failure increased CMJ peak power output in rugby union players.…”

“…While the application of long-term resistance training has been shown to improve athletic performance [1,2], an opportunity to transiently improve performance with resistance exercises also exists [3]. These conditioning activities, termed 'priming' resistance exercise(s), are usually performed on the same day [4][5][6][7][8] or the day before [6][7][8][9][10][11] a competition/task in an attempt to produce a transient increase in performance in the next 2-48 h. Some of the physio logical mechanisms that have been suggested to be involved in these changes in performance have been the potential to activate high frequency motor neurons, increases in muscle temperature, increases in mechanical stiffness [12], increased fiber sensitivity to calcium ions [13], and/or changes in the daily concentration of testosterone and cortisol after exercise [6]. Currently, there is no clear consensus on the conditioning activities that maximize the priming response.…”