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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.
Harrison, Jenkins, Schuster, and Kelly are with the School of Human Movement and Nutrition Sciences, University of Queensland, St Lucia, QLD, Australia. Harrison is also with the Queensland Academy of Sport, Nathan, QLD, Australia. Jenkins is also with the School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia. Kelly is also with the School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, QLD, Australia. James is with the Dept of Rehabilitation, Nutrition, and Sport, School of Allied Health, La Trobe University, Bundoora, VIC, Australia. McGuigan is with the Sports Performance Research Inst New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand.