Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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Start date: 2020Has files: No

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    The Effect of Ammonia Inhalants on Mental-Fatigue-Related Force Loss
    (MDPI (Basel, Switzerland), 2025-12-01) Barnes MJ; O’Connor E; van Zanten J
    Objectives: Ammonia inhalants (AIs) are commonly used in competition with the assumption that they will increase arousal and reduce the detrimental effects of mental fatigue on performance. However, as the effect of AIs on mental fatigue is unclear, this study investigated (1) whether mental-fatigue-related changes in mood states are associated with reductions in maximal lower-body force production and (2) whether AIs reduce any mental-fatigue-induced changes in performance. Methods: In a randomized, crossover designed study, nine resistance trained males completed two trials, with and without AIs. Profile of mood states, isometric midthigh pull force, and electromyography were measured before and after completion of a 75 min AX-continuous performance test (AX-CPT). For AI trials, AIs were used prior to post-AX-CPT IMTPs. Results: The AX-CPT significantly increased all negative mood subscales, while decreasing vigor (all p < 0.05), resulting in an increase in total mood disturbance (pre-AX-CPT: 27.1 ± 3.17 vs. post-AX-CPT: 64.49 ± 4.01; p = 0.005). Additionally, compared to baseline, force was reduced immediately (1699 ± 345 vs. 1521 ± 324 N; p = 0.009), but not five minutes post-AX-CPT (p = 0.328). Electromyography did not change over time, and no differences between treatments were evident for any of the measures. Conclusions: Mental fatigue, and related mood disturbance, has the potential to acutely reduce lower-body, maximal force. This finding may have implications for athletes competing in strength sports where mental focus, arousal and maximal force production determine optimal performance. However, AIs offer no benefit to alleviating the detrimental effects of mental fatigue.
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    Effects of acute caffeine intake on muscular power during resistance exercise: a systematic review and meta-analysis
    (Frontiers Media S.A., 2025-10-07) Barnes M
    Background: This study examined the effects of caffeine on movement velocity and power output during resistance exercises and explored moderating factors influencing these effects. Methods: A systematic search of five databases was conducted through June 2025. A random-effects model was used to assess the effect of caffeine on muscular power-related variables, such as bar velocity and power output, during resistance exercises with a fixed number of repetitions. Subgroup analyses were performed based on sex, caffeine dose, habitual caffeine consumption, muscle group, and load. Results: Twelve studies comprising 230 participants were included. Caffeine significantly improved mean velocity (SMD = 0.42, 95% CI: 0.19–0.65, p < 0.05, I2 = 85%) and mean power output (SMD = 0.21, 95% CI: 0.12–0.30, p < 0.05, I2 = 14%) during resistance exercises. Greater improvements in mean velocity were observed in males (SMD: 0.56 vs. 0.22), and habitual caffeine consumption < 3 mg/kg/day (SMD: 0.87 vs. 0.21) (all p < 0.01 for subgroup comparisons). Furthermore, although caffeine increased mean velocity at all caffeine doses (SMD: 0.31–0.78), muscle groups (SMD: 0.32–0.54) and loads (SMD: 0.37–0.49) (all p < 0.01), no significant differences were observed between subgroups (all p > 0.01 for subgroup comparison). Conclusion: Caffeine ingestion enhances movement velocity and power output during resistance exercises, regardless of load. These benefits were more pronounced in males, at higher caffeine doses, among low habitual caffeine consumers, and during lower-body exercises.
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    Employee Experiences and Productivity in Flexible Work Arrangements: A Job Demands–Resources Model Analysis from New Zealand
    (MDPI (Basel, Switzerland), 2025-09-06) Crooney L; Tootell B; Scott J
    Purpose: This study investigates the relationship between flexible working arrangements (FWAs), employee experiences (EEs), and perceived productivity (PP) in the context of New Zealand employees. The study aims to understand how opportunities and challenges within FWAs impact employee productivity, utilising the Job Demands–Resources (JD-R) model as a theoretical framework. Design/methodology/approach: A survey was conducted with 176 employees who transitioned from traditional office settings to FWAs. Data were collected using a structured questionnaire measuring work demand, autonomy, employee experiences, and perceived productivity. The analysis involved correlational and moderated regression techniques to assess the relationships between the variables. Findings: The study found that positive employee experiences (expressed as opportunities) are significantly associated with higher perceived productivity (r = 0.610, p < 0.001), while negative experiences (expressed as challenges) are associated with lower perceived productivity (r = 0.515, p < 0.001). Moreover, management strategies were found to moderate these relationships, further influencing perceived productivity. Originality: This research contributes to the understanding of how FWAs, when effectively managed, can enhance employee productivity by fostering positive experiences. It also highlights the importance of addressing challenges to mitigate negative impacts on productivity. The use of the JD-R model offers a novel approach to exploring these dynamics in the context of FWAs. Practical and social implications: Organisations can enhance productivity by focusing on management strategies that amplify positive employee experiences and reduce challenges within FWAs. Effective FWAs can improve work–life balance, employee wellbeing, and organisational commitment, contributing to a more satisfied and productive workforce.
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    Health system resilience in the Pacific: A scoping review of Fiji’s COVID-19 response
    (Elsevier Ltd, 2025-12-01) Thomas-Maude J; McLennan S
    In mid-2021, Fiji recorded one of the highest rates of COVID-19-related deaths in the world, amidst a rapidly disintegrating health care system. This scoping review examines Fijian health system responses to the COVID-19 pandemic, exploring both the vulnerabilities and adaptive strategies that emerged during the crisis. Using a systematic search strategy to identify studies relating to how the Fijian health system responded to the COVID-19 pandemic, and what insights could be drawn about adaptive practices and resilience in this context, 71 papers were included. The findings demonstrate that while Fiji experienced significant workforce shortages, infrastructure constraints, and disruptions to routine healthcare, the pandemic response was also characterised by rapid policy adaptations, innovative use of some digital technologies, and strong community-led initiatives. However, challenges with public trust and culturally inclusive governance remain key areas for consideration. By applying a health system resilience framework that explores the tangible and intangible dimensions of health systems, this review offers insights relevant both for Fiji and the region. Strengthening local capacity, investing in sustainable infrastructure, and embedding Indigenous and other local knowledge in public health strategies are crucial steps toward building resilient Pacific health systems and preparing for future crises.
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    Effect of Caffeinated Chewing Gum on Maximal Strength, Muscular Power, and Muscle Recruitment During Bench Press and Back Squat Exercises
    (MDPI (Basel, Switzerland), 2025-07-28) Ding L; Liu J; Ma Y; Lei T-H; Barnes M; Guo L; Chen B; Cao Y; Girard O
    Background/Objectives: This study aims to investigate the effects of caffeinated chewing gum on maximal strength, muscular power, and neural drive to the prime movers during bench press and back squat in resistance-trained men. Methods: Sixteen resistance-trained males participated in a double-blind, randomized trial, chewing either caffeinated gum (4 mg/kg) or placebo gum on two separate occasions, seven days apart. After chewing for 5 min, participants performed a maximal strength test followed by muscular power assessments at 25%, 50%, 75%, and 90% of their one-repetition maximum (1RM), completing with 3, 2, 1, and 1 repetition (s), respectively, for bench press and back squat. Surface electromyography data were recorded for each repetition. Results: Caffeinated gum did not significantly improve one-repetition maximum (1RM) for bench press (p > 0.05), but increased mean frequency (MF) and median frequency (MDF) in anterior deltoid, pectoralis major, and biceps brachii (all p < 0.05) compared to placebo. For back squat, 1RM increased with caffeinated gum, along with higher MF and MDF in vastus medialis (all p < 0.05). Caffeinated gum also improved mean and peak velocities, and mean and peak power outputs at 25–75% 1RM during the bench press (all p < 0.05), along with elevated MDF in pectoralis major and biceps brachii (all p < 0.05). Similar improvements were seen in mean and peak velocities during the back squat at 25–90% 1RM (all p < 0.05), along with higher MF and MDF in vastus medialis and increased normalized root mean square activity in gluteus maximus (all p < 0.05). Conclusions: Caffeinated chewing gum (4 mg/kg) enhanced muscular power (25–75% 1RM) in the bench press and improved maximal strength and muscular power (25–90% 1RM) in the back squat by increasing muscle recruitment in resistance-trained men.
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    Re-sensing economies: Artistic and embodied knowing for more-than-capitalist futures.
    (Tampere University Press, 2025-06-01) McLean H; Mullen M; Kruglanski A; Hwang L; Dombroski K; Kangas A; Gataulina M; Poutanen M; Rajala AI; Ventovirta H-E
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    The dose-dependent effect of acute ozone exposure on lung function and the efficacy of a Boysenberry apple powder blend (BerriQi®) in reducing throat irritation and symptom recovery time in healthy adults
    (Elsevier B V, 2025-09-01) Lomiwes D; Barnes M; Nicholls G; Ngametua N; Sawyer G; Kanon AP; Vangala G; Shaw O
    Urbanization and industrialization have impacted air quality and health, with ozone exposure linked to reduced lung function and increased respiratory issues. This study characterised the dose-dependent effect of acute, controlled ambient ozone exposure in an environmental chamber on lung function, then investigated the effect of BerriQi® Boysenberry and apple powder (BerriQi) ozone-induced respiratory irritation symptoms. In an incremental dose study, healthy adults were exposed to 0.1, 0.2 or 0.3 ppm ozone for 2 h. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were measured at designated timepoints up to 48 h after ozone exposure. This was followed by a randomised, double-blind, placebo-controlled crossover trial, with healthy adults (n = 20) who consumed either BerriQi or a placebo daily for 5 days before being exposed to 0.2 ppm ozone for 2 h. Respiratory irritation symptoms, including throat irritation (TI), soreness of cough (SOC), shortness of breath (SOB), and pain on deep inspiration (PODI), were assessed at designated timepoints up to 48 h after ozone exposure. Our results showed that 0.2 ppm ozone was the maximum tolerated dose that elicited a temporal decline in lung function in healthy participants and that BerriQi supplementation significantly reduced TI (p = 0.04), and may expedite the resolution of SOC, SOB and PODI after acute ozone exposure. These findings suggest that BerriQi may alleviate the severity and duration of ozone-induced respiratory irritation and highlights the potential of BerriQi as a dietary intervention for mitigating the respiratory effects of air pollution.
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    Does Developing a Belief in One Conspiracy Theory Lead a Person to be More Likely to Believe in Others?
    (John Wiley and Sons Ltd, 2025-02-17) Williams MN; Marques MD; Kerr JR; Hill SR; Ling M; Clarke EJR
    The monological belief system model suggests that—for at least a subset of people—developing a belief in one conspiracy theory will cause them to be more likely to believe in others. This model has been influential in the literature, but its core causal hypothesis has never been credibly tested. We therefore tested it in two longitudinal studies. Study 1 used a sample from New Zealand and Australia (N = 498), with 7 monthly waves. Study 2 (preregistered) used a sample from New Zealand, Australia and the United Kingdom (N = 978), with 13 monthly waves. We applied random intercept cross-lagged panel models, permitting a credible causal identification strategy, albeit we cannot rule out time-varying confounds. We find that increased belief in a conspiracy theory at one wave did (on average) predict increased belief in other conspiracies at the next wave, although the estimated coefficients were small.
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    Sustaining the social work workforce in Aotearoa: A whole system challenge
    (Aotearoa New Zealand Association of Social Workers, 2024-12-16) O'Donoghue K