Publications by authors named "Lachlan Mitchell"

Disulfide bond (Dsb) oxidoreductases involved in oxidative protein folding govern bacterial survival and virulence. Over the past decade, oligomerization has emerged as a potential factor that dictates oxidoreductase activities. To investigate the role of oligomerization, we studied three Dsb-like ScsC oxidoreductases involved in copper resistance: the monomeric StScsC, and the trimeric PmScsC and CcScsC.

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Multidisciplinary sports like triathlons require combining training for three different sports, and it is unclear how triathlon coaches manage this. During a 10-week period, we provided four age-group triathlon coaches with summary reports of the training completed by their athletes (n = 10) in the previous week. Coaches were then asked if the information provided to them was used to inform training prescription for the following week.

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Sport science practitioners utilise findings from peer reviewed research to inform practice. Fewer studies are conducted with high performance athletes, however, than those involving recreationally active participants. Noting that research findings from recreational athletes may not be generalisable to the elite, there is a need to engage the latter cohort in research with better potential to influence health and performance.

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Background: Nutrition guidance for athletes must consider a range of variables to effectively support individuals in meeting energy and nutrient needs. Resistance exercise is a widely adopted training method in athlete preparation and rehabilitation and therefore is one such variable that will influence nutrition guidance. Given its prominence, the capacity to meaningfully quantify resistance exercise energy expenditure will assist practitioners and researchers in providing nutrition guidance.

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Diet, exercise and the gut microbiome are all factors recognised to be significant contributors to cardiometabolic health. However, diet and exercise interventions to modify the gut microbiota to improve health are limited by poor understanding of the interactions between them. In this pilot study, we explored diet-exercise-microbiome dynamics in bodybuilders as they represent a distinctive group that typically employ well-defined dietary strategies and exercise regimes to alter their body composition.

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Inter-individual differences in maturation-associated development can lead to variations in physical performance, resulting in performance (dis)advantages and maturation selection bias within youth sport systems. To address such bias and account for maturational differences, Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could be beneficial. The present study aimed to: (1) determine maturity timing distributions in youth female swimming; (2) quantify the relationship between maturation status and 100-m front-crawl (FC) performance; (3) implement Mat-CAPs to remove maturational influences upon swimming performance.

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Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res 36(8): 2176-2185, 2022-This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise.

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Severe-intensity constant work rate (CWR) cycling tests simulate the high-intensity competition environment and are useful for monitoring training progression and adaptation, yet impose significant physiological and psychological strain, require substantial recovery, and may disrupt athlete training or competition preparation. A brief, minimally fatiguing test providing comparable information is desirable. Purpose To determine whether physiological variables measured during, and functional decline in maximal power output immediately after, a 2-min CWR test can act as a proxy for 4-min test outcomes.

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Dietary intake plays a significant role in athletic performance and is influenced by several factors, including nutrition knowledge. Gaelic footballers are amateur athletes who conduct high-intensity, intermittent activity during training and competition, and have previously demonstrated insufficient dietary intake. This study aimed to examine nutrition knowledge in elite and non-elite Gaelic footballers.

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Context: Optimizing nutrition in military groups through improved diet quality and nutrition knowledge is key in supporting the high physical and cognitive demands.

Objective: The objective of this investigation was to systematically review the effectiveness of nutrition interventions among military personnel in improving diet quality and/or nutrition knowledge.

Data Sources: Medline, Embase, CINAHL, and Scopus were searched from the earliest records to May 2020.

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Objectives: The global COVID-19 pandemic produced large-scale health and economic complications. Older people and those with comorbidities are particularly vulnerable to this virus, with nursing homes and long term care facilities (LTCF) experiencing significant morbidity and mortality associated with COVID-19 outbreaks. The aim of this rapid systematic review was to investigate measures implemented in LTCF to reduce transmission of COVID-19 and their effect on morbidity and mortality of residents, staff and visitors.

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To develop a statistical model of winning times for international swimming events with the aim of predicting winning time distributions and the probability of winning for the 2020 and 2024 Olympic Games. The data set included first and third place times from all individual swimming events from the Olympics and World Championships from 1990 to 2019. We compared different model formulations fitted with Bayesian inference to obtain predictive distributions; comparisons were based on mean percentage error in out-of-sample predictions of Olympics and World Championships winning swim times from 2011 to 2019.

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To meet the need for regular and reliable data on the prevalence of overweight and obesity among children in Europe, the World Health Organization (WHO) European Childhood Obesity Surveillance Initiative (COSI) was established in 2007. The resulting robust surveillance system has improved understanding of the public health challenge of childhood overweight and obesity in the WHO European Region. For the past decade, data from COSI have helped to inform and drive policy action on nutrition and physical activity in the region.

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Aim: The aim was to predict and understand variations in swimmer performance between individual and relay events, and develop a predictive model for the 4x200-m swimming freestyle relay event to help inform team selection and strategy.

Data And Methods: Race data for 716 relay finals (4 x 200-m freestyle) from 14 international competitions between 2010-2018 were analysed. Individual 200-m freestyle season best time for the same year was located for each swimmer.

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This exploratory clinical case report presents an 87-year-old man who began bodybuilding at the age of 76 years and was officially recognised as the world's oldest competitive bodybuilder, competing until age 83. He has a background of complex health conditions including polio, strokes, cardiac arrest, atrial fibrillation, prostate disease, osteoarthritis, depression, bowel obstruction, reflux, and bladder cancer. Assessments of body composition, bone density, muscle performance, and diet-related practices were performed.

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Objectives: The purpose of this study was to document the longitudinal strength and power characteristic changes and race performance changes of a skeleton athlete.

Method: Longitudinal strength and power changes were assessed with strength and power diagnostic testing over a 9-year period. Trends over 9 years for relative strength were analyzed using a linear model.

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Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res XX(X): 000-000, 2021-This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise.

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This study aimed to 1) identify what starting block outcome kinetics have the greatest relationship to 15 m start time; 2) investigate key mechanistic determinants of the block phase and how these forces are sequenced. One hundred and fifty-two high-level competitive swimmers were included in the study. Linear mixed modelling identified four on-block outcome kinetic variables (work, average power, horizontal take-off velocity (HTOV), and average acceleration) as having a very large relationship (R = 0.

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Purpose: First, to examine whether heart rate variability (HRV) responses can be modeled effectively via the Banister impulse-response model when the session rating of perceived exertion (sRPE) alone, and in combination with subjective well-being measures, are utilized. Second, to describe seasonal HRV responses and their associations with changes in critical speed (CS) in competitive swimmers.

Methods: A total of 10 highly trained swimmers collected daily 1-minute HRV recordings, sRPE training load, and subjective well-being scores via a novel smartphone application for 15 weeks.

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Aim: Waist circumference-to-height ratio (WHt) has been proposed as an alternative measure to BMI due to its focus on central weight distribution and its basic threshold for increased cardiometabolic risk. This study aimed to compare prevalence of overweight including obesity using BMI and WHt, and assess 10-year trends of WHt prevalence, in a representative sample of Irish children.

Methods: Children measured during rounds 2-5 of the Childhood Obesity Surveillance Initiative (n = 20037) were classified as healthy weight or overweight including obesity (International Obesity Task Force age and sex BMI cut-offs), and low or high WHt (WHt ≥ 0.

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Background: A paucity of research exists concerning physiological factors influencing heart structure and function in strength athletes. This pilot study investigated whether body composition and muscle performance are associated with indices of cardiac structure and function in experienced resistance trainers.

Methods: A cross-sectional study designed was employed to address the study aim.

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Objectives: To (1) examine the association between maturity timing and performance-based selection levels in (N=708) Australian male 100-m Freestyle swimmers (12-17 years); (2) identify the relationship between maturation status and 100-m Freestyle performance; and (3) determine whether Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could remove maturation-related differences in swimming performance.

Methods: In Part 1, maturity timing category distributions ('Early', 'Early Normative', 'Late Normative' and 'Late') for 'All', 'Top 50%' and '25%' of raw swimming times were examined within and across age-groups. In Part 2, multiple regression analyses quantified the relationship between maturity offset (YPHV) and swimming performance.

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Objectives: The aims of this cross-sectional study were to describe the client experiences of registered exercise professionals (REP) in regard to nutrition advice, and to identify factors considered important when selecting a REP.

Design: A convenience sample of fitness facility-users were recruited. Participants completed a 46 item online questionnaire.

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Nutrition education programmes for athletes aim to enhance nutrition knowledge and more importantly support positive dietary change to enhance performance, health and well-being. This systematic review assessed changes in the dietary intakes of athletes in response to nutrition education programmes. A search was conducted which included studies providing quantitative dietary intake assessment of athletes of any calibre aged between 12 and 65 years in response to a nutrition education programme.

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Longitudinal research on training and dietary practices of natural powerlifters is limited. This study investigated the effect of phases of training on physical and physiological parameters in male natural powerlifters. Nine participants completed testing at two time points: (i) preparatory phase (~3 months prior to a major competition) and (ii) competition phase (1-2 weeks from a major competition).

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