Melitta A Mcnarry

• Doctor of Philosophy
• Swansea University

Background Children are more susceptible to air pollution due, at least in part, to their less-developed respiratory systems and higher respiratory rates. Although the health benefits associated with physical activity are indisputable, there is considerable debate regarding whether increased exposure to, and deeper inhalation of, air pollution whil...

Background Interest in ‘exercise snacks’ has increased, yet a comprehensive and holistic review of this novel concept is lacking. We aimed to map global research on ‘exercise snacks’, across youth, adult and clinical populations through a scoping review. Methods A systematic search was conducted in six databases. Grey literature searches were also...

Dietary supplements are widely used among individuals exposed to hot environments, but whether their consumption confers any thermoregulatory effect is unclear. Therefore, we systematically evaluated the effect of dietary supplementation on key aspects of thermoregulation (core temperature [T core ] and sweating responses) in the heat. Three databa...

Objective: This study examined acute effects of interrupting prolonged sitting with short activity breaks on postprandial glucose/insulin responses and estimations of insulin sensitivity in adults with type 1 diabetes (T1D). Method: In a randomized crossover trial, eight adults (age = 46 ± 14 years [mean ± SD], body mass index [BMI] = 27.2 ± 3.8 kg...

Purpose: To examine changes in device-based 24-hour movement behaviours (MB), and facilitators and barriers to physical activity (PA) and exercise, during remotely-delivered cardiac rehabilitation (RDCR). Materials and methods: This prospective observational study used wrist-worn GENEActiv accelerometers to assess MB of 10 service-users (63 ± 10...

Intergenerational contact offers an under-explored strategic approach to challenging age stereotypes and positively influencing health behaviors in older adults and children. It is postulated that through the application of the constructs of Contact Theory, an effective platform for change could be established. Using an instrumental case study, the...

Research pertaining to the experiences of women in rugby is scarce, which, coupled with the limited visibility of the sport and difficulty accessing resources, suggest that women’s rugby remains undervalued. Indeed, evidence of such gender inequalities remains largely anecdotal, with little rigorous research undertaken to understand the perspective...

High altitude residents have a lower incidence of type 2 diabetes mellitus (T2DM). Therefore, we examined the effect of repeated overnight normobaric hypoxic exposure on glycaemic control, appetite, gut microbiota and inflammation in adults with T2DM. Thirteen adults with T2DM [glycated haemoglobin (HbA1c): 61.1 ± 14.1 mmol mol⁻¹; aged 64.2 ± 9.4 y...

Numerous concussion-management protocols have been developed in rugby, though little is known about player’s personal experiences of concussion. Specifically, research typically refers to clinical recovery, with social and psychological sequelae post-concussion gaining little attention. This study aimed to explore the experiences of rugby players i...

Purpose To determine the effect of taurine supplementation on sweating and core temperature responses, including the transition from compensable to uncompensable heat stress, during prolonged low-intensity exercise of a fixed-heat production (~ 200W/m²) in hot conditions (37.5 °C), at both fixed and incremental vapour-pressure. Methods Fifteen fem...

Robust evidence supports the role of physical activity and exercise in increasing longevity, decreasing morbidity and helping older adults maintain the highest quality of life attainable. However, the majority of older adults are not sufficiently physically active and interventions are needed to change their behaviors. Familial or intergenerational...

Self-report and device-based measures of physical activity (PA) both have unique strengths and limitations; combining these measures should provide complementary and comprehensive insights to PA behaviours. Therefore, we aim to 1) identify PA clusters and clusters of change in PA based on self-reported daily activities and 2) assess differences in...

Cervical muscle strength has been demonstrated to reduce concussion risk in high school athletes, and interventions to improve this in male rugby players have elicited strength improvements. However, the feasibility of introducing neck‐strengthening interventions into women's rugby has not been investigated. This study sought to pilot a neck‐streng...

BACKGROUND Movement quality refers to an individual's capacity to execute movements that emulate those of an expert or adhere to pre-determined standards. Wearable technology offers a convenient and affordable means of measuring and assessing movement quality; this is essential not only in elite sports, but also for the general population. By empha...

Background Improvements in movement quality (ie, how well an individual moves) facilitate increases in movement quantity, subsequently improving general health and quality of life. Wearable technology offers a convenient, affordable means of measuring and assessing movement quality for the general population, while technology more broadly can provi...

Inconsistency in the calculation of time spent in moderate to vigorous physical activity (MVPA) limits interstudy comparability and interpretation of surveillance data. This study assesses whether combining multiple individual methods results in a more accurate estimate of MVPA, while considering the influence of device brand and wear location. Par...

A cornerstone of asthma management is maintaining physical activity (PA), but this may lead to increased exposure to, and deeper inhalation of, pollutants. Furthermore, children and adolescents may be more susceptible to the deleterious impacts of such exposures. Despite the recent air quality campaigns and media coverage surrounding the dangers of...

Background Motor competence has important developmental associations with aspects of physical health, but there has been no synthesis of longitudinal associations with cognitive and social-emotional health. Objectives The first aim was to present a conceptual model that positions motor competence as a mediator between physical activity and cogniti...

Purpose: The development of sprint running during youth has received renewed interest, but questions remain regarding the development of speed in youth, especially the influences of sex, training, and maturity status. Methods: One hundred and forty-seven team sport trained (69 girls; 14.3 [2.1] y) and 113 untrained (64 girls; 13.8 [2.7] y) youth...

Purpose: To assess the association between the amount of recess provision and children's accelerometer-measured physical activity (PA) levels. Methods: Parents/guardians of 6- to 11-year-olds (n = 451) in the 2012 National Youth Fitness Survey reported recess provision, categorized as low (10-15 min; 31.9%), medium (16-30 min; 48.0%), or high (>...

Background Movement quality is typically assessed by drawing comparisons against predetermined movement standards. Movements are often discretely scored or labelled against pre-set criteria, though movement quality can also be evaluated using motion-related measurements (e.g., spatio-temporal parameters and kinematic variables). Wearable technology...

Purpose Fundamental movement skills (FMS) provide a crucial foundation for the development of complex movement patterns involved in physical activity and sport. Further, FMS and skill acquisition are proposed to have a moderating influence on the association between physical activity and cognitive stimulation. Despite this, there remains scant lite...

Peak oxygen uptake (V˙O2peak) is the ‘gold standard’ measure of youth aerobic fitness. There is no corresponding measure of anaerobic fitness and current understanding of the development of anaerobic fitness is principally founded on peak power output (PP) and mean power output (MP) during the Wingate anaerobic test. Multiplicative allometric model...

Recent decades have seen a dramatic increase in research focused on the influence of training on the aerobic and anaerobic fitness of youth. This has led to a growing body of evidence that suggests that children and adolescents are able to respond to training, irrespective of their maturity level. Specifically, peak oxygen uptake (V˙O2peak) and pul...

This book presents an integrated, research-driven, collection of 54 evidence-based chapters. Chapters are founded on the research and practical experience of 104 internationally renowned scientists and clinicians, from 25 countries. Each extensively referenced chapter concludes with a bulleted summary and where appropriate is cross-referenced to co...

Objective Identify prevalence of self-reported swallow, communication, voice and cognitive compromise following hospitalisation for COVID-19. Design Multicentre prospective observational cohort study using questionnaire data at visit 1 (2–7 months post discharge) and visit 2 (10–14 months post discharge) from hospitalised patients in the UK. Lasso...

Purpose: The potential impact of hormonal contraceptives (HCs) on player health and performance in women's rugby union (rugby) is not well understood, despite rugby's growing popularity worldwide. This study investigated the prevalence of HC use and reported associations with training and performance in a global sample of women rugby players. Met...

Regular exercise testing is recommended for all people with cystic fibrosis (PwCF). A range of validated tests, which integrate both strength and aerobic function, are available and increasingly being used. Together, these tests offer the ability for comprehensive exercise evaluation. Extensive research and expert consensus over recent years has en...

Repeated sprint ability (RSA) is more closely related to match performance outcomes than single-sprint performance, but the kinetic determinants in youth athletes remain poorly understood. Therefore, the aim of the study was to explore the kinetic determinants of RSA in youth athletes. Twenty trained adolescents (15 girls; 14.4 ± 1.0 years) complet...

Purpose: To investigate whether heterogeneous treatment effects occur for changes in inspiratory muscle strength, perceived dyspnoea, and health-related quality of life (QoL), following eight-weeks unsupervised home-based inspiratory muscle training (IMT) in adults with post-acute COVID-19 syndrome. Methods: In total, 147 adults with self-report...

Understanding the day-to-day lived experiences of individuals who have had or are still recovering from Coronavirus Disease-19 (COVID-19), whilst a complex challenge, presents the opportunity to listen and learn. Composite vignettes provide a novel approach to explore and present descriptive portrayals of the most commonly derived experiences and r...

Rugby Union (rugby) is a full-contact team sport characterised by frequent collision events. Over one third (2.7 million) of global rugby participants are women and girls. Yet, most rugby research, laws, and regulations are derived from the men’s game with limited transferability to the women’s game. This includes research focused on injury and con...

Background: Sleep disturbance is common following hospital admission both for COVID-19 and other causes. The clinical associations of this for recovery after hospital admission are poorly understood despite sleep disturbance contributing to morbidity in other scenarios. We aimed to investigate the prevalence and nature of sleep disturbance after d...

Long COVID, die lang anhaltende Krankheit und Erschöpfung, die bei einem kleinen Teil der SARS-CoV-2-Infizierten auftritt, stellt eine zunehmende Belastung für die Betroffenen und die Gesellschaft dar. Eine virtuelle Tagung der Physiological Society im Februar 2022 brachte Kliniker und Forscher zusammen, um das aktuelle Verständnis der Mechanismen,...

The benefits of physical activity (PA) and the negative impacts of sedentary time (SED) on both short- and long-term health in youth are well established. However, uncertainty remains about how PA and SED jointly influence maximal oxygen uptake (V˙O2max). Therefore, the aim of this study was to determine the joint influence of PA and SED on V˙O2max...

As individuals age, they encounter a series of transitions that shape their physical health, sense of purpose, identity, and perceptions of the world around them . These transitions, which include retirement, bereavement, relocation, and declining physical health, are pivotal moments in the lives of older adults . This article explores these potent...

The conceptualisation and visualisation of physical activity through 3D-printed objects offers a unique means by which to elicit positive behaviour change. This study aimed to explore whether 3D-printed models of physical activity obtain autotopographical meaning in youths and the influence of such models on their sense of personal and social ident...

Identifying the best analytical approach for capturing moderate-to-vigorous physical activity (MVPA) using accelerometry is complex but inconsistent approaches employed in research and surveillance limits comparability. We illustrate the use of a consensus method that pools estimates from multiple approaches for characterising MVPA using accelerome...

Background Sleep disturbance is common following hospitalisation both for COVID-19 and other causes. The clinical associations are poorly understood, despite it altering pathophysiology in other scenarios. We, therefore, investigated whether sleep disturbance is associated with dyspnoea along with relevant mediation pathways. Methods Sleep paramete...

The interrelationship between air pollution and childhood asthma is debated. Specifically, the management of asthma is partially dependent on maintaining physical activity (PA), but this may lead to increased exposure to, and deeper inhalation of, pollutants. Despite the recent air quality campaigns and media coverage surrounding the dangers of air...

Objective Inter-day reliability of sweat measurements, including the absorbent patch and modified iodine-paper techniques, at rest and exercise were evaluated. We further evaluated the effect of iodine paper size and the method of establishing sweat gland activation (sweat gland counting or surface area covered) on reliability. Furthermore, the rel...

Long COVID, the prolonged illness and fatigue suffered by a small proportion of those infected with SARS‐CoV‐2, is placing an increasing burden on individuals and society. A Physiological Society virtual meeting in February 2022 brought clinicians and researchers together to discuss the current understanding of long COVID mechanisms, risk factors a...

Background: Low physical activity levels in young children is a major concern. For children aged 0–5 years, engagement with opportunities to be physically active are often driven by the adults responsible for the child’s care. This systematic review explores the barriers and facilitators to parents/caregivers engaging pre-school children in communi...

Post COVID-19 condition can occur following infection with SARS-CoV-2 and is characterised by persistent symptoms, including fatigue, breathlessness and cognitive dysfunction, impacting everyday functioning. This study explored how people living with post COVID-19 experienced an eight-week inspiratory muscle training (IMT) rehabilitation programme....

Purpose: To identify associations between amount of school recess provision and children's physical activity (PA), weight status, adiposity, cardiorespiratory endurance, muscular strength, and muscular endurance. Method: Data from 6- to 11-year-old participants (n = 499) in the 2012 National Youth Fitness Survey were analyzed. Parents/guardians...

ActiGraph sampling frequencies of more than 30 Hz may result in overestimation of activity counts in both children and adults, but research on free-living individuals has not included the range of sampling frequencies used by researchers. Objective: We compared count- and raw-acceleration-based metrics from free-living children and adolescents ac...

The benefits of physical activity (PA) and the negative impacts of sedentary time (SED) on both short- and long-term health in youth are well established. However, uncertainty remains about how PA and SED jointly influence maximal oxygen uptake (V˙O 2max ). Therefore, the aim of this study was to determine the joint influence of PA and SED on peak...

Background: Although kidney transplantation is the best treatment for kidney failure, scarce research has examined its effects on physical activity, physical function and quality of life. Objectives: To investigate the experiences of a group of adults living with advanced kidney disease focusing on quality of life, physical activity and function...

Background The roles of physical activity (PA) and exercise within the management of cystic fibrosis (CF) are recognised by their inclusion in numerous standards of care and treatment guidelines. However, information is brief, and both PA and exercise as multi-faceted behaviours require extensive stakeholder input when developing and promoting such...

Issue Population level changes in physical activity (PA) may benefit from policy intervention. In response to the UN Sustainable Development Goals, Wales introduced legislation (the Well-being of Future Generations (Wales) Act 2015) to holistically improve health and well-being, including the translation of national policy into practice. This audit...

Background Youth have experienced unprecedented restrictions during the COVID-19 pandemic. It is important to ascertain youth's perceptions of how the lockdown restrictions have impacted their well-being. Given the varying restrictions imposed in different countries, exploring the impact relative to the specific restrictions is imperative. This stu...

Aims/hypothesis Lifestyle interventions are the first-line treatment option for body weight and cardiometabolic health management. However, whether age groups or women and men respond differently to lifestyle interventions is under debate. We aimed to examine age- and sex-specific effects of a low-energy diet (LED) followed by a long-term lifestyle...

Whilst participation in regular exercise and sport has generally increased over recent decades globally, fundamental questions remain regarding the influence of growth, maturation, and sex on the magnitude of training response throughout adolescence. Trained (108 participants, 43 girls; age: 14.3 ± 1.8 years) and untrained (108 participants, 43 gir...

The aim of this study was to compare the use of generic and cystic fibrosis (CF)-specific cut-points to assess movement behaviours in children and adolescents with CF. Physical activity (PA) was assessed for seven consecutive days using a non-dominant wrist-worn ActiGraph GT9X in 71 children and adolescents (36 girls; 13.5 ± 2.9 years) with mild CF...

ActiGraph counts are commonly used for characterizing physical activity intensity and energy expenditure and are among the most well-studied accelerometer metrics. Researchers have recently replicated the counts processing method using a mechanical setup, now allowing users to generate counts from raw acceleration data. Purpose : The purpose of thi...

Background: Modulator therapy represents a significant step forward in CF care and is expected to have a significant impact on the health and mortality of many individuals with CF. Studies have predominantly explored the physiological effects of modulator therapy on clinical outcomes, with little consideration of the individual lived experience of...

Background Exercise can be beneficial to cardiovascular system function, but its influence during pregnancy is less well understood. Heterogeneity in research studies has led to a lack of consensus on whether physical exercise during pregnancy can elicit cardiovascular adaptations during a period in which the cardiovascular system is already being...

Commonly used cut-points may misclassify physical activity (PA) in people with cystic fibrosis (CF). The aim of this study was to develop and cross-validate condition-specific cut-points in children and adolescents with CF. Thirty-five children and adolescents with CF (15 girls; 11.6 ± 2.8 years) and 28 controls (16 girls; 12.2 ± 2.7 years), had th...

Background: Population level changes in physical activity (PA) may benefit from policy intervention. In response to the United Nations Sustainable Development Goals, Wales introduced legislation to holistically improve health and well-being, including Public Service Boards, to improve the translation of national policy into practice. Method: An...

Background Treatment of end-stage renal disease (ESRD) is necessary to maintain life. However, it can cause physiological, psychosocial, and cognitive impairments, which may impact physical activity (PA) and sleep, although there is insufficient device-based data to elucidate such impacts. Methods PA, sedentary time (SED), and sleep were measured...

Background: Many people recovering from COVID-19 experience prolonged symptoms, particularly breathlessness. We urgently need to identify safe and effective COVID-19 rehabilitative strategies. The aim of the current study was to investigate the potential rehabilitative role of inspiratory muscle training (IMT). Methods: 281 adults (46.6±12.2 yea...

Physical activity is beneficial for arterial health in children but less is known about how all daily movement behaviours influence arterial stiffening. Compositional analysis can account for the co-dependent nature of these behaviours and therefore was employed to explore how the movement composition influences arterial health. Augmentation index...

Background: When people with chronic kidney disease reach kidney failure, renal replacement therapy is usually required to improve symptoms and maintain life. Although in-centre haemodialysis is most commonly used for this purpose, other forms of dialysis are available, including home haemodialysis and peritoneal dialysis. Objectives: We aimed t...

Physical activity (PA) participation was substantially reduced at the start of the COVID-19 pandemic. The purpose of this study was to assess the association between PA, mental health, and wellbeing during and following the easing of COVID-19 restrictions in the United Kingdom (UK) and New Zealand (NZ). In this study, 3363 adults completed online s...

Objective: The coronavirus disease-2019 (COVID-19) pandemic and national lockdowns took away opportunities for children to be physically active. This study aimed to determine the effect of the COVID-19 lockdown on accelerometer-assessed physical activity (PA) in children in Wales. Methods: 800 participants (8-18 years old), stratified by sex, ag...

Cardiovascular and haematological adaptations to endurance training facilitate greater maximal oxygen consumption (V̇O2max${\dot{V}_{{{\rm{O}}_{\rm{2}}}{\rm{max}}}}$), and such adaptations may be augmented following puberty. Therefore, we compared left ventricular (LV) morphology (echocardiography), blood volume, haemoglobin (Hb) mass (CO rebreathi...

Novel coronavirus disease 2019 (COVID-19) pandemic restrictions have negatively impacted physical activity (PA) and sedentary time/behaviour. This integrative review systematically explored the socioecological factors that impacted and influenced these movement behaviours in children and adolescents during the pandemic. Five electronic databases we...

Background: ActiGraph is a commonly used, research-grade accelerometer brand, but there is little information regarding intermonitor comparability of newer models. In addition, while sampling rate has been shown to influence accelerometer metrics, its influence on measures of free-living physical activity has not been directly studied. Purpose: To...

Background & Aims The association of quantity and quality of carbohydrate sources with appetite during long-term weight-loss maintenance (WLM) after intentional weight loss (WL) is unclear. We aimed to investigate longitudinal associations of quantity and quality of carbohydrate sources with changes in subjective appetite sensations during WLM. Me...

Background: Individuals with pre-diabetes are commonly overweight and benefit from dietary and physical activity strategies aimed at decreasing body weight and hyperglycemia. Early insulin resistance can be estimated via the triglyceride glucose index {TyG = Ln [TG (mg/dl) × fasting plasma glucose (FPG) (mg/dl)/2]} and the hypertriglyceridemic-high...

The aim of this study was to use a compositional analysis approach to account for the inherent co-dependencies between behaviours and to explore how daily movement behaviours influence cardiovascular health in children with and without T1D. Augmentation index, pulse wave velocity (PWV) and heart rate variability were measured in 20 children with (1...

Understanding of strategies to support individuals recovering from coronavirus disease 2019 (COVID-19) is limited. ‘Long COVID’ is a multisystem disease characterised by a range of respiratory, gastrointestinal, cardiovascular, neurological, and musculoskeletal symptoms extending beyond 12 weeks. The aim of this study was to explore individuals’ ex...

The aim of this meta-analysis was to quantify the change in sedentary time during the COVID-19 pandemic and its effect on health outcomes in the general population. One thousand six hundred and one articles published after 2019 were retrieved from five databases, of which 64 and 40 were included in the systematic review and meta-analysis, respectiv...

Population-level physical activity (PA) and sedentary time/behaviour estimates represent a significant public health issue exacerbated by restrictions enforced to control COVID-19. This integrative review interrogated available literature to explore the pandemic’s impact on correlates of such behaviours in adults (≥18 years). Five electronic databa...

Bronchiectasis is typically associated with considerable morbidity, reduced exercise capacity, and may impact upon quality of life. Children with cystic fibrosis (CF), the most common cause of childhood bronchiectasis, are now living longer than ever before. Given the functional and prognostic importance of aerobic fitness as well as peripheral and...

The time that animals spend travelling at various speeds and the tortuosity of their movement paths are two of the many things that affect space‐use by animals. In this, high turn rates are predicted to be energetically costly, especially at high travel speeds, which implies that animals should modulate their speed according to path characteristics...

This feasibility study explored the contextual factors influencing office workers’ adherence to an e-health intervention targeting total and prolonged sedentary time over 12 weeks. A three-arm quasi-randomized intervention included prompts at 30 or 60 min intervals delivered via a smartphone application, and a no-prompt comparison arm. Fifty-six of...

Purpose Cardiometabolic risk, including arterial stiffness, is increasing in youth. Those with asthma are suggested to be particularly at risk of cardiovascular disease. Efficient and effective strategies are required to prevent the atherosclerotic process in youth. The purpose of this study was to investigate the effect of 6 months high-intensity...

Purpose - Developing interventions that target population-specific motivational barriers to promote health behaviours is crucial, especially for older adults who are confronted with negative age stereotypes. This systematic review evaluates randomised and non-randomised field studies that tested the effects of age stereotype-based interventions on...

Background The ergogenic effects of dietary supplements on endurance exercise performance are well-established; however, their efficacy in hot environmental conditions has not been systematically evaluated. Objectives (1) To meta-analyse studies investigating the effects of selected dietary supplements on endurance performance and core temperature...

Purpose: To examine (1) associations between body fat percent (BF) and lifestyle behaviors in children aged 9-11 years and (2) the consistency of these associations over a 10-year period. Methods: In this repeat, cross-sectional study, 15,977 children aged 9-11 years completed an anthropometric assessment and the SportsLinx Lifestyle survey betwe...

Bronchiectasis is characterised by airflow obstruction and hyperinflation resulting in respiratory muscle weakness, and decreased exercise capacity. Inspiratory muscle training (IMT) is potentially an alternative treatment strategy to enhance respiratory muscle strength and endurance. Therefore, the aim was to investigate the effects of IMT on thos...

Early in the coronavirus-2019 (COVID-19) containment strategy, people with end-stage renal disease (ESRD) were identified as extremely clinically vulnerable and subsequently asked to ‘shield’ at home where possible. The aim of this study was to investigate how these restrictions and the transition to an increased reliance on telemedicine within cli...