Ali McManus

University of British Columbia - Okanagan | UBC Okanagan · School of Health and Exercise Sciences

Chronic exercise training is associated with an 'athlete's artery' phenotype in young adults and an attenuated age-related decline in endothelium-dependent arterial function. Adolescence is associated with an influx of sex-specific hormones that may exert divergent effects on endothelial function, but whether training adaptations interact with biol...

Cerebral blood velocity (CBv) increases in response to moderate exercise in humans, but the magnitude of change is smaller in children compared to post-pubertal adolescents and adults. Whether sex differences exist in the anterior or posterior CBv response to exercise across pubertal development remains to be determined. We assessed middle cerebral...

Global cerebral blood flow (gCBF) and cerebrovascular reactivity to hypercapnia (CVRCO2${\mathrm{CV}}{{\mathrm{R}}_{{\mathrm{C}}{{\mathrm{O}}_{\mathrm{2}}}}}$) are modulated by gonadal hormone activity, while insulin‐like growth factor 1 facilitates exercise‐mediated cerebral angiogenesis in adults. Whether critical periods of heightened hormonal a...

The purpose of this study was to examine the effect of an acute bout of prolonged sitting with and without exercise breaks on cerebrovascular function in 7‐ to 13‐year‐old children. Forty‐two children and adolescents were recruited to a crossover trial, with 15 girls (mean age 10.1 ± 2.5 years) and 16 boys (mean age 10.5 ± 1.3 years) completing the...

During exercise, children and adolescents adopt a different breathing pattern and hyperventilate for a given metabolic demand compared to adults. The ventilatory threshold occurs at a higher percentage of peak oxygen uptake (V˙O2peak) and the phase I delay and phase II ventilation time constant at the onset of exercise increase with age. After a ra...

Various studies have linked exercise to brain structure and function, but the mechanistic pathways underlying exercise-induced benefits are poorly understood. Augmented brain function is related to cerebrovascular responses to exercise in adults; however, evidence in children is limited. This is an emerging area of integrative paediatric exercise p...

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...

Neurovascular coupling (NVC) is mediated via nitric oxide signalling, which is independently influenced by sex hormones and exercise training. Whether exercise training differentially modifies NVC pre- vs. post-puberty, where levels of circulating sex hormones will differ greatly within- and between-sexes, remains to be determined. Therefore, we in...

Maturational differences exist in cardiopulmonary and cerebrovascular function at sea‐level, but the impact of maturation on acclimatization responses to high altitude is unknown. Ten children (9.8 ± 2.5 years) and 10 adults (34.7 ± 7.1 years) were assessed at sea‐level (BL), 3000 m and twice over 4 days at 3800 m (B1, B4). Measurements included mi...

Intracranial blood velocity reactivity to a steady-state hypercapnic stimulus has been shown to be similar in children and adults, but the onset response to hypercapnia is slower in the child. Given the vasodilatory effect of hypercapnia on the cerebrovasculature, assessment of vessel diameter, and blood flow are vital to fully elucidate whether th...

The execution of clinical trials can be expensive and present logistical challenges regarding recruitment and retention of participants. Innovative research design fostering convenience by eliminating research facility visits may enhance recruitment and retention. We examined the feasibility of a remote clinical trial in people living with type 2 d...

Introduction Exercise and physical activity (PA) are fundamental to the treatment of type 2 diabetes. Current exercise and PA strategies for newly diagnosed individuals with type 2 diabetes are either clinically effective but unsuitable in routine practice (supervised exercise) or suitable in routine practice but clinically ineffective (PA advice)....

We explored the influence of sex and maturation on resting cervical artery hemodynamics (common carotid artery, CCA; internal carotid artery, ICA; and vertebral artery, VA) and free-living physical activity and sedentary behavior in children 6-17 years of age. Additionally, we investigated the relationship between physical activity and sedentary be...

Your heart works as a team with your body’s blood vessels. Your heart pumps the blood, while blood vessels help the blood travel all over your body, just as a garden hose helps move water all around your garden. Blood carries oxygen and other nutrients to your muscles and organs and removes carbon dioxide and other wastes. These are very important...

New findings: What is the central question of this study? This study investigated intracranial cerebrovascular and ventilatory reactivity to 6% CO2 in children and adults and explored dynamic ventilatory and cerebrovascular onset responses. What is the main finding and its importance? We show cerebrovascular reactivity is similar in children and a...

The purpose of the study was to examine whether a higher aerobic fitness in 9-10 year old children is related to superior macro and microvascular health and cardiovascular disease (CVD) risk. Ninety-six 9-10 year olds (53 boys) completed the study. Body composition was assessed from air displacement plethysmography and magnetic resonance imaging. P...

Purpose: The effect of exercise intensity on vasodilator function is poorly understood in children. The authors compared the acute effect of high-intensity interval exercise (HIIE) with moderate-intensity steady-state exercise (MISS) on postexercise vasodilation and shear patterns in 7- to 12- year-old children. Methods: Superficial femoral arte...

Objective To investigate scaling approaches for evaluating the development of peak VO2 and improving the identification of low cardiopulmonary fitness in Southern Chinese children and adolescents. Methods Nine hundred and twenty Chinese children and adolescents (8 to 16 years) underwent graded cardiopulmonary exercise test on a treadmill until vol...

Scatterplots relating VO2 to age for boys. (TIF)

Calculator for z score of peak VO2. (XLSX)

Scatterplots relating VO2 to age for girls. (TIF)

Purpose: To understand the extent different types of acute exercise influence cerebral blood flow during and following exercise in children. Methods: Eight children (7-11 y; 4 girls) completed 2 conditions: high-intensity interval exercise (HIIE; 6 × 1-min sprints at 90% watt maximum) and moderate-intensity steady-state exercise (MISS; 15 min at...

Understanding the process of successful adaptation to high altitude provides valuable insight into the pathogenesis of conditions associated with impaired oxygen uptake and utilization. Prepubertal children residing at low altitude show a reduced cerebrovascular response to exercise in comparison to adults, and a transient uncoupling of cerebral bl...

The University of British Columbia Nepal Expedition took place over several months in the fall of 2016 and was comprised of an international team of 37 researchers. This paper describes the objectives, study characteristics, organization and management of this expedition, and presents novel blood gas data during acclimatization in both lowlanders a...

Physiological responses to hypoxia in children are incompletely understood. We aimed to characterize cerebrovascular and ventilatory responses to normobaric hypoxia in girls and women. Ten healthy girls (9.9 ± 1.7 years; mean ± SD; Tanner stage 1 and 2) and their mothers (43.9 ± 3.5 years) participated. Internal carotid (ICA) and vertebral artery (...

Developmental cerebral hemodynamic adaptations to chronic high-altitude exposure, such as in the Sherpa population, are largely unknown. To examine hemodynamic adaptations in the developing human brain, we assessed common carotid (CCA), internal carotid (ICA), and vertebral artery (VA) flow and middle cerebral artery (MCA) velocity in 25 (9.6 ± 1.0...

Comprehensive and up to date, this textbook on children’s sport and exercise medicine features research and practical experience of internationally recognized scientists and clinicians that informs and challenges readers. Four sections—Exercise Science, Exercise Medicine, Sport Science, and Sport Medicine—provide a critical, balanced, and thorough...

Comprehensive and up to date, this textbook on children’s sport and exercise medicine features research and practical experience of internationally recognized scientists and clinicians that informs and challenges readers. Four sections—Exercise Science, Exercise Medicine, Sport Science, and Sport Medicine—provide a critical, balanced, and thorough...

Comprehensive and up to date, this textbook on children’s sport and exercise medicine features research and practical experience of internationally recognized scientists and clinicians that informs and challenges readers. Four sections—Exercise Science, Exercise Medicine, Sport Science, and Sport Medicine—provide a critical, balanced, and thorough...

Comprehensive and up to date, this textbook on children’s sport and exercise medicine features research and practical experience of internationally recognized scientists and clinicians that informs and challenges readers. Four sections—Exercise Science, Exercise Medicine, Sport Science, and Sport Medicine—provide a critical, balanced, and thorough...

Little is known about the response of the cerebrovasculature to acute exercise in children and how these responses might differ with adults. Therefore, we compared changes in middle cerebral artery blood velocity (MCAVmean), partial pressure of end-tidal carbon dioxide (PETCO2), blood pressure and ventilation (VE) in response to incremental exercis...

New Findings What is the central question of this study? Children are spending more than 60% of their waking day sedentary. The consequences of excessive sedentary behaviour are not well understood in the child, but there is growing evidence that with increasing sedentary time, cardiovascular risk in childhood also increases. What is the main findi...

Aim To provide an evidence-based review of muscle metabolism changes with sex-, age- and maturation with reference to the development of youth sport performance. Methods A narrative review of data from both invasive and non-invasive studies, from 1970 to 2015, founded on personal databases supported with computer searches of PubMed and Google Scho...