Simon Fryer

Simon Fryer
University of Gloucestershire · School of Sport & Exercise

PhD

About

143
Publications
65,802
Reads
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1,668
Citations
Additional affiliations
January 2013 - present
University of Gloucestershire
Position
  • Professor (Associate)
January 2011 - December 2012
University of Canterbury

Publications

Publications (143)
Article
Full-text available
Background Previous reviews have shown that exposure to acute prolonged sitting can have detrimental effects on several cardiovascular and cardiometabolic health markers. However, to date, there has been no synthesis of peripheral blood pressure data (including systolic blood pressure, diastolic blood pressure and mean arterial pressure), an import...
Article
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Low intensity active recovery such as walking appears to be optimal for the clearance of blood lactate (BLa) concentration following high intensity exercise. However, within a sporting context, competition rules or procedural impracticalities often mean walking is not possible. Leg fidgeting during sitting has been shown to increase leg blood flow,...
Article
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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...
Article
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Prolonged uninterrupted sitting and a typical Western meal, high in fat and refined sugar, can additively impair cognitive and cerebrovascular functions. However, it is unknown whether interrupting these behaviours, with a simple desk-based activity, can attenuate the impairment. The aim of this study was to determine whether regular leg fidgeting...
Article
Full-text available
Purpose: Sport climbing is a technical, self-paced sport, and the workload is highly variable and mainly localized to the forearm flexors. It has not proved effective to control intensity using measures typical of other sports, such as gas exchange thresholds, heart rate, or blood lactate. Therefore, the purposes of the study were to (1) determine...
Article
Background & aims Atherosclerosis and arteriosclerosis contribute to vascular aging and cardiovascular disease (CVD) risk. Both processes can be assessed simply in the lower-limbs and reflect systemic pathology. However, only atherosclerosis is routinely assessed, typically via ankle-brachial index (ABI). Arteriosclerosis can be assessed using femo...
Article
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The aortic-femoral arterial stiffness gradient, defined as the ratio of femoral-ankle pulse wave velocity to carotid-femoral pulse-wave velocity, demonstrates good between-day reliability in young healthy adults.
Article
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Sedentary behavior, particularly sitting, is ubiquitous in many contemporary societies. This is a major societal concern considering the evidence for a strong association between sitting behavior and cardiovascular disease morbidity and mortality. Unsurprisingly, leading public health agencies have begun to advocate “reduction” in sitting behavior....
Article
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Independently, prolonged uninterrupted sitting and the consumption of a meal high in saturated fats acutely disrupt normal cardiovascular function. Currently, the acute effects of these behaviors performed in combination on arterial stiffness, a marker of cardiovascular health, are unknown. This study sought to determine the effect of consuming a h...
Article
Background: Aortic arterial stiffness is a strong independent predictor of cardiovascular disease (CVD); however, its dependence on mean arterial pressure (MAP) limits its clinical utility. The aortic-femoral arterial stiffness gradient (af-SG), a novel marker of CVD risk, may be a promising alternative, but its dependence on MAP is not known. The...
Article
Regular exposure to uninterrupted prolonged sitting and the consumption of high glycemic meals (HGI) is independently associated with increased cardiovascular disease risk. Sitting for as little as 1-hour can impair the health of both peripheral and central arteries. However, it is currently unknown whether combined acute exposure to uninterrupted...
Article
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Purpose: Sport climbing requires high-intensity finger flexor contractions, along with a substantial whole-body systemic oxygen uptake ([Formula: see text]O2) contribution. Although fatigue is often localised to the finger flexors, the role of systemic ̇[Formula: see text]O2 and local aerobic mechanisms in climbing performance remains unclear. As...
Article
Acute prolonged sitting leads to cerebrovascular disruptions. However, it is unclear how prolonged sitting interacts with other common behaviors, including high‐ (HGI) and low‐glycemic index (LGI) meals. Using a double‐blind randomized cross‐over design, this study evaluated the effects of prolonged (3 hr) sitting, with a high‐ (HGI; GI: 100) or lo...
Article
Background: The aortic to femoral arterial stiffness gradient (af-SG) may be a novel measure of arterial health and cardiovascular disease (CVD) risk, but its association with CVD risk factors and CVD status, and whether or not they differ from the referent measure, carotid-femoral pulse-wave velocity (cfPWV), is not known. Method: Accordingly,...
Article
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Background: Carotid-femoral pulse-wave velocity (cfPWV) is the reference standard measure of central arterial stiffness. However, it requires assessment of the carotid artery, which is technically challenging, and subject-level factors, including carotid artery plaque, may confound measurements. A promising alternative that overcomes these limitati...
Article
Full-text available
Objectives To assess the effect of a home-based over-ground robotic-assisted gait training program using the AlterG Bionic Leg orthosis on clinical functional outcomes in people with chronic stroke. Design Randomized controlled trial. Setting Home. Participants Thirty-four ambulatory chronic stroke patients who recieve usual physiotherapy. Inte...
Article
Objectives: To assess physical activity (PA), mental health and well-being of adults in the UK, Ireland, New Zealand and Australia during the initial stages of National governments’ Coronavirus disease (COVID-19) containment responses. Design: Observational, cross-sectional Methods: An online survey was disseminated to adults (n = 8,425; 44.5 ± 1...
Article
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It has been well established that challenge and threat evaluations affect the performance of potentially stressful tasks. However, the factors that influence these evaluations have rarely been examined. Objective : This study examined the effects of ego depletion on challenge and threat evaluations during a public speaking task. Method : 262 part...
Article
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Background Exposure to acute prolonged sitting can result in vascular dysfunction, particularly within the legs. This vascular dysfunction, assessed using flow-mediated dilation (FMD), is likely the consequence of decreased blood flow-induced shear stress. With mixed success, several sitting interruption strategies have been trialled to preserve va...
Article
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The aims of the present study were to analyze the effects of 16 weeks of different aerobic exercise training (ExT) programs with diet on cardiac autonomic modulation and hemodynamics in nonphysically active and overweight/obese adults (n = 249, 53.7 ± 8.0 years) with primary hypertension, and the possible differences among ExT programs and their ef...
Article
Anthocyanin-rich New Zealand blackcurrant (NZBC) may improve forearm muscle oxygenation and enhance performance in high-level rock climbers. As such, using a double-blind, randomised, cross-over design study, twelve participants performed an oxidative capacity assessment, and two successive exhaustive exercise trials (submaximal forearm muscle cont...
Article
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Purpose: The fatigue resistance of the finger flexors is known to be a key determinant of climbing performance. This study set out to establish the association between the single all-out assessment of finger flexor critical force (ff-CF) and the impulse above CF (W') on climbing performance (self-reported sport and boulder climbing ability). Meth...
Article
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The purpose of this study was to investigate the relationship between attention (using two different attention tasks) and self-reported climbing ability while considering potential confounding factors (sex, age, climbing experience, and cardiorespiratory fitness) in a group of experienced climbers. Accuracy of response (AC) and reaction time (RT) f...
Preprint
Full-text available
Objectives: To assess how the early stages of National governments Coronavirus disease (COVID-19) containment strategies impacted upon the physical activity, mental health and well-being of adults in the UK, Ireland, New Zealand and Australia Design: Observational, cross-sectional Setting: Online survey disseminated in the UK, Ireland, New Zealand...
Article
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Flow-mediated slowing (FMS), defined as the minimum pulse wave velocity (PWV min ) during reactive hyperemia, is potentially a simple, user-objective test for examining endothelial function. The purpose of the current study was to determine the effects of a known endothelial dysfunction protocol on arm PWV and PWV min . Complete data were successfu...
Article
The delivery to and utilization of oxygenated hemoglobin to the forearm muscles are key determinants of rock-climbing performance. Anthocyanin-rich New Zealand blackcurrant (NZBC) has been suggested to improve blood flow and may enhance forearm endurance performance. As such, a double-blind, randomized crossover design study with 12 participants pe...
Article
Background: Carotid-femoral pulse wave velocity (cfPWV) is widely used in epidemiological studies to assess central arterial stiffness. However, despite being superior to traditional risk factors in predicting cardiovascular outcomes, cfPWV is not routinely used in clinical practice. cfPWV assessments require applanation of the carotid artery, whi...
Article
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Metabolically unhealthy obesity (MUO) is a regular state in people with primary hypertension (HTN), obesity, and who are physically inactive. To achieve and maintain a metabolically healthy overweight/obese (MHO) state should be a main treatment goal. The aims of the study were (1) to determine differences in metabolic profiles of overweight/obese,...
Article
Introduction: Carotid-femoral pulse wave velocity (cfPWV) is widely used in clinical and epidemiological studies to assess central arterial stiffness and predict cardiovascular outcomes. However, cfPWV assessments require applanation of the carotid artery, which may be challenging in some patients, and assessments may be confounded in the presence...
Article
Full-text available
This study examined the effects of ego depletion on challenge and threat states and cerebral hemodynamic responses to a pressurized muscular endurance task requiring self-control. Following the ethical approval, 58 participants (39 male, 19 female; Mage = 28 years, SD = 12) were randomly assigned to either an experimental or a control group. Partic...
Article
There has been a great deal of interest into the effects of prolonged sitting on lower limb vascular function. However, most studies use flow mediated dilation which is technically challenging. A simpler technique is pulse wave velocity (PWV) which can be estimated at any single arterial site of interest using a number of different calculations [Br...
Article
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Purpose: To determine whether improvements in cardiorespiratory fitness (CRF), blood pressure (BP) and body composition previously seen after a 16-week exercise intervention (POST) with hypocaloric diet are maintained following six months (6M) of unsupervised exercise time. Methods: Overweight/obese, physically inactive participants with primary hy...
Article
Exposure to acute prolonged sitting reportedly leads to decreased cerebral blood flow. However, it is unclear whether this exposure translates to decreased cerebral perfusion and executive function or whether simple strategies to break up sitting can maintain cerebral perfusion and executive function. This study sought to answer two questions: in y...
Article
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Pulse wave analysis (PWA) utilizes arm blood pressure (BP) waveforms to estimate aortic waveforms. The accuracy of central BP waveform estimation may be influenced by assessment site local haemodynamics. This study investigated whether local haemodynamic changes, induced via arm tilting ±30° relative to heart level, affect estimated central systoli...
Article
New findings: What is the central question of this study? There is growing interest on the effects of sedentarism on central and peripheral cardiovascular health. To permit further investigation, including in larger epidemiological studies, there is a need to identify arterial health assessment tools that are valid (accurate) and reliable (precise...
Poster
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Assessment of the SphygmoCor XCEL device's between-day reliability for measures of pulse wave velocity (PWV).
Article
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Purpose: To determine if the mathematical model used for the estimation of critical force (CF) and the energy store component W' is applicable to intermittent isometric muscle actions of the finger flexors of rock climbers, using a multi-session test. As a secondary aim, the agreement of estimates of CF and W' from a single-session test were also d...
Article
Intermittent exposure to hypoxia can lead to improved endurance performance. Currently, it is unclear whether peripheral adaptions play a role in improving oxygen delivery and utilization following both training and detraining. This study aimed to characterize skeletal muscle blood flow (mBF), oxygen consumption (mV̇O2), and perfusion adaptations t...
Article
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Cardiorespiratory fitness (CRF) is positively associated with enhanced cardiovascular health. This cross-sectional study aimed to determine associations between CRF and the biochemical profile of overweight/obese adults diagnosed with primary hypertension (HTN). Does cardiorespiratory fitness (exposure) positively affect the biochemical profile (ou...
Article
Objective: To determine which ultrasound-based, single-point arterial stiffness estimate is least dependent on blood pressure (BP) to improve assessment of local vascular function. Methods: Ultrasound was used to assess blood flow and diameters at the left brachial artery of 20 healthy adults [55% female, 27.9 years (5.2), 24.2 (2.8) kg/m]. BP o...
Article
Prolonged, uninterrupted sitting negatively impacts markers of peripheral vascular health, particularly, vasodilatory function of leg arteries. Whether sitting can similarly impact measures of central vascular health, as well as overall leg vasoreactivity (i.e., vasodilatory and vasoconstrictor function) remains unknown. To address this, measuremen...
Poster
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METHODS Onsight climbing ability and BMD using dual energy X-ray absorptiometry (DXA) (Figure 1 and 2) were assessed in five rock climbers (4 females). PURPOSE To analyze the changes in BMD following 10-years of rock climbing. RESULTS After 10-years, mean climbing ability was significantly higher in 2015 vs 2005 for all climbers (7b vs 7a, p=0.025)...
Poster
Central hemodynamic parameters, such as aortic systolic pressure (cSBP), augmentation index (AIx), and pressure wave forms (Pb) may offer clinicians superior prognostic information to peripheral systolic pressure (SBP). It is unknown whether changes in peripheral hemodynamics affect central hemodynamic measurements. The purpose of this study was to...
Article
Full-text available
Stroke is a major global health problem whereby many survivors have unmet needs concerning mobility during recovery. As such, the use of robotic assisted devices (i.e., a bionic leg) within a community-setting may be an important adjunct to normal physiotherapy in chronic stroke survivors. This study will be a dual-centre, randomized, parallel grou...
Article
Cardiovascular autonomic nervous system function can be assessed using an orthostatic challenge to induce arterial wave reflection. While arterial reflection is typically estimated using a central augmentation index, a superior estimation can be obtained using pulse wave separation analysis to estimate the aortic backward pressure wave (Pb). Howeve...
Article
Full-text available
Background Both exercise training and diet are recommended to prevent and control hypertension and overweight/obesity. Purpose The purpose of this study was to determine the effectiveness of different 16-week aerobic exercise programmes with hypocaloric diet on blood pressure, body composition, cardiorespiratory fitness and pharmacological treatme...
Article
Background and aims: Although it is well known that resistance training (RT) is beneficial for patients suffering from a variety of cardiovascular diseases, it remains underutilized as a rehabilitation tool as there is no reliable way to monitor the additional stress placed on the central organs. The current study aimed to determine between-day re...
Article
Objective: to examine the current level of understanding held by midwives regarding the NICE physical activity guidelines in the UK, and to investigate the physical activity guidance given to women during pregnancy. Design: an 11 question online survey comprising of a mixture of closed and open ended questions. Setting: data reflects participa...
Article
Baláš, J, Kodejška, J, Krupková, D, Hannsmann, J, and Fryer, S. Reliability of near-infrared spectroscopy for measuring intermittent handgrip contractions in sport climbers. J Strength Cond Res 32(2): 494-501, 2018-The use of near-infrared spectroscopy (NIRS) to investigate muscle oxygenation changes during physical tasks such as rock climbing has...
Article
This study examined differences in the oxygenation kinetics and strength and endurance characteristics of boulderers and lead sport climbers. Using near infrared spectroscopy, 13-boulderers, 10-lead climbers, and 10-controls completed assessments of oxidative capacity index and muscle oxygen consumption (mV˙O2) in the flexor digitorum profundus (FD...
Conference Paper
Full-text available
Following institutional ethical approval, 9 healthy males who were not forearm trained (mean age: 20.7 ± 1.1 years; stature: 1.77 ± 0.08 m; body mass: 84.0 ± 14.2 kg) volunteered to take part in the study. In a randomized, crossover design participants completed four weeks of progressive HGD endurance training (0.3Hz in week one increasing to 1.2Hz...