Perceived Exertion Relationships in Adults and Children

The ratings of perceived exertion are commonly employed within both a clinical and exercise setting to quantify, monitor and evaluate an individual’s exercise tolerance and level of exertion. Recent advances in the area of perceived exertion have led to novel applications in the use of the ratings of perceived exertion scale as a means of predicting an individual’s maximal functional capacity (VO2max) for exercise (Eston, Lamb, Parfitt, & King, 2005; Eston, Faulkner, Mason, & Parfitt, 2006; Eston, Lambrick, Sheppard, & Parfitt, 2008; Faulkner, Parfitt, & Eston, 2007). Yet the utility of such procedures with low-fit individuals or children has received little or no research attention. As such, one aim of this thesis was to assess the efficacy of the ratings of perceived exertion in predicting the VO2max of low-fit men and women, and healthy children. It is often presumed that like adults, a child’s perception of exertion rises linearly with increases in exercise intensity, despite a limited amount research suggesting otherwise. Moreover, there is a lack of empirical evidence to suggest that children regulate their power output during a closed-loop exercise task in order to complete a given distance in the fastest time possible. Therefore, a further aim of this thesis was to explore the nature of the perceptual responses of young children across differing modes of exercise, and to examine whether children employ pacing strategies during running. In relation to this latter aim, it was of particular interest to explore pacing in relation to the ratings of perceived exertion during running, as the ratings of perceived exertion have been proposed as a key component of such a regulatory system during exercise (Tucker, 2009). This thesis comprises a qualitative review of relevant literature, and six study chapters which were borne out of five empirical studies. The findings of studies 1 and 2 (chapters 3 & 4, respectively) support the utility of the ratings of perceived exertion to estimate VO2max in low-fit men and women, during cycle ergometry exercise. Importantly, this has been shown from a single exercise test at a low-moderate exercise intensity, during either a step-incremental (study 1) or ramp-incremental (study 2) protocol. Studies 3 and 4 (chapters 5 & 6, respectively) provide evidence to suggest that a child’s perception of exertion may rise linearly or curvilinearly in relation to increasing work, during either cycle ergometry or treadmill exercise. These studies support the utility of a unique, curvilinear, paediatric ratings of perceived exertion scale in obtaining accurate exertional responses from young children, across differing modes of exercise. In contrast to studies 1 and 2, study 5 (chapter 7) suggests that the novel means of predicting maximal functional capacity from submaximal ratings of perceived exertion in adults is inaccurate with young children. This was particularly evident in the low intraclass correlation coefficients and wide limits of agreement obtained between measured- and predicted VO2max, for both cycle ergometry and treadmill exercise. Study 6 (chapter 8) demonstrated that young children employ pacing strategies during an 800 m run, similar to adults, and that this improves with trial familiarisation. Moreover, the presence of other competitors has a detrimental effect on performance, particularly for girls

The influence of a six-week, high-intensity games intervention on the pulmonary oxygen uptake kinetics in prepubertal obese and normal-weight children

Background: The pulmonary oxygen uptake ( O2) response is deleteriously influenced by obesity in pre-pubertal children, as evidenced by a slower phase II response. To date, no studies have investigated the ability of an exercise intervention to ameliorate this. Objectives: To investigate the influence of a six week, high-intensity games orientated intervention on the O2 kinetic response of pre-pubertal obese (OB) and normal-weight (NW) children during heavy intensity exercise. Methods: Thirteen NW and fifteen OB children participated in a twice-weekly exercise intervention involving repeated bouts of 6-minutes of high-intensity, games-orientated exercises followed by 2 minutes of recovery. Sixteen NW and 11 OB children served as a control group. At baseline and post-intervention, each participant completed a graded-exercise test to volitional exhaustion and constant work rate heavy intensity exercise.Results: Post intervention, OB children demonstrated a reduced phase II τ (Pre: 30±8 cf. Post: 24±7 s), MRT (Pre: 50±10 cf. Post: 38±9 s) and phase II amplitude (Pre: 1.51±0.30 cf. Post: 1.34±0.27 l∙min-1). No changes were evident in the NW children. Conclusions: The present findings demonstrate that a six-week, high-intensity intervention can have a significant positive impact on the dynamic O2 response of obese pre-pubertal children

Correction:Physical activity and mental health experiences of people living with long term conditions during COVID-19 pandemic: A qualitative study

Notice of republication This article was republished on March 14 th, 2024, to correct the author list and add Danielle Lambrick and James Faulkner as the third and fourth authors respectively. Please download this article again to view the correct version. The originally published, uncorrected article and the republished, corrected articles are provided here for reference. (PLoS ONE (2023) 18: 7 (e0285785) DOI: 10.1371/journal.pone.0285785)</p

Effects of Upright and Recumbent Cycling on Executive Function and Prefrontal Cortex Oxygenation in Young Healthy Men

Background: The purpose of this study was to assess the acute effects of posture (upright vs. recumbent) during moderate-intensity cycle exercise on executive function and prefrontal cortex oxygenation, in young healthy adults. Methods: Seventeen physically active men (24.6 ± 4.3y) completed two 30-minute submaximal, exercise tests (Conditions: upright and recumbent cycle ergometry). Executive function was assessed using the ‘colour’ and ‘word’ Stroop task, pre- (resting) and post-exercise. Regional oxygen saturation (rSO2) to the prefrontal cortex was continuously monitored using near-infrared spectroscopy. Results: Significant improvements in executive function (Stroop colour and word tasks) were observed following 30 minutes of exercise, for both upright and recumbent cycling (P &lt; .05). However, there were no differences in executive function between cycling Conditions (P &gt; .05). A significant increase in rSO2 was recorded immediately post-exercise compared to pre-exercise for both Conditions (P &lt; .05), with a trend (P = .06) for higher peak rSO2 following recumbent cycling compared to upright cycling (81.9 ± 6.5 cf. 79.7 ± 9.3%, respectively). Conclusions: Although submaximal cycling exercise acutely improves cognitive performance and prefrontal oxygenation, changes in cognition are not perceived to be dependent on body posture in young, healthy men

Physical Activity, Mental Health and Wellbeing During the First COVID-19 Containment in New Zealand: A Cross-Sectional Study.

Strategies implemented worldwide to contain COVID-19 outbreaks varied in severity across different countries, and established a new normal for work and school life (i.e., from home) for many people, reducing opportunities for physical activity. Positive relationships of physical activity with both mental and physical health are well recognised, and therefore the aim was to ascertain how New Zealand’s lockdown restrictions impacted physical activity, mental health and wellbeing. Participants (n = 4007; mean ± SD: age 46.5 ± 14.7 years, 72% female, 80.7% New Zealand European) completed (10–26 April 2020) an online amalgamated survey (Qualtrics): International Physical Activity Questionnaire: Short Form; Depression, Anxiety and Stress Scale-9; World Health Organisation-Five Well-Being Index; Stages of Change Scale. Positive dose–response relationships between physical activity levels and wellbeing scores were demonstrated for estimates that were unadjusted (moderate activity OR 3.79, CI 2.88–4.92; high activity OR 8.04, CI 6.07–10.7) and adjusted (confounding variables: age, gender, socioeconomic status, time sitting and co-morbidities) (moderate activity 1.57, CI 1.11–2.52; high activity 2.85, CI 1.97–4.14). The study results support previous research demonstrating beneficial effects of regular physical activity on mental health and wellbeing. Governments may use these results to promote meeting physical activity guidelines in order to protect mental health and wellbeing during the ongoing COVID-19 restrictions and future pandemics

Reliability of oscillometric central blood pressure and central systolic loading in individuals over 50 years:Effects of posture and fasting

Background and aims The between-day reliability of oscillometric pulse wave analysis has been demonstrated in a young, healthy population but not in an older sample. This study examined the between-day reliability of the SphygmoCor XCEL in individuals over 50 years. As blood pressure is measured in a range of postures and fasting states (supine/seated, fasted/non-fasted), this study also investigated the effect of these variables on central blood pressure and central systolic loading. Methods Fifty-one adults (m = 21; age 57 ± 6.4 y) were tested on three mornings in supine and seated conditions and in fasted and non-fasted states. Data was analysed as a whole and for normotensive (n = 25) and hypertensive participants (n = 26). Results SphygmoCor XCEL demonstrated strong reliability in the whole sample for central systolic and diastolic blood pressures, augmentation index (AIx) and AIx75 (ICC = 0.77–0.95). Significant interaction effects were observed in central diastolic blood pressure, central pulse pressure, augmentation index (AIx) and AIx75 (p &lt; 0.05; ηp 2 = 0.10–0.23). Fasting state had a greater influence on central pressures in a seated than supine posture, but a greater effect on central systolic loading measures in a supine posture. Conclusions The SphygmoCor XCEL is a reliable tool to assess central haemodynamic variables in an older population. It would be pertinent for clinicians and researchers to record central measures in a supine posture to minimise the effects of food consumption. Conversely, the assessment of central systolic loading should occur in a seated condition to minimise the influence of varying fasting states.</p

The aortic-femoral arterial stiffness gradient demonstrates good between-day reliability

In a healthy cardiovascular system, arterial stiffness progressively increases from the elastic aorta to the muscular conduit arteries of the periphery. This stiffness gradient permits a gradual attenuation of the forward pressure wave into a smooth consistent blood flow and prevents the transmission of pulsatile forces to the microcirculation and endorgans [1]. However, aging and lifestyle factors may disrupt these beneficial phenomena [2]. In particular, the aorta tends to stiffen, whereas changes in lower-limb arterial stiffness, for example, are less marked [2]. These differential changes in stiffness lead to a reversal of the stiffness gradient, increasing forward pressure transmission, and contributing to end-organ damage [1, 3]. A recent study reported that the stiffness gradient between aortic and lower-limb arterial stiffness provided prognostic information beyond the carotid-femoral pulse-wave velocity (cfPWV), a criterion measure of arterial health [4]. This measure provides a promising opportunity to gain meaningful insight into the hemodynamic integration of the vascular system. However, a measurement must have acceptable precision (reliability) to be of value in clinical and research settings. Therefore, the objective of this study was to estimate the between-day reliability of the aortic-femoral arterial stiffness gradient (af-SG)

Effects of robotic-assisted gait training on the central vascular health of individuals with spinal cord injury: A pilot study.

Objective: To investigate the effect of a short-term, robotic-assisted (exoskeleton) gait training (RGT) program on central and peripheral hemodynamic measures in patients with spinal cord injury (SCI). Design: Parallel group, non-randomized trial with before (baseline) and after (follow-up) assessments. Setting: Single-center, community-based neuro-physiotherapy practice. Participants: Twelve individuals with SCI (ASI A to C). Interventions: Participants completed either a 5-day RGT program plus physiotherapy (n = 6), or a usual care physiotherapy only program (control group; n = 6). The RGT program consisted of daily 60-min physiotherapy and 90-min of RGT. Outcome measures were measured before and after the rehabilitation program. Main outcome measure(s): The primary outcome measure was arterial wave reflection (Augmentation index [AIx]), with central and peripheral blood pressures also reported. Data are presented as mean (SD) and effect sizes (partial eta squared; η2 p). Results: There was a significant reduction in AIx (30 ± 18–21 ± 15%; η2 p=0.75) and mean arterial pressure (89 ± 11–82 ± 10 mmHg; η2 p=0.47) following completion of the RGT program (both P &lt; 0.05). There were no changes in these measures for the control group. Although not significantly different, medium to large effects were observed in favor of RGT for all other central and peripheral measures (η2 p=0.06–0.21), except for heart rate and pulse pressure (η2 p&lt;0.04). Conclusions: RGT using an exoskeleton is a promising therapy for improving cardiovascular health in patients with SCI. Specifically, this study indicates decreased arterial wave reflection and supports the need for larger randomized controlled trials

Genotype vs. phenotype and the rise of non-communicable diseases: the importance of lifestyle behaviors during childhood

Despite continued research and growing public awareness, the incidence of non-communicable diseases (NCD) continues to accelerate. While a person may have a genetic predisposition to certain NCDs, the rapidly changing epidemiology of NCDs points to the importance of environmental, social, and behavioural determinants of health. Specifically, three lifestyle behaviours expose children to important environmental cues and stressors: physical activity, nutritional intake, and sleep behaviour. Failure to expose children to proper gene-environment interactions, through the aforementioned lifestyle behaviours, can and will predispose children to the development of NCDs. Reengineering the environments of children can induce a paradigm shift, from a predominantly biomedical health model of treating symptomology, to a more holistic model based on encouraging appropriate behavioral decisions and optimal health

Oscillometric central blood pressure and central systolic loading in stroke patients:Short-term reproducibility and effects of posture and fasting state

Background This study examined the short-Term reproducibility of non-invasive estimates of central and peripheral blood pressure and markers of central systolic loading (augmentation index [AIx; a measure of central systolic loading] and AIx75 [AIx standardised to 75 b ·min-1 heart rate]) and the effect of posture and fasting state on these variables in patients with acute stroke. Methods Twenty-Two acute stroke patients (72 ± 10y) had blood pressure measured using the SphygmoCor XCEL in supine and seated postures and whilst fasted and non-fasted. Results Acceptable short-Term reproducibility (ICC &gt;0.75) was reported for all peripheral and central variables in all conditions (ICC = 0.77-0.90) and for AIx and AIx75 in both fasted postures (ICC = 0.78-0.81). Food consumption significantly lowered all blood pressures (p &lt;0.05; η2; p = 0.20-0.55). The seated posture resulted in a significantly greater AIx than supine (p &lt;0.05; η2; p = 0.22). Fasting state had significant main effects on AIx and AIx75 (p &lt;0.05; η2; p = 0.14-0.22). Conslusions Oscillometric estimates of central blood pressure have high short-Term reproducibility in different postures and fasting states but markers of systolic load should be assessed whilst fasted. Fasting state has a large effect on central and peripheral blood pressures and on measures of systolic loading. It is important for clinicians to be aware of optimal assessment conditions without this impacting on patient wellbeing. Trial registration Clinical trial registry name: NCT02537652.</p