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Potentiating Response to Drop-Jump Protocols on Sprint Acceleration: Drop-Jump Volume and Intrarepetition Recovery Duration
Get PDFThe purpose of this study was to investigate the postactivation potentiation response first to bounce drop jump (BDJ) volume; second, BDJ intrarepetition recovery duration and recovery duration between BDJs and 20-meter (including 5- and 10-m split times) sprint performance. The study was undertaken in 2 parts, the first part compared different volumes of BDJs and the second part compared different BDJ intrarepetition recovery periods. The effect of recovery periods between the BDJs and the subsequent 20-m sprints was examined in both parts 1 and 2 (15 seconds, 4, 8, and 12 minutes). Fourteen (mean ± SD: age = 20.83 ± 1.26 years; height = 1.77 ± 0.04 m; and mass = 74.89 ± 6.07 kg) (part 1) and 15 (mean ± SD: age = 20.64 ± 1.00 years; height = 1.78 ± 0.06 m; and mass = 75.67 ± 6.28 kg) (part 2) male collegiate and club hurling players volunteered to participate. A randomized cross-over design was used to compare BDJ volumes (1, 2, and 3 sets of 3 repetitions) and BDJ intrarepetition recovery time (15 vs. 60 seconds) after a warm-up followed by 2 baseline 20-m sprints. The results in part 1 reported a significant improvement in 5- and 10-m sprint time for 1 set of 3 BDJs between baseline and 4 minutes (5 m: −2.34%, p = 0.04, effect size [ES] = −0.043; 10 m: −1.42%, p = 0.03, ES = −0.35), and baseline and 12 minutes (5 m: −3.33%, p = 0.03, ES = −0.57; 10 m: −2.13%, p = 0.01, ES = −0.52). Part 2 reported a significant improvement in 5-m sprint time between baseline and 15 seconds (5 m: −3.38%, p = 0.01, ES = −0.83; 10 m: −2.07%, p = 0.02, ES = −0.58) after the BDJs. The findings support the use of 1 set of 3 BDJs using a 15-second intrarepetition recovery period to maximize 5-, 10-, and 20-m sprint performance after 15 seconds of recovery after the final BDJ in hurling players. The acute response to this BDJ protocol proves to be time efficient and effective in acutely improving sprint acceleration
The 2018 Global Research Expedition on Altitude-related Chronic Health (REACH) to Cerro de Pasco, Peru: An Experimental Overview
Get PDFIn 2016, the international research team - Global Research Expedition onAltitude-related Chronic Health (REACH) - was established and executed a high altituderesearch expedition to Nepal. The team consists of ~45 students, principal investigatorsand physicians with the common objective of conducting experiments focused on highaltitude adaptation in lowlanders, and highlanders with lifelong exposure to high altitude.In 2018, Global REACH traveled to Peru where we performed a series of experiments inthe Andean highlanders. The experimental objectives, organization and characteristics,and key cohort data from Global REACH's latest research expedition are outlined herein.Herein, fifteen major studies are described that aimed to elucidate the physiologicaldifferences in high altitude acclimatization between lowlanders (n=30) and Andean bornhighlanders with (n=22) and without (n=45) Excessive Erythrocytosis (EE). Afterbaseline testing in Kelowna, BC, Canada (344m), Global REACH travelled to Lima, Peru(~80 m), and then ascended by automobile to Cerro de Pasco, Peru (~4300m) whereexperiments were conducted over 25 days. The core studies focused on elucidating themechanism(s) governing cerebral and peripheral vascular function, cardiopulmonaryregulation, exercise performance, and autonomic control. Despite encountering seriouslogistical challenges, each of the proposed studies were completed at both sea level andhigh altitude amounting to ~780 study sessions and >3000 hrs of experimental testing.Participant demographics and data related to acid-base balance and exercise capacityare presented. The collective findings will contribute to our understanding of howlowlanders and Andean highlanders have adapted under high altitude stress
Optimising care for patients with diabetic foot ulcers: overcoming the barriers
No full textThis article covers the key topics discussed during a symposium at the 15th Masterclass on the Foot in Diabetes UK (FDUK) Annual Conference held in Harrogate on November 5, 2019. This symposium, sponsored by Urgo Medical, aimed to provide practical information on optimising care for patients with diabetic foot ulcers (DFUs) and strategies to overcome the barriers that affect wound healing and service delivery. This symposium was presented by Benjamin Bullen and James Cowden and facilitated by Richard Shorney.
Richard Shorney kicked off the session on the topic of the current health landscape in the UK and the only factor that remains constant — which, paradoxically, is change. For example, there have been vast changes led by an in-depth review of funding and directed healthcare policies. In line with these changes, discussion was centred on how to overcome challenges facing service delivery of DFU care, including delays in referral to specialist foot care teams (Manu et al, 2018) and an increasing demand for clinical services (Guest et al, 2017).
The role and importance of business cases in supporting the development of clinical care, based on robust clinical evidence, were also highlighted. According to clinical evidence, in the field of DFU management, improving patient outcomes, increasing ulcer-free days and reducing healing time are achievable goals when the appropriate standard of care is provided
A biomechanical approach to evaluate overload and specificity characteristics within physical preparation exercises
Get PDFAn essential component of any physical preparation programme is the selection of training exercises to facilitate desired performance outcomes, with practitioners balancing the principles of sports training to inform exercise selection. This study aimed to advance biomechanical understanding of the principles of overload and specificity within exercise selection, utilising novel joint kinetic and intra-limb joint coordination analyses. Three-dimensional kinematic and kinetic data were obtained from six male sprinters (100 m PB, 10.64–11.00) performing block starts (competitive motor task) and seven training exercises that encompassed traditionally viewed general and more specific exercises. Results highlighted the challenging nature of exercise selection, with all exercises demonstrating capacity to overload relevant joint kinetic features of the block start. In addition, all exercises were able to promote the emergence of proximal and in-phase extension joint coordination patterns linked with block start execution, although traditionally viewed non-specific exercises elicited greater overall coordination similarity. The current research helps advance biomechanical understanding of overload and specificity within exercise selection, by demonstrating how exercise selection should not solely be based on perceived replication of a competitive motor task. Instead, practitioners must consider how the musculoskeletal determinants of performance are overloaded, in addition to promoting task specific coordination patterns
Determinants of successful possession in Elite Gaelic Football
Get PDFGame demands of Elite Men’s Gaelic Football (GF) are understudied and far from clear. This first study to investigate the performance outcomes for winners and losers in a complete Senior Inter-county championship (SFC) will analyse which characteristics of possession were more likely to lead to score. Possessions (n = 6,174) from all games in the 2016 SFC (n = 64) were analysed using Dartfish ConnectPlus 7.0. Wilcoxon signed-rank test identified statistical differences (p < 0.05) between 20 performance indicators for winning versus losing teams, while a binary logistic regression was used to model shot outcome in terms of process indicators; method of gaining possession, area possession is gained, number of passes and duration of each possession, on the outcome of the possession. Findings reveal winning teams had significantly more possessions, higher productivity and lower turnover rates than losers. Logistic regression highlighted that opposition kickouts, possession duration and area where possession commenced were associated with possession outcome
Signpost to the new normal: An evidence-based summary from the British Association for the Study of Community Dentistry
Get PDFThe British Association for the Study of Community Dentistry (BASCD) is the UK’s professional association for the science, philosophy and practice of promoting oral health in society. They work with – and support – partners to improve population oral health and reduce health inequalities. In this article, they address some of the questions arising during the COVID-19 pandemic and signpost readers to helpful evidence-based information sources, to assist in the return to work and the ‘new normal’
The influence of habitual endurance exercise on carotid artery strain and strain-rate in young and middle-aged men
Get PDFCentral arterial stiffness is an independent predictor of cardiovascular risk that can be modified by exercise training. However, conventional local measures of carotid artery stiffness display conflicting responses to habitual endurance exercise in young and older adults. 2D-Strain imaging of the common carotid artery (CCA) quantifies circumferential deformation (strain) of the arterial wall across the cardiac cycle, which is more sensitive at detecting age-related alterations in CCA stiffness than conventional methods. Therefore, the study was designed to examine the relationship between habitual endurance exercise (running) and CCA 2D-Strain parameters in young and middle-aged men. Short-axis ultrasound images of the CCA were obtained from 13 young nonrunners (23 years [95% CI: 21-26]), 19 young runners (24 [22-26]), 13 middle-aged nonrunners (54 [52-56]) and 19 middle-aged runners (56 [54-58]). Images were analysed for peak circumferential strain (PCS; magnitude of deformation) as well as systolic and diastolic strain-rate (S-SR and D-SR; deformation velocity) and group differences were examined via two-way ANOVA. PCS, S-SR and D-SR were attenuated in middle-aged males when compared to young men (all P ≤ 0.001). PCS and S-SR were elevated in young and middle-aged runners when compared to nonrunners (P = 0.002 and P =0.009 respectively), but no age*training status interaction was observed. In contrast, there was no influence of habitual running on D-SR. Habitual exercise is associated with comparable improvements in CCA 2D-Strain parameters in young and middle-aged men, but the age-related decline in PCS and S-SR may be more amenable to habitual endurance exercise than D-SR
The influence of barosensory vessel mechanics on the vascular sympathetic baroreflex: Insights into ageing and blood pressure homeostasis
Get PDFChanges in the arterial baroreflex arc contribute to elevated sympathetic outflow and altered reflex control of blood pressure with human ageing. Utilizing ultrasound and sympathetic microneurography (muscle sympathetic nerve activity; MSNA) we investigated the relationships between aortic and carotid artery wall tension (indices of baroreceptor activation) and the vascular sympathetic baroreflex operating point (OP; MSNA burst incidence) in healthy, normotensive young (n = 27, 23 ± 3 years) and middle-aged men (n = 22, 55 ± 4 years). In young men, the OP was positively related to the magnitude and rate of unloading and time spent unloaded in the aortic artery (r = 0.56, 0.65 and 0.51, P = 0.02, 0.003 and 0.03), but not related to the magnitude or rate of unloading or time spent unloaded in the carotid artery (r = -0.32, -0.07 and 0.06, P = 0.25, 0.81 and 0.85). In contrast, in middle-aged men, the OP was not related to either the magnitude or rate of unloading or time spent unloaded in the aortic (r = 0.22, 0.21 and 0.27, P = 0.41, 0.43 and 031) or carotid artery (r = 0.48, 0.28 and -0.01, P = 0.06, 0.25 and 0.98). In conclusion, in young men, aortic unloading mechanics may play a role in determining the vascular sympathetic baroreflex OP. In contrast, in middle-aged men, barosensory vessel unloading mechanics do not appear to determine the vascular sympathetic baroreflex OP, and therefore do not contribute to age-related arterial baroreflex resetting and increased resting MSNA.
KEYWORDS: muscle sympathetic nerve activity; barosensory vessel unloading mechanics; healthy ageing; sympathetic nervous system; baroreflex
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NEW AND NOTEWORTHY
We assessed the influence of barosensory vessel mechanics (magnitude and rate of unloading and time spent unloaded) as a surrogate for baroreceptor unloading.
In young men, aortic unloading mechanics are important in regulating the operating point of the vascular sympathetic baroreflex, whereas in middle-aged men, these arterial mechanics do not influence this operating point.
The age-related increase in resting muscle sympathetic nerve activity does not appear to be driven by altered baroreceptor input from stiffer barosensory vessels
Mentoring PE Student Teachers in Wales: Lessons from a Systematic Review of the Literature
Get PDFThis paper systematically reviews the contemporary research literature surrounding physical education (PE) mentors in initial teacher education (ITE). Using the ‘Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols’ (PRISMA-P) methodologies, articles were ana-lysed qualitatively using deductive thematic analysis in relation to content related to three core aspects of PE mentorship: i) terminology, ii) attributes and iii) professional learning. The findings identified variations in the ter-minology and the expectations associated with the role of the PE mentor. A significant number of research studies identified in the literature search focused on developing mentoring processes through collaboration and co-enquiry approaches. However, the literature review found a lack of explicit reference to the professional learning needs and opportunities for PE mentors. The review has led to six key recommendations, two of which are: i) PE mentors should be selected because they possess appropriate attributes to be effective in the role and, ii) professional learning opportu-nities should be made available to enable PE mentors to recognise the scope of the role and build their capacity to employ collaborative and enquiry-based approaches to supporting the development of student teachers
Within-species variation in OMV cargo proteins: the Myxococcus xanthus OMV pan-proteome
Get PDFExtracellular membrane vesicles are produced by all domains of life (bacteria, archaea and eukaryotes). Bacterial extracellular vesicles (outer membrane vesicles or OMVs) are produced by outer membrane blebbing, and contain proteins, nucleic acids, virulence factors, lipids and metabolites. OMV functions depend on their internal composition, therefore understanding the proteome of OMVs, and how it varies between organisms, is imperative. Here, we report a comparative proteomic profiling of OMVs from strains of Myxococcus xanthus, a predatory species of Gram-negative myxobacteria whose secretions include secondary metabolites and hydrolytic enzymes, thought to be involved in prey lysis. Ten strains were chosen for study, of which seven had genome sequences available. The remaining three strains were genome sequenced allowing definition of the core and accessory genes and genome-derived proteins found within the pan-genome and pan-proteome respectively. OMVs were isolated from each strain and proteins identified using mass spectrometry. The M. xanthus OMV pan-proteome was found to contain tens of ‘core’ and hundreds of ‘accessory’ proteins. Properties of the OMV pan-proteome were compared with those of the pan-proteome deduced from the M. xanthus pan-genome. On average, 80% of ‘core’ OMV proteins are encoded by genes of the core genome, yet the OMV proteomes of individual strains contain subsets of core genome-derived proteins which only partially overlap. In addition, the distribution of characteristics of vesicle proteins does not correlate with the genome-derived proteome characteristic distribution. We hypothesize that M. xanthus cells package a personalized subset of proteins whose availability is only partially dictated by the presence/absence of encoding genes within the genome