The Physiological and Perceptual Responses to Concurrent Training in Soccer Players

This thesis was designed to enhance our understanding of the acute responses to small-sided games (SSG) and their integration into a concurrent training program along with resistance training (RT) in soccer. The first study characterised the neuromuscular, biochemical, endocrine, and perceptual responses to SSG training over 24-hours. The SSG (4vs4+goalkeepers; 6x7-min; 2-min inter-set recovery) induced immediate fatigue which persisted until the following morning. However, neuromuscular function presented a bimodal recovery pattern, whereby there was a temporary recovery at 2 hours post. Therefore, it was determined that the performance of a secondary training session at 2 hours post may not be compromised. The second study compared the responses to a day consisting of SSG training (single), versus a day consisting of SSG plus RT 2 hours later (double). The double training session resulted in further small impairments in neuromuscular, perceptual, and endocrine markers at 24 hours post training. The third study manipulated the order of SSG and RT and compared the performance of training and the 24-hour responses. This study found that whilst there were significant within-day differences in neuromuscular and endocrine markers, there were no differences at 24 hours post training. Furthermore, the order of SSG and RT did not affect the performance of SSG, but perceived exertion during RT was higher when performed after SSG training. This thesis provides a series of novel findings that enhance our understanding of the responses to SSG, the effects of performing multiple daily training sessions, and the effects of training order in soccer

Measuring Recovery: An Adapted Brief Assessment of Mood (BAM+) Compared to Biochemical and Power Output Alterations

ObjectivesBiochemical (e.g., creatine kinase (CK)) and neuromuscular (e.g., peak power output (PPO)) markers of recovery are expensive and require specialist equipment. Perceptual measures are an effective alternative, yet most validated scales are too long for daily use.DesignThis study utilises a longitudinal multi-level design to test an adapted Brief Assessment of Mood (BAM + ), with four extra items and a 100 mm visual analogue scale to measure recovery.MethodsElite under-21 academy soccer players (N = 11) were monitored across five games with data (BAM+, CK and PPO) collected for each game at 24 hours pre, 24 hours and 48 hours post-match. Match activity data for each participant was also collected using GPS monitors on players.ResultsBAM+, CK and PPO had significant (p < .05) linear and quadratic growth curves across time and games that matched the known time reports of fatigue and recovery. Multi-level linear modelling (MLM) with random intercepts for ‘participant’ and ‘game’ indicated only CK significantly contributed to the variance of BAM+ scores (p < .05). Significant correlations (p < .01) were found between changes in BAM+ scores from baseline at 24 and 48 hours post-match for total distance covered per minute, high intensity distance covered per minute, and total number of sprints per minute.ConclusionsVisual and inferential results indicate that the BAM+ appears effective for monitoring longitudinal recovery cycles in elite level athletes. Future research is needed to confirm both the scales reliability and validity

Changes in acceleration and deceleration capacity throughout professional soccer match-play

As the acceleration and deceleration demands of soccer are currently not well understood, this study aimed to profile markers of acceleration and deceleration capacity during professional soccer match-play. This within-player observational study required reserve team players from a Premier League club to wear 10 Hz Global Positioning System units throughout competitive matches played in the 2013/2014 competitive season. Data is presented for players who completed four or more games during the season (n = 11) and variables are presented according to six 15 min intervals (I1-6: 00:00-14:59 min, 15:00-29:59 min, 30:00-44:59 min, 45:00-59:59 min, 60:00-74:59 min, 75:00-89:59 min). During I6, the distance covered (total, per minute, and at high intensity), number of sprints, accelerations (total and high intensity), decelerations (total and high intensity), and impacts were reduced compared to I1 (all P ≤ 0.05). The number of high intensity impacts remained unchanged throughout match-play (P > 0.05). These findings indicate that high intensity actions and markers of acceleration and deceleration capacity are reduced in the last 15 min of the normal duration of match-play. Such information can be used to increase the specificity of training programmes designed for soccer players while also giving further insight in to the effects of 90 min of soccer-specific exercise. Interventions that seek to maintain the acceleration and deceleration capacity of players throughout the full duration of a soccer match warrant investigation

Assessing activity participation in the ACL injured population: a systematic review of activity rating scale measurement properties

Background: Participation is an important factor in assessing both the requirement for and outcome from anterior cruciate ligament reconstruction. Many patient-reported rating scales exist; however, measurement properties have not been well established. Objective: To provide a systematic review to identify currently available activity rating scales for anterior cruciate ligament injured subjects and to evaluate current knowledge of their measurement properties. Methods: Systematic searches of four databases (Medline, AMED, EMBASE, and CINAHL) without date or language restriction, using terms structured around the PICOS system were completed on 1st March 2011. Citation tracking, reference screening and contact with lead authors of key papers completed the search strategy. Studies using participation rating scales were identified to assess frequency of reporting and cited validation. Studies assessing one or more psychometric properties of the identified rating scales were subject to independent data extraction and critical appraisal by two independent authors using published tools. Results: Thirty-one rating scales were identified from 241 outcome studies. Most scales were inadequately developed or validated prior to use. Only three scales (Tegner, CSAS, and Marx) had psychometric analysis in eight studies of mixed quality. Only the Tegner scale has adequate assessment of reliability, validity, and responsiveness. The use of type, intensity, and frequency variables in the identified scales is discussed. Conclusions: The Tegner scale has been adequately validated; however, other rating scales require further validation. A comprehensive comparative analysis of clinical applicability and psychometric testing of existing scales, including clinically useful statistics, is required

Spinal position sense and trunk muscle activity during sitting and standing in non-specific chronic low back pain: classification analysis

Study Design. A cross-sectional study between subgroups of nonspecific chronic low back pain (NSCLBP) and asymptomatic controls. Objective. To investigate NSCLBP subgroup differences in spinal position sense and trunk muscle activity when repositioning thoracic and lumbar spine into neutral (midrange) spinal position during sitting and standing. Summary of Background Data. Patients with NSCLBP report aggravation of symptoms during sitting and standing. Impaired motor control in NSCLBP, associated with sitting and standing postures nearer the end range of spinal motion, may be a contributing factor. Rehabilitation improving neutral (midrange) spinal position control is advocated. Postural and motor control alterations vary in different NSCLBP subgroups, potentially requiring specific postural interventions. There is limited evidence on whether subgroup differences exist when performing neutral spine position tasks. Methods. Ninety patients with NSCLBP and 35 asymptomatic controls were recruited. Two blinded practitioners classified NSCLBP into subgroups of active extension pattern and flexion pattern. Participants were assisted into neutral spine position and asked to reproduce this position 4 times. Absolute, variable, and constant errors were calculated. Three-dimensional thoracic and lumbar kinematics quantified the repositioning accuracy and surface electromyography assessed back and abdominal muscles activity bilaterally. Results. Irrespective of subclassification, patients with NSCLBP produced significantly greater error magnitude and variability than the asymptomatic controls, but subgroup differences were detected in the error direction. Subgroup differences in the trunk muscle activity were not consistently identified. Although both subgroups produced significantly higher abdominal activity, subclassification revealed difference in superficial multifidus activity during standing, with flexion pattern producing significantly greater activity than the asymptomatic controls. Conclusion. Subgroups of NSCLBP had similar neutral spinal position deficits regarding error magnitude and variability, but subclassification revealed clear subgroup differences in the direction of the deficit. The trunk muscle activation was shown to be largely nondiscriminatory between subgroups, with the exception of superficial lumbar multifidus

Neuromuscular, biochemical, endocrine, and mood responses to small-sided games' training in professional soccer

The 24h responses to small-sided games (SSG) soccer training were characterized. Professional soccer players (n=16) performed SSG’s (4vs4 + goalkeepers; 6x7-min, 2-min inter-set recovery) with performance (peak-power output, PPO; jump height, JH), physiological (blood creatine kinase: CK, lactate; salivary testosterone, cortisol), and mood measures collected before (baseline), and after (immediately; 0h, +2h, +24h). For PPO and JH, possibly small-moderate reductions occurred at 0h (-1.1W·kg-1; ±0.9W·kg-1, -3.2cm; ±1.9cm, respectively), before returning to baseline at +2h (trivial) and declining thereafter (small-moderate effect) at +24h (-0.9W·kg-1; ±0.8W·kg-1, -2.5cm; ±1.2cm, respectively). Lactate increased at 0h (likely-large; +1.3mmol·L-1; ±0.5mmol·L-1), reduced at +2h (likely-small; -0.5mmol·L-1; ±0.2mmol·L-1), and returned to baseline at 24h (trivial). A very-likely small increase in CK occurred at 0h (+97u·L-1; ±28u·L-1), persisting for +24h (very-likely small; +94u·L-1; ±49u·L-1). Possibly-small increases in testosterone (+20pg·ml-1; ±29pg·ml-1) occurred at 0h, before likely-moderate declines at +2h (-61pg·ml-1; ±21pg·ml-1) returning to baseline at +24h (trivial). For cortisol, possibly-small decreases occurred at 0h (-0.09ug·dl-1; -±0.16ug·dl-1), before likely-large decreases at +2h (-0.39ug·dl-1; ±0.12ug·dl-1), which persisted for 24h (likely-small; -0.12ug·dl-1; ±0.11ug·dl-1). Mood was disturbed by SSG’s at 0h (likely-moderate; +13.6AU, ±5.6AU) and +2h (likely-small; +7.9AU; ±5.0AU), before returning to baseline at +24h (trivial). The movement demands of SSG’s result in a bimodal recovery pattern of neuromuscular function and perturbations in physiological responses and mood for up to 24h. Accordingly, when programming soccer training, SSG’s should be periodized throughout the competitive week with submaximal technical/tactical activities

Photonic Sorting of Aligned, Crystalline Carbon Nanotube Textiles

Floating catalyst chemical vapor deposition uniquely generates aligned carbon nanotube (CNT) textiles with individual CNT lengths magnitudes longer than competing processes, though hindered by impurities and intrinsic/extrinsic defects. We present a photonic-based post-process, particularly suited for these textiles, that selectively removes defective CNTs and other carbons not forming a threshold thermal pathway. In this method, a large diameter laser beam rasters across the surface of a partly aligned CNT textile in air, suspended from its ends. This results in brilliant, localized oxidation, where remaining material is an optically transparent film comprised of few-walled CNTs with profound and unique improvement in microstructure alignment and crystallinity. Raman spectroscopy shows substantial D peak suppression while preserving radial breathing modes. This increases the undoped, specific electrical conductivity at least an order of magnitude to beyond that of single-crystal graphite. Cryogenic conductivity measurements indicate intrinsic transport enhancement, opposed to simply removing nonconductive carbons/residual catalyst

Characterization of diverse bacteriohopanepolyols in a permanently stratified, hyper-euxinic lake

Bacteriohopanepolyols (BHPs) are a diverse class of bacterial lipids that hold promise as biomarkers of specific microbes, microbial processes, and environmental conditions. BHPs have been characterized in a variety of terrestrial and aquatic environments, but less is known about their distribution and abundance in extreme environmental systems. In the present study, samples taken from the water column and upper sediments of the hyper-euxinic, meromictic Mahoney Lake (Canada) were analyzed for BHPs. Analyses show distinct BHP distributions within the oxic mixolimnion, the chemocline, and the euxinic monimolimnion. Bacteriohopanetetrol (BHT) and unsaturated BHT are the dominant BHPs found in the oxic mixolimnion and at the chemocline, whereas a novel BHP (tentatively identified as diunsaturated aminotriol) dominates the euxinic monimolimnion. Along with the novel BHP structure, composite BHPs (i.e., BHT-cyclitol ether and BHT-glucosamine) were observed in the euxinic monimolimnion and sediments, indicating their production by anaerobic bacteria. Complementary metagenomic analysis of genes involved in BHP biosynthesis (i.e., shc, hpnH, hpnO, hpnP, and hpnR) further revealed that BHPs in Mahoney Lake are most likely produced by bacteria belonging to Deltaproteobacteria, Chloroflexi, Planctomycetia, and Verrucomicrobia. The combined observations of BHP distribution and metagenomic analyses additionally indicate that 2- and 3-methyl BHTs are produced within the euxinic sediments in response to low oxygen and high osmotic concentrations, as opposed to being diagnostic biomarkers of cyanobacteria and aerobic metabolisms

Screening of healthcare workers for SARS-CoV-2 highlights the role of asymptomatic carriage in COVID-19 transmission.

Significant differences exist in the availability of healthcare worker (HCW) SARS-CoV-2 testing between countries, and existing programmes focus on screening symptomatic rather than asymptomatic staff. Over a 3 week period (April 2020), 1032 asymptomatic HCWs were screened for SARS-CoV-2 in a large UK teaching hospital. Symptomatic staff and symptomatic household contacts were additionally tested. Real-time RT-PCR was used to detect viral RNA from a throat+nose self-swab. 3% of HCWs in the asymptomatic screening group tested positive for SARS-CoV-2. 17/30 (57%) were truly asymptomatic/pauci-symptomatic. 12/30 (40%) had experienced symptoms compatible with coronavirus disease 2019 (COVID-19)>7 days prior to testing, most self-isolating, returning well. Clusters of HCW infection were discovered on two independent wards. Viral genome sequencing showed that the majority of HCWs had the dominant lineage B∙1. Our data demonstrates the utility of comprehensive screening of HCWs with minimal or no symptoms. This approach will be critical for protecting patients and hospital staff.This work was supported by the Wellcome Trust Senior Research Fellowships 108070/Z/15/Z to MPW, 215515/Z/19/Z to SGB and 207498/Z/17/Z to IGG; Collaborative award 206298/B/17/Z to IGG; Principal Research Fellowship 210688/Z/18/Z to PJL; Investigator Award 200871/Z/16/Z to KGCS; Addenbrooke’s Charitable Trust (to MPW, SGB, IGG and PJL); the Medical Research Council (CSF MR/P008801/1 to NJM); NHS Blood and Transfusion (WPA15-02 to NJM); National Institute for Health Research (Cambridge Biomedical Research Centre at CUHNFT), to JRB, MET, AC and GD, Academy of Medical Sciences and the Health Foundation (Clinician Scientist Fellowship to MET), Engineering and Physical Sciences Research Council (EP/P031447/1 and EP/N031938/1 to RS),Cancer Research UK (PRECISION Grand Challenge C38317/A24043 award to JY). Components of this work were supported by the COVID-19 Genomics UK Consortium, (COG-UK), which is supported by funding from the Medical Research Council (MRC) part of UK Research & Innovation (UKRI), the National Institute of Health Research (NIHR) and Genome Research Limited, operating as the Wellcome Sanger Institut

Superspreaders drive the largest outbreaks of hospital onset COVID-19 infections.

SARS-CoV-2 is notable both for its rapid spread, and for the heterogeneity of its patterns of transmission, with multiple published incidences of superspreading behaviour. Here, we applied a novel network reconstruction algorithm to infer patterns of viral transmission occurring between patients and health care workers (HCWs) in the largest clusters of COVID-19 infection identified during the first wave of the epidemic at Cambridge University Hospitals NHS Foundation Trust, UK. Based upon dates of individuals reporting symptoms, recorded individual locations, and viral genome sequence data, we show an uneven pattern of transmission between individuals, with patients being much more likely to be infected by other patients than by HCWs. Further, the data were consistent with a pattern of superspreading, whereby 21% of individuals caused 80% of transmission events. Our study provides a detailed retrospective analysis of nosocomial SARS-CoV-2 transmission, and sheds light on the need for intensive and pervasive infection control procedures