Methods to predict the timing and status of biological maturation in male adolescent soccer players: A narrative systematic review.

The aim of this review was to summarise the methods used to predict and assess maturity status and timing in adolescent, male, academy soccer players. A systematic search was conducted on PubMed, Scopus, Web of Science, CINAHL, Medline and SPORTDiscus. Only experimental studies including male, academy players aged U9-U18 years registered with a professional soccer club were included. The methodological quality of the included studies was assessed using guidelines from the Framework of Potential Biases. Fifteen studies fulfilled our inclusion criteria. Studies were mainly conducted in European countries (n = 12). In total, 4,707 players were recruited across all 15 studies, with an age range of 8-18 years. Five studies were longitudinal, two studies were mixed-method designs and eight studies were cross-sectional. Due to high heterogeneity within the studies, a meta-analysis was not performed. Our findings provided no equivalent estimations of adult height, skeletal age, or age at PHV. Discrepancies were evident between actual and predicted adult height and age at PHV. The Bayley-Pinneau [1952], Tanner-Whitehouse 2 [1983] and Khamis-Roche [1994] methods produced estimates of adult height within 1cm of actual adult height. For age at PHV, both Moore [2015] equations produced the closest estimates to actual age at PHV, and the Fransen [2018] equation correlated highly with actual age at PHV (>90%), even when the period between chronological age and age at PHV was large. Medical imaging techniques (e.g., Magnetic Resonance Imaging, X-Ray, Dual energy X-ray Absorptiometry) demonstrated high intra/inter-rater reliability (ICC = 0.83-0.98) for skeletal maturity assessments. The poor concordance between invasive and non-invasive methods, is a warning to practitioners to not use these methods interchangeably for assessing maturational status and timing in academy soccer players. Further research with improved study designs is required to validate these results and improve our understanding of these methods when applied in this target population.

GP led medical student visits to primary schools can provide a valuable learning experience for both students and pupils.

Background: A key clinical skill for undergraduate medical students is communication with children, yet it is becoming increasingly difficult for medical schools to provide sufficient experience within a secondary care setting. One potential solution to this is to develop innovative ways of involving local schools.Aim: To demonstrate what was learned from a pilot school visit and show how this was developed into a successful programme.Method: As part of their GP-based Foundations of Primary Care course, medical students were allocated to local primary schools in their tutorial groups led by their GP tutors. They developed and delivered health promotion activities that were appropriate for school pupils. Review of the visit identified areas of improvement which were used to redesign the programme. Surveys were conducted after the subsequent visit to assess the response of medical students, school pupils and teachers.Learning outcomes: Medical students gained experience in communicating and interacting with school-aged children, and developed teaching and team working skills. School pupils reported change in their health-related knowledge and behaviour and the visits introduced them to the medical profession at a young age. The visits were well received by the teachers who valued the medical students' input.Conclusions: Building on the learning from the pilot school visit, a successful programme was developed that was challenging but ultimately enhanced medical student learning and brought significant benefits for the school pupils. Future developments include the potential to expand the topics taught and developing training in teaching for medical students.

Seasonal training and match load and micro-cycle periodization in male Premier League academy soccer players.

We quantified on pitch external loading of English Premier League (EPL) academy soccer players (n=76; U12-U18 age groups) over an entire competitive season. Mean accumulative weekly duration and total distance, respectively, was similar in the U12 (329±29 min; 19.9±2.2 km), U13 (323±29 min; 20.0±2.0 km) and U14 (339±25 min; 21.7±2.0 km; P>0.05 for all comparisons) age-groups, though all teams were less than U15 (421±15 min; 26.2±2.1 km), U16 (427±20 min; 25.9±2.5 km) and U18 (398±30 min; 26.1±2.6 km) players (P<0.05 for all comparisons). Mean weekly high-speed running and sprint distance was not different between U12 (220±95 m and 6±9 m respectively), U13 (331±212 m and 6±27 m) and U14 (448±193 m and 21±29 m) age-groups (P>0.05 for all pairwise comparisons) though all squads were less than U15 (657±242 m and 49±98 m), U16 (749±152 m and 95±55 m) and U18 (979±254 m and 123±56 m) age-groups (P<0.05 for all pairwise comparisons). Data demonstrate that absolute weekly training volume in EPL academy soccer players increases throughout the academy pathway. Furthermore, although U16-U18 players are capable of achieving similar training and match volumes as previously reported in adult EPL players, they do not yet achieve the absolute intensities of adult EPL players.

Energy Requirements of Male Academy Soccer Players from the English Premier League.

PURPOSE: This study aimed to inform the energy requirements of highly trained adolescent soccer players. Total energy expenditure (TEE) was quantified in academy soccer players from the English Premier League (EPL). METHODS: Twenty-four male adolescent soccer players from an EPL academy (under (U) 12/13 (U12/13), n = 8; U15, n = 8; U18, n = 8) were assessed for baseline maturity (maturity offset), body composition (dual-energy x-ray absorptiometry), and resting metabolic rate (indirect calorimetry). Subsequently, TEE, energy intake (EI) and physical loading patterns were assessed over a 14-d in-season period using doubly labeled water, the remote food photographic method, and global positioning system technology, respectively. RESULTS: U18 players presented with greater resting metabolic rate (2236 ± 93 kcal·d) and TEE (3586 ± 487 kcal·d; range, 2542-5172 kcal·d) than did both U15 (2023 ± 162 and 3029 ± 262 kcal·d, respectively; TEE range, 2738-3726 kcal·d) and U12/13 players (1892 ± 211 and 2859 ± 265 kcal·d, respectively; TEE range, 2275-3903 kcal·d; all, P < 0.01), although no difference in TEE was apparent between the U12/13 and U15 age groups. Fat-free mass was significantly different between all comparisons in a hierarchal manner (U18: 57.2 ± 6.1 kg > U15: 42.9 ± 5.8 kg > U12/13: 31.1 ± 3.5 kg; all, P < 0.01). Within age groups, no differences were apparent between EI and TEE (U12/13: -29 ± 277 kcal·d, P = 0.78; U15: -134 ± 327 kcal·d, P = 0.28; U18: -243 ± 724 kcal·d, P = 0.37), whereas U18 players (3180 ± 279 kcal·d) reported higher EI than did both U15 (2821 ± 338 kcal·d; P = 0.05) and U12/13 players (2659 ± 187 kcal·d; P < 0.01). CONCLUSIONS: The TEE of male academy soccer players progressively increase as players progress through the academy age groups. In some individuals (evident in all age groups), TEE was greater than that previously observed in adult EPL soccer players.

'GP Live'- recorded General Practice consultations as a learning tool for junior medical students faced with the COVID-19 pandemic restrictions.

BACKGROUND: First year medical students value doctor and patient contact. However, it can be challenging to achieve positive exposure to primary care on a large scale. The COVID-19 pandemic has placed even greater pressure on placing students in General Practice (GP). AIM: To assess the feasibility and acceptability of showing Year 1 medical students authentic recorded consultations between GPs and patients, and then explore what they gained from this. METHOD: Using Panopto® Video Platform, we pre-recorded real Primary Care consultations, with patient and GP consent, which were then processed securely using the University of Aberdeen server. These were shown to all Year 1 medical students who immediately debriefed these consultations in small groups with a GP tutor. Subsequently two focus groups were held with 11 students to evaluate what they had learnt. LEARNING OUTCOMES: The consultations were easy to record and play during the teaching session, although there were some issues with sound quality. All students in the focus groups enjoyed the experience. They gained new knowledge about the skills of GPs, and recognised GPs as positive role models. Students were able to identify a variety of communication and consultation skills used by the GP, which reinforced their teaching on these delivered elsewhere in the course. CONCLUSION: Using pre-recorded consultations as a teaching tool is reproducible, time-efficient and beneficial to students. We propose that this model of using authentic 'live' interactions between GPs and patients represents a valuable undergraduate educational opportunity and could be utilised by medical schools internationally.

Cross-sectional comparison of body composition and resting metabolic rate in Premier League academy soccer players: Implications for growth and maturation.

For the first time we aimed to: (1) assess fat-free mass (FFM) and RMR in youth soccer players, (2) compare measured RMR to estimated RMR using previously published prediction equations, and (3) develop a novel population-specific prediction equation. In a cross-sectional design, 99 males from a Premier League academy underwent assessments of body composition (DXA) and RMR (indirect-calorimetry). Measured RMR was compared to estimated values from five prediction equations. A novel RMR prediction equation was developed using stepwise multiple regression. FFM increased (P<0.05) between U12 (31.6±4.2 kg) and U16 (56.3±5.3 kg) after which no further increases occurred (P>0.05). RMR in the U12s (1655±195 kcal.day-1), U13s (1720±205 kcal.day-1) and U14s (1846±218kcal.day-1) was significantly lower than the U15s (1957±128 kcal.day-1), U16s (2042±155 kcal.day-1), U18s (1875±180 kcal.day-1) and U23s (1941±197 kcal.day-1) squads (P>0.05). FFM was the single best predictor of RMR (r2=0.43; P<0.01) and was subsequently included in the novel prediction equation: RMR (kcal.day-1) = 1315 + (11.1 x FFM in kg). Both FFM and RMR increase from 12-16 years old, thus highlighting the requirement to adjust daily energy intake to support growth and maturation. The novel prediction RMR equation developed may help to inform daily energy requirements.

Impact of acute rejection episodes on long-term graft survival following simultaneous kidney-pancreas transplantation.

Although it is well established that acute rejection is one of the major risk factors for chronic graft loss following kidney transplantation, its effect on long-term graft survival following simultaneous kidney-pancreas transplants (SKPTs) is less well known. We analyzed a large cohort of SKPTs and cadaver kidney transplants reported to the United Network for Organ Sharing database during 1988-97, to determine the impact of acute rejection episodes on long-term kidney and pancreas graft survival. Only patients whose kidney and pancreas grafts had survived for at least 1 year were included. Other potential risk factors influencing long-term graft survival were included in the analysis. Of the 4251 SKPTs, 45% had no acute rejection, 36% had kidney only rejection, 3% had pancreas only rejection, and 16% had both kidney and pancreas rejection within the 1st year post transplant. The 5-year kidney and pancreas graft survival rates adjusted for other risk factors were 91% and 85%, respectively; for those with no acute rejection episodes, 88% and 84%, respectively; for those with kidney only rejection, 94% and 83%, respectively; for those with pancreas only rejection; and 86% and 78%, respectively, for those with both kidney and pancreas rejection. The relative risk (RR) of kidney graft failure was 1.32 when acute rejection involved the kidney graft only, while the RR was 1.53 when the rejection involved both organs. We conclude that acute rejection episodes have a negative impact on the long-term kidney graft survival in the SKPT population similar to that in the cadaver kidney transplant population. Patients who had acute rejection episodes of both kidney and pancreas have the worst long-term graft survival.

Some numerical aspects of the training problem for feed-forward neural nets.

This paper considers the feed-forward training problem from the numerical point of view, in particular the conditioning of the problem. It is well known that the feed-forward training problem is often ill-conditioned; this affects the behaviour of training algorithms, the choice of such algorithms and the quality of the solutions achieved. A geometric interpretation of ill-conditioning is explored and an example of function approximation is analysed in detail.