Athlete-tracking devices that include global positioning system (GPS) and microelectrical mechanical system (MEMS) components are now commonplace in sport research and practice. These devices provide ...large amounts of data that are used to inform decision making on athlete training and performance. However, the data obtained from these devices are often provided without clear explanation of how these metrics are obtained. At present, there is no clear consensus regarding how these data should be handled and reported in a sport context. Therefore, the aim of this review was to examine the factors that affect the data produced by these athlete-tracking devices and to provide guidelines for collecting, processing, and reporting of data. Many factors including device sampling rate, positioning and fitting of devices, satellite signal, and data-filtering methods can affect the measures obtained from GPS and MEMS devices. Therefore researchers are encouraged to report device brand/model, sampling frequency, number of satellites, horizontal dilution of precision, and software/firmware versions in any published research. In addition, details of inclusion/exclusion criteria for data obtained from these devices are also recommended. Considerations for the application of speed zones to evaluate the magnitude and distribution of different locomotor activities recorded by GPS are also presented, alongside recommendations for both industry practice and future research directions. Through a standard approach to data collection and procedure reporting, researchers and practitioners will be able to make more confident comparisons from their data, which will improve the understanding and impact these devices can have on athlete performance.
To quantify the seasonal training load completed by professional soccer players of the English Premier League.
Thirty players were sampled (using GPS, heart rate, and rating of perceived exertion ...RPE) during the daily training sessions of the 2011-12 preseason and in-season period. Preseason data were analyzed across 6×1-wk microcycles. In-season data were analyzed across 6×6-wk mesocycle blocks and 3×1-wk microcycles at start, midpoint, and end-time points. Data were also analyzed with respect to number of days before a match.
Typical daily training load (ie, total distance, high-speed distance, percent maximal heart rate %HRmax, RPE load) did not differ during each week of the preseason phase. However, daily total distance covered was 1304 (95% CI 434-2174) m greater in the 1st mesocycle than in the 6th. %HRmax values were also greater (3.3%, 1.3-5.4%) in the 3rd mesocycle than in the first. Furthermore, training load was lower on the day before match (MD-1) than 2 (MD-2) to 5 (MD-5) d before a match, although no difference was apparent between these latter time points.
The authors provide the 1st report of seasonal training load in elite soccer players and observed that periodization of training load was typically confined to MD-1 (regardless of mesocycle), whereas no differences were apparent during MD-2 to MD-5. Future studies should evaluate whether this loading and periodization are facilitative of optimal training adaptations and match-day performance.
The current version of the Human Disease Ontology (DO) (http://www.disease-ontology.org) database expands the utility of the ontology for the examination and comparison of genetic variation, ...phenotype, protein, drug and epitope data through the lens of human disease. DO is a biomedical resource of standardized common and rare disease concepts with stable identifiers organized by disease etiology. The content of DO has had 192 revisions since 2012, including the addition of 760 terms. Thirty-two percent of all terms now include definitions. DO has expanded the number and diversity of research communities and community members by 50+ during the past two years. These community members actively submit term requests, coordinate biomedical resource disease representation and provide expert curation guidance. Since the DO 2012 NAR paper, there have been hundreds of term requests and a steady increase in the number of DO listserv members, twitter followers and DO website usage. DO is moving to a multi-editor model utilizing Protégé to curate DO in web ontology language. This will enable closer collaboration with the Human Phenotype Ontology, EBI's Ontology Working Group, Mouse Genome Informatics and the Monarch Initiative among others, and enhance DO's current asserted view and multiple inferred views through reasoning.
The purpose of the present study was to examine the influence of workload prior to injury on injury (tissue type and severity) in professional soccer players. Twenty-eight days of retrospective ...training data prior to non-contact injuries (n=264) were collated from 192 professional soccer players. Each injury tissue type (muscle, tendon and ligament) and severity (days missed) were categorised by medical staff. Training data were recorded using global positioning system (GPS) devices for total distance (TD), high speed distance (HSD,>5.5 m/s
), and sprint distance (SPR,>7.0 m/s
). Accumulated 1, 2, 3, 4-weekly loads and acute:chronic workload ratios (ACWR) (coupled, uncoupled and exponentially weighted moving average (EWMA) approaches) were calculated. Workload variables and injury tissue type were compared using a one-way ANOVA. The association between workload variables and injury severity were examined using a bivariate correlation. There were no differences in accumulated weekly loads and ACWR calculations between muscle, ligament, and tendon injuries (P>0.05). Correlations between each workload variable and injury severity highlighted no significant associations (P>0.05). The present findings suggest that the ability of accumulated weekly workload or ACWR methods to differentiate between injury type and injury severity are limited using the present variables.
Submission grappling consists of skills and movements used in combat sports to physically control opponents whilst trying to apply choke holds and joint locks. There is currently no accepted method ...of monitoring external load in grappling-based sports due to the absence of key variables such as distance, velocity or time. The primary aim of this study was to determine whether PlayerLoad is a reliable variable for measuring external load of submission grappling movements, with a secondary aim of determining the between repetition variance of submission grappling movements. 7 experienced submission grapplers were recruited. Each wore a torso mounted Catapult
Optimeye S5 microelectromechanical systems (MEMS) device and completed 5 repetitions of each of the following: 4 submission techniques; 5 transition techniques; 2 guard pass techniques; 2 takedown techniques. Accumulated PlayerLoad (PLd
) was recorded as a marker of absolute load, with accumulated PlayerLoad per minute (PLd
∙min
) representing relative load. Reliability of each was assessed using intraclass correlation coefficient (ICC
) (≥ 0.70). Between repetition movement variation was assessed via coefficient of variation with 95% confidence intervals (CV, 95%CI) (acceptable ≤ 15%, good ≤ 10%). PLd
ICC
range = 0.78-0.98, with CV range = 9-22%. PLd
∙min
ICC
range = 0.83-0.98, with CV range = 11-19%. Though several variables displayed CV > 15%, all had 95%CI lower boundaries ≤ 15%. Whilst PlayerLoad was found to be a reliable measure for submission grappling, relatively high CVs across most techniques examined suggest PlayerLoad may not be appropriate for measuring changes in external load for individual movements in submission grappling. However, it may prove a useful tool for monitoring the external load of full, grappling-based, training sessions within an individual.
•Estimates of players’ maturity status should be taken every 3–4 months during an annual season, with a focus on players approaching and during peak height velocity.•Key stakeholders should be ...educated about maturation and peak height velocity, particularly in relation to the potential use of bio-banding strategies.•Clear lines of communication should be established with key stakeholders in order to identify the volume of weekly physical activity each child is engaged in.•The prediction error embroiled within each maturity-estimation equation should be considered, along with the implications of additional errors imposed by spurious anthropometric measurements (i.e., self-reported birth-parent stature).•Key stakeholders should be aware of the increased risk of injuries owing to inappropriate training loads across peak height velocity.
Biological maturation can be defined as the timing and tempo of progress to achieving a mature state. The estimation of age of peak height velocity (PHV) or percentage of final estimated adult stature attainment (%EASA) is typically used to inform the training process in young athletes. In youth soccer, maturity-related changes in anthropometric and physical fitness characteristics are diverse among individuals, particularly around PHV. During this time, players are also at an increased risk of sustaining an overuse or growth-related injury. As a result, the implementation of training interventions can be challenging. The purpose of this review was to (1) highlight and discuss many of the methods that can be used to estimate maturation in the applied setting and (2) discuss the implications of manipulating training load around PHV on physical development and injury risk. We have provided key stakeholders with a practical online tool for estimating player maturation status (Supplementary Maturity Estimation Tools). Whilst estimating maturity using predictive equations is useful in guiding the training process, practitioners should be aware of its limitations. To increase the accuracy and usefulness of data, it is also vital that sports scientists implement reliable testing protocols at predetermined time-points.
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Mealtime insulin is commonly added to manage hyperglycemia in type 2 diabetes when basal insulin is insufficient. However, this complex regimen is associated with weight gain and hypoglycemia. This ...study compared the efficacy and safety of exenatide twice daily or mealtime insulin lispro in patients inadequately controlled by insulin glargine and metformin despite up-titration.
In this 30-week, open-label, multicenter, randomized, noninferiority trial with 12 weeks prior insulin optimization, 627 patients with insufficient postoptimization glycated hemoglobin A1c (HbA1c) were randomized to exenatide (10-20 µg/day) or thrice-daily mealtime lispro titrated to premeal glucose of 5.6-6.0 mmol/L, both added to insulin glargine (mean 61 units/day at randomization) and metformin (mean 2,000 mg/day).
Randomization HbA1c and fasting glucose (FG) were 8.3% (67 mmol/mol) and 7.1 mmol/L for exenatide and 8.2% (66 mmol/mol) and 7.1 mmol/L for lispro. At 30 weeks postrandomization, mean HbA1c changes were noninferior for exenatide compared with lispro (-1.13 and -1.10%, respectively); treatment differences were -0.04 (95% CI -0.18, 0.11) in per-protocol (n = 510) and -0.03 (95% CI -0.16, 0.11) in intent-to-treat (n = 627) populations. FG was lower with exenatide than lispro (6.5 vs. 7.2 mmol/L; P = 0.002). Weight decreased with exenatide and increased with lispro (-2.5 vs. +2.1 kg; P < 0.001). More patients reported treatment satisfaction and better quality of life with exenatide than lispro, although a larger proportion of patients with exenatide experienced treatment-emergent adverse events. Exenatide resulted in fewer nonnocturnal hypoglycemic episodes but more gastrointestinal adverse events than lispro.
Adding exenatide to titrated glargine with metformin resulted in similar glycemic control as adding lispro and was well tolerated. These findings support exenatide as a noninsulin addition for patients failing basal insulin.
The brain can utilise medium chain triglycerides (MCTs) as an alternative fuel to glucose, and research has shown that MCT ingestion improves cognitive function in diseased and/or elderly ...individuals. The aim of this study is to determine if these improvements can also be observed in young, healthy adults. Furthermore, we aim to establish the ideal dosage and timeframe necessary for an effect.
Participants were divided equally into three groups of 10 (Placebo (0 g), 12 g and 18 g MCT/day) and were supplemented for 4 weeks. The supplement had a C
:C
ratio of 30:70. Participants visited the laboratory once a week for 5 weeks (baseline, test weeks 1-4) to undergo a battery of cognitive tests; Trail Making, Digit Span, Spatial Span, Covert Shift of Attention, and Rapid Visual Information Processing.
After 2-3 weeks of supplementation, MCT ingestion enhanced performance in cognitive tasks, including: Trail Making A/B and Digit Span Forwards/Backwards (ps<0.001) when compared to a placebo group taking a carbohydrate gel. In Spatial Span Backwards, there was a significant main effect of group (p = 0.002). Where significance was seen, there were main effects of time after 2-3 weeks (ps<0.05). There was minimal difference between the two MCT intervention groups in most measures (ps>0.05). There were also null results in tasks measuring attention and reaction time (ps>0.05).
MCT ingestion improved cognitive performance after 2-3 weeks, with minimal difference between taking 12 g and 18 g MCT/day groups, suggesting a possible dose-response threshold at 12 g MCT/day when supplementing over a short period.
Sport science has gained vast popularity with students who have an interest in both physiology and the underpinning mechanisms of exercise concerning performance and health. The high numbers of ...graduates each year, coupled with the low number of graduate positions working in sports, has led to a high level of competition between students. To stand out from the crowd, sport science students may undertake an internship placement as part of their course, designed to enhance theoretical, practical, and soft skills in an applied setting. In the present article, we highlight some of the positives and negatives of sport science internships and ways in which they can be implemented and facilitated. Suggestions have also been provided to make students more aware of the reality of working in professional sports, which includes awareness of the potential for long and unsociable hours of work.
•Combined the effects of MCT supplementation and exercise on cognitive performance.•Backed up previous literature that MCTs improve cognitive performance at rest.•Discovered MCTs offset the cognitive ...decline associated with a prolonged bout of exercise.•Used MCT gels with a combination of C8 and C10.
Prolonged exercise has been linked to a decline in cognitive function due to a variety of factors, such as a drop in oxygen in the prefrontal cortex and an increase in stress hormones and neurotransmitters. Medium chain triglycerides (MCTs) may possibly offset this decline as they provide energy for the brain via both direct and indirect pathways, alongside promoting chronic physiological adaptations within the brain.
Participants were divided into two groups; MCT (n = 9) and Placebo (n = 10). The MCT gels contained 6 g of MCT with a C8:C10 ratio of 30:70, whereas the placebo gels contained carbohydrates of similar calorific value to the MCT gels. Participants visited the laboratory on three occasions (familiarisation/fitness test, pre-supplementation, post-supplementation), during which they performed a battery of cognitive tasks assessing domains such as processing speed, working memory, selective attention, decision making and coordination, before and after a prolonged bout of exercise (60 mins at 90% gas exchange threshold (GET). A 2-week supplementation period between visits 2 and 3 involved the ingestion of 2 gels per day.
Exercise resulted in detriments in most cognitive tasks pre-supplementation for both groups, and post-supplementation for the Placebo group (main effect ps< 0.05). Post-supplementation, the effect of exercise was mediated in the MCT group for all cognitive tasks (main effect ps< 0.05), except for the Digit and Spatial Span Backwards test phases (main effect ps> 0.05). Furthermore, MCT supplementation enhanced before-exercise cognitive performance and in some measures, such as working memory, this was maintained after-exercise (interaction effect ps> 0.05).
Chronic MCT supplementation enhanced before-exercise cognitive performance and offset the cognitive decline caused by a prolonged bout of exercise. In some cases, improvements in before-exercise cognitive performance were maintained after-exercise.
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