Training experience as a limiting factor in master long distance runners

En las últimas décadas ha aumentado el número de atletas veteranos en carreras populares de resistencia. El estudio, que incluyó 103 atletas, tuvo el objetivo de analizar cómo influye la edad y los años de experiencia en el rendimiento de corredores veteranos en largas distancias. Para ello se elaboró un cuestionario ad hoc. El análisis de los años de experiencia muestra correlaciones significativas (p<0,05) en todas las distancias de la categoría de 35-39 años, así como en la distancia de 21,1 km en categoría 40-44 años. Por otro lado, en la comparación entre categorías relacionados con el tiempo total, se encontraron diferencias significativas en la distancia de 21,1 km para los grupos de edad de 35-39/45-49 (p=0,014) y 35-39/50-54 (p=0,014) así como en la distancia de 42,2 km para los grupos de edad de 35-39/45-49 (p=0,022) y 45- 49/50-54 (p=0,050). Los años de experiencia parecen ser un factor limitante del rendimientoIn the last decades, the number of recreational master runners in long-distance running events has increased. This study, which included 103 runners, aimed to analyze the influence of age and training experience on master runners' performance over long distances. An ad hoc questionnaire was used. Training experience analysis showed significant correlations (p<0.05) in all distances in the 35-39 years category, as well as in the distance of 21.1 km in the 40-44 years category. Furthermore, in the comparison between categories related to the total time, significant differences were found in 21.1 km distance for age groups of 35-39 / 45-49 (p=0.014) and 35-39 / 50-54 (p= 0.014) as well as in 42.2 km distance for the age groups of 35-39 / 45-49 (p=0.022) and 45-49 / 50- 54 (p=0.050). Training experience appears to be a limiting factor for performance in recreational master runner

World-class long- distance running performances are best predicted by volume of easy runs and deliberate practice of short interval and tempo runs

The aim of this novel study was to analyze the effect of deliberate practice (DP) and easy runs completed by elite-standard and world-class long-distance runners on competitive performances during the first 7 years of their sport careers. Eighty-five male runners reported their best times in different running events and the amounts of different DP activities (tempo runs and short and long interval sessions) and 1 non-DP activity (easy continuous runs) after 3, 5 and 7 years of systematic training. Pearson’s correlations were calculated between performances (calculated using the IAAF scoring tables) and the distances run for the different activities (and overall total). Simple and Multiple Linear Regression Analysis calculated how well these activities predicted performance. Pearson’s correlations showed consistently large effects on performance of total distance (r ≥ 0.75, P < 0.001), easy runs (r ≥ 0.68, P < 0.001), tempo runs (r ≥ 0.50, P < 0.001) and short interval training (r ≥ 0.53, P < 0.001). Long interval training was not strongly correlated (r ≥ 0.22). Total distance accounted for significant variance in performance (R2 ≥ 0.57, P < 0.001). Of the training modes, Hierarchical Regression Analysis showed that easy runs and tempo runs were the activities that accounted for significant variance in performance (P < 0.01). Although DP activities, particularly tempo runs and short interval training, are important for improving performance, coaches should note that the non-DP activity of easy running was crucial in better performances, partly because of its contribution to total distance run

Full-Scale Digesters: Model Predictive Control with Online Kinetic Parameter Identification Strategy

This work presents a nonlinear model predictive control scheme with a novel structure of observers aiming to create a methodology that allows feasible implementations in industrial anaerobic reactors. In this way, a new step-by-step procedure scheme has been proposed and tested by solving two specific drawbacks reported in the literature responsible for the inefficiencies of those systems in real environments. Firstly, the implementation of control structures based on modeling depends on microorganisms’ concentration measurements; the technology that achieves this is not cost-effective nor viable. Secondly, the reaction rates cannot be considered static because, in the extended anaerobic digestion model (EAM2), the large fluctuation of parameters is unavoidable. To face these two drawbacks, the concentration of acidogens and methanogens, and the values of the two reaction rates considered have been estimated by a structure of two observers using data collected by sensors. After 90 days of operation, the error in convergence was lower than 5% for both observers. Four model predictive controller (MPC) configurations are used to test all the previous information trying to maximize the volume of methane and demonstrate a satisfactory operation in a wide range of scenarios. The results demonstrate an increase in efficiency, ranging from 17.4% to 24.4%, using as a reference an open loop configuration. Finally, the operational robustness of the MPC is compared with simulations performed by traditional alternatives used in industry, the proportional-integral derivative (PID) controllers, where some simple operational scenarios to manage for an MPC are longer sufficient to disrupt a normal operation in a PID controller. For this controller, the simulation shows an error close to the 100% of the reference valueUniversidad de Sevilla G9104541

The International Olympic Committee framework on fairness, inclusion and nondiscrimination on the basis of gender identity and sex variations does not protect fairness for female athletes

The International Olympic Committee (IOC) recently published a framework on fairness, inclusion, and nondiscrimination on the basis of gender identity and sex variations. Although we appreciate the IOC's recognition of the role of sports science and medicine in policy development, we disagree with the assertion that the IOC framework is consistent with existing scientific and medical evidence and question its recommendations for implementation. Testosterone exposure during male development results in physical differences between male and female bodies; this process underpins male athletic advantage in muscle mass, strength and power, and endurance and aerobic capacity. The IOC's “no presumption of advantage” principle disregards this reality. Studies show that transgender women (male-born individuals who identify as women) with suppressed testosterone retain muscle mass, strength, and other physical advantages compared to females; male performance advantage cannot be eliminated with testosterone suppression. The IOC's concept of “meaningful competition” is flawed because fairness of category does not hinge on closely matched performances. The female category ensures fair competition for female athletes by excluding male advantages. Case-by-case testing for transgender women may lead to stigmatization and cannot be robustly managed in practice. We argue that eligibility criteria for female competition must consider male development rather than relying on current testosterone levels. Female athletes should be recognized as the key stakeholders in the consultation and decision-making processes. We urge the IOC to reevaluate the recommendations of their Framework to include a comprehensive understanding of the biological advantages of male development to ensure fairness and safety in female sports

Emergent Orthotopic Liver Transplantation for Hemorrhage from a Giant Cavernous Hepatic Hemangioma: Case Report and Review

IntroductionCavernous hemangiomas represent the most common benign primary hepatic neoplasm, often being incidentally detected. Although the majority of hepatic hemangiomas remain asymptomatic, symptomatic hepatic hemangiomas can present with abdominal pain, hemorrhage, biliary compression, or a consumptive coagulopathy. The optimal surgical management of symptomatic hepatic hemangiomas remains controversial, with resection, enucleation, and both deceased donor and living donor liver transplantation having been reported.Case reportWe report the case of a patient found to have a unique syndrome of multiorgan cavernous hemangiomatosis involving the liver, lung, omentum, and spleen without cutaneous involvement. Sixteen years following her initial diagnosis, the patient suffered from intra-abdominal hemorrhage due to her giant cavernous hepatic hemangioma. Evidence of continued bleeding, in the setting of Kasabach-Merritt Syndrome and worsening abdominal compartment syndrome, prompted MELD exemption listing. The patient subsequently underwent emergent liver transplantation without complication.ConclusionAlthough cavernous hemangiomas represent the most common benign primary hepatic neoplasm, hepatic hemangioma rupture remains a rare presentation in these patients. Management at a center with expertise in liver transplantation is warranted for those patients presenting with worsening DIC or hemorrhage, given the potential for rapid clinical decompensation

Commentaries on viewpoint : physiology and fast marathons

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