Explore the vast range of titles available.

\"A photo-illustrated book for elementary readers about Olympic speedskating. Includes descriptions of each of the men's and women's long and short races. Readers will get a primer to some rules and athletes that may participate in the 2018 PeyongChang, South Korea Winter Olympic Games. Includes Q&A feature, table of contents, glossary, further resources, and index\"-- Provided by publisher.

Introduction: inline speed skating remains underexplored in scientific literature, especially on curved sections of the track. Objective: given its biomechanical similarities to ice speed skating, this systematic review aims to synthesize current research on biomechanic variables, motor patterns, and observational methodologies. Methodology: following PRISMA guidelines, a systematic search was conducted in Web of Science and PubMed using comprehensive Boolean expressions targeting skating performance and biomechanics. Results: a total of 5825 articles were initially identified, with 4581 unique records screened. Nine studies met the inclusion criteria, focusing on inline or ice speed skating technique during curves. Discussion: the studies analyzed push-off mechanics, leg asymmetry, body tilt, stroke frequency, and trajectory. Video capture methodologies were consistently employed, often synchronized with electromyographic and force measurement tools. Asymmetric push-off behavior, particularly greater contribution from the left leg during the curve, was a key finding. Trajectory optimization and inward tilt were also correlated with enhanced performance. Conclusions: the review highlights that biomechanical asymmetries, especially during crossover techniques, play a critical role in speed maintenance through curves. Consistent trunk-pelvis alignment and skating close to the inner curve line were associated with better outcomes. Future research should prioritize inline skating studies, standardize testing protocols, and expand sample sizes to better inform sport-specific training practices. Introducción: el patinaje de velocidad en línea sigue siendo poco explorado en la literatura científica, especialmente en las secciones curvas de la pista. Objetivo: dadas sus similitudes biomecánicas con el patinaje de velocidad sobre hielo, esta revisión sistemática tiene como objetivo sintetizar la información actual sobre variables biomecánicas, patrones motores y metodologías de observación. Metodología: siguiendo las directrices PRISMA, se realizó una búsqueda sistemática en Web of Science y PubMed utilizando expresiones booleanas exhaustivas orientadas al rendimiento en el patinaje y la biomecánica. Resultados: se identificaron inicialmente 5825 artículos, de los cuales se examinaron 4581 registros únicos. Nueve estudios cumplieron con los criterios de inclusión, centrados en la técnica del patinaje de velocidad en línea o sobre hielo durante curvas. Discusión: los estudios analizaron la mecánica de impulso, la asimetría de las piernas, la inclinación corporal, la frecuencia de zancada y la trayectoria. Las metodologías de captura de vídeo se emplearon de forma constante, a menudo sincronizadas con herramientas de electromiografía y medición de fuerza. Un hallazgo clave fue el comportamiento asimétrico del impulso, en particular una mayor contribución de la pierna izquierda durante la curva. La optimización de la trayectoria y la inclinación hacia el interior también se correlacionaron con un mejor rendimiento. Conclusiones: la revisión destaca que las asimetrías biomecánicas, especialmente durante las técnicas de cruce, desempeñan un papel crítico en el mantenimiento de la velocidad en curvas. La alineación constante del tronco y la pelvis, así como el patinaje cercano a la línea interna de la curva, se asociaron con mejores resultados. Las investigaciones futuras deberían priorizar los estudios sobre patinaje en línea, estandarizar los protocolos de prueba y ampliar el tamaño de las muestras para mejorar las prácticas de entrenamiento específicas del deporte. Introdução: A patinagem de velocidade em linha permanece pouco explorada na literatura científica, particularmente nas secções curvas da pista. Objectivo: Dadas as suas semelhanças biomecânicas com a patinagem de velocidade no gelo, esta revisão sistemática visa sintetizar a informação actual sobre variáveis ​​biomecânicas, padrões de movimento e metodologias de observação. Metodologia: Seguindo as diretrizes PRISMA, foi realizada uma pesquisa sistemática no Web of Science e PubMed utilizando expressões booleanas abrangentes, com foco no desempenho na patinagem e na biomecânica. Resultados: Inicialmente, foram identificados 5825 artigos, dos quais foram examinados 4581 registos únicos. Nove estudos cumpriram os critérios de inclusão, com foco na técnica de patinagem de velocidade em linha ou no gelo durante as curvas. Discussão: Os estudos analisaram a mecânica da propulsão, a assimetria das pernas, a inclinação do corpo, a frequência da passada e a trajetória. As metodologias de captura de vídeo foram empregues de forma consistente, frequentemente sincronizadas com a eletromiografia e as ferramentas de medição de força. Uma descoberta fundamental foi o comportamento assimétrico da propulsão, particularmente uma maior contribuição da perna esquerda durante a curva. A otimização da trajetória e a inclinação para dentro também foram correlacionadas com um melhor desempenho. Conclusões: Esta revisão realça que as assimetrias biomecânicas, especialmente durante as técnicas de cruzamento, desempenham um papel crucial na manutenção da velocidade em curva. O alinhamento consistente do tronco e da bacia, bem como a patinagem junto à linha interna da curva, estiveram associados a melhores resultados. Pesquisas futuras devem priorizar estudos sobre patinagem em linha, padronizar os protocolos de teste e aumentar o tamanho das amostras para melhorar as práticas de treino específicas para o desporto.

This paper studies the tactical decision-making model of short track speed skating based on deep reinforcement learning, so as to improve the competitive performance of corresponding short track speed skaters. Short track speed skating, a traditional discipline in the Winter Olympics since its establishment in 1988, has consistently garnered attention. As artificial intelligence continues to advance, the utilization of deep learning methods to enhance athletes’ tactical decision-making capabilities has become increasingly prevalent. Traditional tactical decision techniques often rely on the experience and knowledge of coaches and video analysis methods that require a lot of time and effort. Consequently, this study proposes a scientific simulation environment for short track speed skating, that accurately simulates the physical attributes of the venue, the physiological fitness of the athletes, and the rules of the competition. The Double Deep Q-Network (DDQN) model is enhanced and utilized, with improvements to the reward function and the distinct description of four tactics. This enables agents to learn optimal tactical decisions in various competitive states with a simulation environment. Experimental results demonstrate that this approach effectively enhances the competition performance and physiological fitness allocation of short track speed skaters.

Inertial measurement units (IMUs) have been used increasingly to characterize long-track speed skating. We aimed to estimate the accuracy of IMUs for use in phase identification of long-track speed skating. Twelve healthy competitive athletes on a university long-track speed skating team participated in this study. Foot pressure, acceleration and knee joint angle were recorded during a 1000-m speed skating trial using the foot pressure system and IMUs. The foot contact and foot-off timing were identified using three methods (kinetic, acceleration and integrated detection) and the stance time was also calculated. Kinetic detection was used as the gold standard measure. Repeated analysis of variance, intra-class coefficients (ICCs) and Bland-Altman plots were used to estimate the extent of agreement between the detection methods. The stance time computed using the acceleration and integrated detection methods did not differ by more than 3.6% from the gold standard measure. The ICCs ranged between 0.657 and 0.927 for the acceleration detection method and 0.700 and 0.948 for the integrated detection method. The limits of agreement were between 90.1% and 96.1% for the average stance time. Phase identification using acceleration and integrated detection methods is valid for evaluating the kinematic characteristics during long-track speed skating.

Long‐haul travel poses significant challenges to sleep in elite athletes, yet evidence‐based interventions tested in competitive settings remain scarce. This study investigated the effects of timing‐based interventions on sleep in 10 national‐level Canadian speed skaters prior to a World Cup competition in Beijing (13 time zones crossed). Athletes followed a tailored sleep schedule upon arrival and for the days preceding the competition. Total sleep time in Beijing was not different from Canada (p = 0.254) or pre‐season (p = 0.999) and was lower the night before travel (p < 0.001) due to the early flight to Beijing. When comparing data with a similar dataset presenting no intervention, bedtime was successfully delayed and resulted in later wake‐up time and longer total sleep time. Total sleep time increased by ~10 min/night, suggesting adjustments in sleep–wake rhythm during the first days upon arrival were still present. Race performance was unaffected by travel, with no time effect on overall rank (p = 0.74). These preliminary findings suggest that individualized timing‐based strategies might support sleep regulation and circadian re‐synchronization in elite athletes following long‐haul travel. Further studies are warranted to confirm these results in larger samples and explore the effectiveness of customized timing‐based intervention on different time changes and on performance. Timing‐based strategies for sleep and training scheduling are a promising intervention to increase the total amount of sleep obtained when traveling for competitions.

This study aimed to determine the effects of technique asymmetry on 500 m straight-track speed skating performance. We analyzed 20 elite skaters, measuring their joint angles, center of mass shift, and times and speeds during the gliding and push-off phases. The technique asymmetry index (ASI) was calculated for each parameter, and paired t-tests were used to compare bilateral asymmetry. Spearman correlation coefficients assessed the relationship between the ASI and both the average straight track speed and overall performance. Significant bilateral asymmetries in the knee, push-off, trunk, and hip angles were found in both male and female participants (p < 0.05). The male participants demonstrated a higher right push-off speed (p = 0.029) and a longer left gliding time (p = 0.048). Significant asymmetry was also observed in the lateral shift of the center of mass during each phase of the straight-track skating gait cycle (p < 0.001). No significant correlation was found between the ASIs and the overall performance (p ≥ 0.067). These findings indicate that while elite speed skaters demonstrated significant bilateral technique asymmetry in straight track skating, these asymmetries did not significantly impact their overall performance.

In this paper, 64 national first-class athletes in speed skating and short-track speed skating were selected to participate in hypoxia training. In the study, athletes participated in a total of eight weeks of training, measured and analyzed the physiological indexes of athletes in normoxic environment and hypoxic environment. In the study, data analysis combined with machine learning was used to obtain the conversion formula of athletes' physiological indexes in hypoxia training and normoxia training. The experimental results show that the simulated hypoxia environment of 2300m is effective for athletes participating in both sports, in which the effect of short track speed skating is obvious, and the effect of speed skating is weak. Through the analysis, it is found that female athletes are more easily affected by hypoxia training. Relatively speaking, women who take part in the same hypoxia training get more benefits. The physiological indexes in normoxic environment and hypoxic environment are used in machine learning, and the transformation formulas of various physiological indexes under the environmental conditions in this study are successfully obtained. It is proved that the error between the hypoxia physiological index estimated by the transformation formula and the actual physiological index is small, which shows that the transformation formula is more accurate. This proves that hypoxia training can be estimated by means of machine learning to obtain more accurate data guidance, which has a strong practical significance for coaches to guide athletes' training.

Introduction The aim of this study was to combine proteomics and metabolomics to evaluate the immune system of short‐track speed skaters (STSS) before and after a training course. Our research focused on changes in urinary proteins and metabolites that have the potential to serve as indicators for training load. Methods Urine samples were collected from 21 elite STSS (13 male and 8 female) of the China National Team before and immediately after one training course. First‐beat sports sensor was used to monitor the training load. Proteomic detection was performed using a Thermo UltiMate 3000 ultra high performence chromatography nano liquid chromatograph and an Orbitrap Exploris 480 mass spectrometer. MSstats (R package) was used for the statistical evaluation of significant differences in proteins from the samples. Two filtration criteria (fold change [FC] > 2 and p < 0.05) were used to identify the differential expressed proteins. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis for differential proteins was performed to identify the pathways involved. Nontargeted metabolomic detection was performed using ultra performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS_) with an ACQUITY 2D UPLC plus Q Exactive (QE) hybrid Quadrupole‐Orbitrap mass spectrometer. Differential metabolites were identified using non‐parametric statistical methods (Wilcox's rank test). Two filtration criteria (FC > 1.2 and p < 0.05) were used to identify differential metabolites. Combined analysis of proteomic and metabolomics were performed on the “Wu Kong” platform. Correlation analysis was performed using Spearman's rank correlation coefficient. Results (1) The most upregulated proteins were immune‐related proteins, including complement proteins (C9, C4–B, and C9) and immunoglobulins (IgA, IgM, and IgG). The most downregulated proteins were osteopontin (OPN) and CD44 in urine. The correlation analysis showed that the content of OPN and CD44 (the receptor for OPN) in urine were significantly negatively correlated with the upregulated immune‐related proteins. The content of OPN and CD44 is sex‐dependent and negatively correlated with the training load. (2) The most upregulated metabolites included lactate, cortisol, inosine, glutamine, argininosuccinate (the precursor for arginine synthesis), 3‐methyl‐2‐oxobutyrate (the catabolite of valine), 3‐methyl‐2‐oxovalerate (the catabolite of isoleucine), and 4‐methyl‐2‐oxopentanoate (the catabolite of leucine), which is sex‐dependent and negatively correlated with OPN and CD44. (3) The joint analysis revealed five main related pathways, including the immune and innate immune systems. The enriched immune‐related proteins included complements, immunoglobulins, and protein catabolism‐related proteins. The enriched immune‐related metabolites included cAMP, N‐acetylgalactosamine, and glutamate. (4) There is a significant negative correlation between the content of OPN and CD44 in urine and the training load. Conclusion One training course can lead to the activation of the immune system and a sex‐dependent decrease in the content of OPN and CD44. Training load has a significant and negative correlation with the content of OPN and CD44, suggesting that OPN and CD44 could be potential indicators for training load. One training course stimulates the immune response, and this reaction can be significantly reflected in urine. Moreover, the osteopontin (OPN)/CD44 pathway may be a potential indicator for training load in elite short track speed skaters.

The physiological and biomechanical characteristics of inline speed skating have not been systematically mapped nor research evidence synthesized. The aim was to identify and synthesize novel elements across studies, including participant characteristics, outcomes measures, experimental protocol, main outcomes and other relevant information, to inform evidence-based guidelines and recommendations. Following the PRISMA 2020 guidelines, a systematic search of databases was conducted to identify relevant studies. The extracted data were charted and synthesized to summarize the physiological and biomechanical aspects of inline speed skating. From 272 records, 22 studies met the defined criteria. Studies related to inline speed skating focused primarily on physiological variables (n = 14) and lower limb muscles function, with limited evidence on biomechanics of inline speed skating (n = 5) and the combination of biomechanics and physiology (n = 3). An overall unclear risk of bias was observed (59% of studies). Although studies have examined physiological and biomechanical variables, continuous physiological and biomechanical assessments of skaters performing different skills on both straight and curved tracks have not been conducted. Therefore, well-planned physiological and biomechanics studies are required to uncover underexplored areas in research and support the development of sport-specific studies.