Muscle synergies are shared across fundamental subtasks in complex movements of skateboarding.

A common theory of motor control posits that movement is controlled by muscle synergies. However, the behavior of these synergies during highly complex movements remains largely unexplored. Skateboarding is a hardly researched sport that requires rapid motor control to perform tricks. The objectives of this study were to investigate three key areas: (i) whether motor complexity differs between skateboard tricks, (ii) the inter-participant variability in synergies, and (iii) whether synergies are shared between different tricks. Electromyography data from eight muscles per leg were collected from seven experienced skateboarders performing three different tricks (Ollie, Kickflip, 360°-flip). Synergies were extracted using non-negative matrix factorization. The number of synergies (NoS) was determined using two criteria based on the total variance accounted for (tVAF > 90% and adding an additional synergy does not increase tVAF > 1%). In summary: (i) NoS and tVAF did not significantly differ between tricks, indicating similar motor complexity. (ii) High inter-participant variability exists across participants, potentially caused by the low number of constraints given to perform the tricks. (iii) Shared synergies were observed in every comparison of two tricks. Furthermore, each participant exhibited at least one synergy vector, which corresponds to the fundamental 'jumping' task, that was shared through all three tricks.

Relevant Biomechanical Variables in Skateboarding: A Literature Review.

Skateboarding, once regarded primarily as a means of transportation and entertainment for youth, has become a recognized professional sport, gaining global popularity. With its recent inclusion in the Olympics, a growing imperative exists to comprehensively understand biomechanics explaining skateboarding performance. This literature review seeks to consolidate knowledge within this domain, focusing on experimental and modeling studies about skateboard riding and tricks. The criteria for study selection encompassed content relevance and publication year, spanning from the last two decades and extending further back to 1980 following cross-referencing of seminal works. Peer-reviewed journal articles, conference proceedings, and books were considered, with comprehensive searches conducted on electronic databases, including SCOPUS, PubMed, Scielo, and Taylor & Francis. Comprehending the biomechanical facets of skateboarding is essential in promoting its use and ensuring safety among all practitioners. Insights into factors such as body kinetics, kinematics, and muscle activation represent a foundational step toward understanding the nuances of this sport with implications for both clinical and biomechanical research. Modern data collection systems such as inertial measurement units (IMU) and electromyography (EMG) offer unprecedented insights into human performance during skateboarding, such as joint range of motion, coordination, and muscle activation, whether in casual riding or executing complex tricks and maneuvers. Developing robust modeling approaches also holds promise for enhancing skateboarding training and performance. Crucially, these models can serve as the initial framework for understanding injury mechanisms and implementing strategies to improve performance and mitigate injury risks.

Epidemiology, etiology and prevention of injuries in competitive ice speed skating-limited current evidence, multiple future priorities: A scoping review.

Long-track and short-track ice speed skating are integral to the Winter Olympics. The state of evidence-based injury prevention in these sports is unclear. Our goals were to summarize the current scientific knowledge, to determine the state of research, and to highlight future research areas for injury prevention in ice speed skating. We conducted a scoping review, searching all injury and injury prevention studies in competitive ice speed skaters. The six-stage Translating Research into Injury Prevention Practice (TRIPP) framework summarized the findings. The systematic search yielded 1109 citations. Nineteen studies were included, and additional searches yielded another 13 studies, but few had high-quality design. TRIPP stage 1 studies (n = 24) found competition injury rates from 2% to 18% of participants with various injury locations and types. Seasonal prevalence of physical complaints was up to 84% (for back pain) in long- and short-track. Ten studies covered information on TRIPP stage 2, with two small etiological studies linking injuries to functional strength deficits (short-track) and training load (long-track). Questionnaire studies identified various perceived risk factors for injuries but lacked further scientific evidence. Most TRIPP stage 3 studies (five out of eight) focused on developing protective measures, while two studies found short-track helmets performed poorly compared to helmets used in other sports. No study evaluated the efficacy, the intervention context, or the effectiveness (TRIPP stages 4-6) of the measures. Scientific knowledge on injury prevention in ice speed skating is limited. Future research should prioritize high-quality studies on injury epidemiology and etiology in the sports.

The Impact of an 8-Week Resisted Sprint Training Program on Ice Skating Performance in Male Youth Ice Hockey Players.

ABSTRACT: Dietze-Hermosa, MS, Montalvo, S, Gonzalez, MP, and Dorgo, S. The impact of an 8-week, resisted, sprint training program on ice skating performance in male youth ice hockey players. J Strength Cond Res 38(5): 957-965, 2024-The purposes of this randomized control study were to (a) compare the effects of an on-ice versus an overground resisted sprint training intervention and a control condition and (b) identify changes in ice skating kinematics and kinetics after training intervention participation. Twenty-four youth ice hockey players were randomly allocated into 3 groups: (a) on-ice resisted sprint training (on-ice RST); (b) overground resisted sprint training (overground RST); and (c) body weight resistance training (control). During the 8-week intervention, the 2 RST groups engaged in sled towing methods, whereas the control group engaged in a body weight resistance training program twice a week. A series of individual, repeated-measures analysis of variances with post hoc pairwise comparisons were conducted for variables of interest. An interaction effect was noted for ice skating s-cornering agility drill completion time ( p = 0.01; ηp2 = 0.36), ice skating 30-m top speed completion time ( p = 0.04; ηp2 = 0.27), step length ( p = 0.04; ηp2 = 0.26), and knee angle at touchdown ( p = 0.03; ηp2 = 0.30). The on-ice RST group displayed superior improvements across ice skating tests compared with the control group. Data show that on-ice RST has the greatest transfer effect to ice skating metrics; however, improvements in certain ice skating metrics can be observed with overground training also.

Physical fitness and motor ability parameters as predictors for skateboarding performance: A logistic regression modelling analysis.

The identification and prediction of athletic talent are pivotal in the development of successful sporting careers. Traditional subjective assessment methods have proven unreliable due to their inherent subjectivity, prompting the rise of data-driven techniques favoured for their objectivity. This evolution in statistical analysis facilitates the extraction of pertinent athlete information, enabling the recognition of their potential for excellence in their respective sporting careers. In the current study, we applied a logistic regression-based machine learning pipeline (LR) to identify potential skateboarding athletes from a combination of fitness and motor skills performance variables. Forty-five skateboarders recruited from a variety of skateboarding parks were evaluated on various skateboarding tricks while their fitness and motor skills abilities that consist of stork stance test, dynamic balance, sit ups, plank test, standing broad jump, as well as vertical jump, were evaluated. The performances of the skateboarders were clustered and the LR model was developed to classify the classes of the skateboarders. The cluster analysis identified two groups of skateboarders: high and low potential skateboarders. The LR model achieved 90% of mean accuracy specifying excellent prediction of the skateboarder classes. Further sensitivity analysis revealed that static and dynamic balance, lower body strength, and endurance were the most important factors that contributed to the model's performance. These factors are therefore essential for successful performance in skateboarding. The application of machine learning in talent prediction can greatly assist coaches and other relevant stakeholders in making informed decisions regarding athlete performance.

Maximum Strength and Power as Determinants of Match Skating Performance in Elite Youth Ice Hockey Players.

ABSTRACT: Keiner, M, Kierot, M, Stendahl, M, Brauner, T, and Suchomel, TJ. Maximum strength and power as determinants of match skating performance in elite youth ice hockey players. J Strength Cond Res 38(6): 1090-1094, 2024-Maximum strength has a strong influence on speed-strength performances such as sprints and jumps. Important for sports practice is whether these findings are also reflected in game performance. Therefore, the aim of this study was to explore the influence of maximum strength and power performance on linear on-ice skating performance in testing and during game play. A cross-sectional study was conducted, and 24 highly trained male youth ice hockey players participated. Jump performances (countermovement jump [CMJ], drop jumps), maximum strength (1 repetition maximum [1RM] squat and isometric trap bar pull [ITBP]), and on-ice linear sprints (15 m [LS15], 30 m [LS30], flying 15 m [FLY15]) were measured. Match performances (among others: peak skating speed) were collected of 4 regular league games using a local positioning system. Correlation coefficient and explained variance were calculated ( ρ ≤ 0.05). Correlations between maximum strength and jump with on-ice linear sprint performance showed 1-35% explained variance. Correlations between "off ice" test (CMJ, relative 1RM) and game data (peak skating speed) showed 22-30% explained variance, respectively, while ITBP and DJ missed significant level. Between linear sprint and game performance showed 15-59% explained variance. In this study, a clear influence of 1RM in squatting and CMJ performance on on-ice linear sprint as well as in-game peak skating speed was observed. These findings show that strength and jumping performance can be valuable tests within a comprehensive test battery and indicate the relevance of strength and jumping tasks within the regular exercise program to improve in-game skating performance.

Injury characteristics of young elite inline speed skaters: A one season retrospective study.

OBJECTIVES: Determining the rate of injuries related to a certain sport is accepted as the primary step toward designing, implementing and evaluating injury prevention programs. This observational and retrospective study was to examine the injuries sustained by elite young Spanish inline speed skaters during a season. METHODS: Athletes participating in the national championship (n = 80) were surveyed via an anonymous online questionnaire to screen for injury characteristics: incidence, location, and tissue affected; plus training information and demographics. RESULTS: A total of 52 injuries were recorded across 33,351 hours of exposure, which gives a rate of 1.65/1,000 h. The lower body comprised 79% of the total amount of injuries (1.3/1000 h), and the main areas affected were the thigh and foot, accounting for 25% and 19.2% of the recorded injuries, respectively. Musculotendinous injuries were the most frequent, with an incidence of 0.92/1000 h. No significant gender differences were observed for any of the variables studied. CONCLUSION: Speed skating can be considered a low injury rate sport based on our findings. The risk of sustaining an injury was independent of gender, age, and BMI.

Modeling the Early and Late Acceleration Phases of the Sprint Start in Elite Long Track Speed Skaters.

ABSTRACT: Zukowski, MH, Jordan, MJ, and Herzog, W. Modeling the early and late cceleration phases of the sprint start in elite long track speed skaters. J Strength Cond Res 38(2): 236-244, 2024-This study established the reliability of an exponential function to model the change in velocity during the speed skating sprint start and the validity of associated model parameters in a group of subelite and elite long track speed skaters. Long track speed skaters ( n = 38) performed maximal effort 50-m on-ice accelerations from a standing start while tethered to a horizontal robotic resistance device that sampled position and time data continuously. An exponential function was applied to the raw data to model the change in velocity throughout the acceleration phase and compute the maximal skating speed (MSS), maximal acceleration capacity (MAC), maximum relative net horizontal power ( PMax ), and an acceleration-time constant ( τ ). All constructed models provided a sufficient fit of the raw data ( R -squared > 0.95, mean bias <2%). Intraday reliability of all model parameters ranged from good to excellent (intraclass correlation coefficient >0.8 and coefficient of variation <5%). Strong negative correlations ( r : -0.72 to -0.96) were observed between MSS and PMax and the 10 and 20 m split times measured with the robotic resistance and with 100 split times obtained from 500 m races. Moderate-to-large between-group differences were observed in MSS, MAC, and PMax between the elite vs. subelite speed skaters (Cohen d effect sizes: 1.18-3.53). Our results indicate that monoexponential modeling is a valid and reliable method of monitoring initial acceleration performance in elite level long track speed skaters.

Performance-Determining Variables of a Simulated Sprint Cross-Country Skiing Competition.

PURPOSE: To investigate performance-determining variables of an on-snow sprint cross-country skiing competition and the evolvement in their relationship with performance as the competition progresses from the individual time trial (TT) to the final. METHODS: Sixteen national-level male junior skiers (mean [SD] age, 18.6 [0.8] y; peak oxygen uptake [VO2peak], 67.6 [5.5] mL·min-1·kg-1) performed a simulated sprint competition (1.3 km) in the skating style, comprising a TT followed by 3 finals (quarterfinals, semifinals, and final) completed by all skiers. In addition, submaximal and incremental roller-ski treadmill tests, on-snow maximal speed tests, and strength/power tests were performed. RESULTS: VO2peak and peak treadmill speed during incremental testing and relative heart rate, rating of perceived exertion, blood lactate concentrations, and gross efficiency during submaximal testing were all significantly correlated with performance in the TT and subsequent finals (mean [range] r values: .67 [.53-.86], all P < .05). Relative VO2peak and submaximal relative heart rate and blood lactate concentration were more strongly correlated with performance in the semifinals and final compared with the TT (r values: .74 [.60-.83] vs 0.55 [.51-.60], all P < .05). Maximal speed in uphill and flat terrain was significantly correlated with performance in the TT and subsequent finals (r values: .63 [.38-.70], all P < .05), while strength/power tests did not correlate significantly with sprint performance. CONCLUSIONS: VO2peak and high-speed abilities were the most important determinants of sprint cross-country skiing performance, with an increased importance of VO2peak as the competition format progressed toward the final.

Comprehensive analysis of performance, physiological, and perceptual responses during an entire sprint cross-country skiing competition.

PURPOSE: To investigate performance, physiological, and perceptual responses of an entire sprint cross-country skiing competition in the skating style. METHODS: Eighteen national-level male junior skiers participated in a simulated competition comprising an individual time trial (TT), followed by three heats (quarterfinals [QF], semifinals [SF], and final [F]). Participants' heart rate (HR) was continuously monitored while perceived readiness (RED, 1-10), rating of perceived exertion (RPE, 6-20), and blood lactate [La-] were assessed at standardized time points. RESULTS: The total duration and distance covered were 03:30 ± 00:06 h and 25.2 ± 2.9 km, respectively. The participants spent 02:19 ± 00:27 h > 60% of their maximal HR (HRmax) and 00:16 ± 00:04 h > 85% of HRmax. Average HR decreased from TT to F (89.3 ± 2.0% vs. 86.9 ± 3.0% of HRmax, P < 0.01). [La-] levels were highest before (4.6 ± 2.0 vs. 2.9 ± 1.2, 3.2 ± 2.0 and 2.5 ± 1.3 mmol·L-1, all P < 0.01) and after (10.8 ± 1.4 vs. 9.8 ± 1.6, 9.1 ± 1.8 and 8.7 ± 1.7 mmol·L-1, all P < 0.05) F compared to TT, QF, and SF, respectively. RED was lowest before F compared to TT, QF, and SF (6.6 ± 1.4 vs. 7.9 ± 1.1, 7.6 ± 1.1, and 7.4 ± 1.4, respectively, all P < 0.05) while RPE was highest after TT compared to QF, SF, and F (17.8 ± 0.9 vs. 15.1 ± 2.0, 16.5 ± 1.2 and 16.6 ± 1.8, respectively, all P < 0.01). The six best-performing skiers demonstrated higher RED before F (7.2 ± 0.9 vs. 5.3 ± 1.2, P < 0.05) and higher [La-] after F (11.2 ± 0.2 vs. 10.2 ± 0.3, mmol·L-1, P < 0.05) than lower-performing competitors. CONCLUSION: This study provides novel insights into physiological demands of an entire sprint cross-country skiing competition, which involves repeated 3-min high-intensity efforts interspersed with > 2 h (25 km) of low- to moderate-intensity exercise.

Peer and parent influences on youth skateboarding and factors that affect their decision to return to the sport after injury.

Skateboarding is an increasingly popular sport among youth, despite the fact that they are a high-risk group for injuries during this activity. The purpose of this study was twofold: to explore youths' perceptions about the influences that peers and parents have on their skateboarding; and to identify factors that affect their decisions about returning to the sport after injury. Virtual semi-structured interviews were conducted with 26 youth, 14-17 years of age, who had experienced a medically-treated injury while skateboarding during the past year. Applying thematic analyses, major findings indicated that sharing the activity with peers fosters psychological well-being, companionship, and a valued sense of community that motivates return to the sport even after serious injury and sometimes before they are fully physically ready to do so safely. Parental concerns about physical injury (vulnerability, severity) were acknowledged but not influential, with youth feeling that parents do not appreciate the valued mental health benefits that they experience from the skateboarding community. Youth reported withholding injury information from parents, hiding injuries and downplaying their severity, and not always disclosing returning to the sport. Youths' decisions to return to the sport after injury was motivated by their feelings that skateboarding enhances their sense of identity, promotes their mental health, and provides respite because it allows them to escape from reality temporarily. Recommendations for reducing risk of injury to youth skateboarders at skateparks are provided.

Estimated prevalence of helmet use while bicycling, rollerblading, and skateboarding among middle school students in selected U.S. States- Youth Behavior Risk Survey, 2013-2019.

BACKGROUND: Helmet use helps prevent severe and fatal head and brain injuries from bicycle, rollerblade, and skateboard crashes. This study explores the prevalence of self-reported helmet use among middle school students while bicycling, skateboarding, and rollerblading. METHODS: Data from the Middle School Youth Risk Behavior Survey (YRBS) for selected states were analyzed. Self-reported prevalence (frequency) of helmet use while bicycling, rollerblading, or skateboarding and other variables (sex, grade level, and race/ethnicity) are reported. RESULTS: The overall prevalence of rarely or never wearing a helmet while bicycling among middle school students in selected states was 68.6%; decreasing from 71.7% in 2013 to 67.1% in 2019. The overall prevalence of rarely or never wearing a helmet while rollerblading or skateboarding in middle school students in selected states was 74.6%; decreasing from 76.4% in 2013 to 73.5% in 2019. Students in 7th and 8th grade and students of non-Hispanic race/ethnicity had significantly higher odds of rarely or never wearing a helmet while bicycling or while rollerblading and skateboarding than students in 6th grade and non-Hispanic White students. CONCLUSIONS: While helmet use among middle school students improved over time, overall helmet use during bicycling, rollerblading, and skateboarding remained low. These estimates illustrate the continued call for universal implementation of helmet use efforts among kids using established strategies. PRACTICAL APPLICATIONS: Future research on helmet use among youth who rollerblade and skateboard, as well as multi-pronged efforts to promote helmet use among middle schoolers who bicycle, skateboard, and rollerblade (inclusive of education, helmet distribution, and social marketing techniques, as well as the provision of helmets at no-cost) may be beneficial for addressing perceived risks for injury and other barriers.

Enhancing Short Track Speed Skating Performance through Improved DDQN Tactical Decision Model.

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.

Action Quality Assessment Model Using Specialists' Gaze Location and Kinematics Data-Focusing on Evaluating Figure Skating Jumps.

Action quality assessment (AQA) tasks in computer vision evaluate action quality in videos, and they can be applied to sports for performance evaluation. A typical example of AQA is predicting the final score from a video that captures an entire figure skating program. However, no previous studies have predicted individual jump scores, which are of great interest to competitors because of the high weight of competition. Despite the presence of unnecessary information in figure skating videos, human specialists can focus and reduce information when they evaluate jumps. In this study, we clarified the eye movements of figure skating judges and skaters while evaluating jumps and proposed a prediction model for jump performance that utilized specialists' gaze location to reduce information. Kinematic features obtained from the tracking system were input into the model in addition to videos to improve accuracy. The results showed that skaters focused more on the face, whereas judges focused on the lower extremities. These gaze locations were applied to the model, which demonstrated the highest accuracy when utilizing both specialists' gaze locations. The model outperformed human predictions and the baseline model (RMSE:0.775), suggesting a combination of human specialist knowledge and machine capabilities could yield higher accuracy.

Nutrition Status of Female Winter Sports Athletes.

Eating disorders, especially restrictive eating, are common among female athletes. There are two main types of winter sports: those that are practiced outdoors on snow (-25 to +5 °C and 2500 m), such as alpine skiing and snowboarding, and those that are practiced indoors on ice (5-10 °C at low altitude), such as figure skating and ice hockey. The aim of this research was to identify the nutritional status and potential risk of female athletes practicing winter sports, considering the altitude of training. The sample was composed of 58 women (aged 19.81 years (SD: 12.61)) who were competitors in some winter sports. Anthropometrics and nutritional variables were taken. Statistically significant differences were found between HA and LA groups for all the characteristics except thigh skinfold, and neither group had an energy intake (EI) that matched their total energy expenditure (TEE). Both groups met at least two-thirds of the RDI for all minerals and vitamins except iodine, fluorine, vitamin D, vitamin E, and retinol. This study suggests that female winter sports athletes have insufficient energy, vitamin, and mineral intake, which can be worsened with altitude.

The Relationship Between Lower-Body Force-Time Variables and Skating Performance in Female Ice Hockey Players.

PURPOSE: Ice hockey is a team invasion sport characterized by repeated high-intensity skating efforts, technical and tactical skill, physical contact, and collisions requiring considerable levels of muscular strength. The purpose of this study was to evaluate the relationships between lower-body vertical force-time metrics and skating qualities in subelite female ice hockey players. METHODS: A cross-sectional cohort design was employed utilizing 14 athletes (body mass = 66.7 [1.8] kg; height = 171.6 [6.2] cm; age = 21.1 [1.7] y). The relationships between metrics of lower-body strength collected from a drop jump, squat jump, countermovement jump, loaded countermovement jump, and an isometric squat and 4 skating qualities collected from a linear sprint, repeated sprint test, and a multistage aerobic test were evaluated. RESULTS: The regression models revealed a positive relationship between relative peak force in the isometric squat and skating multistage aerobic test performance (r2 = .388; P = .017) and a positive relationship between repeated-sprint ability and eccentric mean force during the loaded countermovement jump (r2 = .595; P = .001). No significant relationships were observed between strength metrics and skating acceleration or maximal velocity. CONCLUSIONS: These data suggest that skating ability is most affected by relative isometric strength in female ice hockey players. It is recommended that practitioners focus training on tasks that improve relative force output. It is also recommended that isometric relative peak force be used as a monitoring metric for this cohort.

Adolescents' Perspectives on Skateboarding and Injury Risk: The Benefits Outweigh the Risks.

OBJECTIVE: Skateboarding is an increasingly popular sport among youth, despite the fact that children and adolescents are the age groups most frequently injured when skateboarding. A greater understanding of the psycho-social factors that motivate participation in skateboarding, including why youth return to the sport after serious injury from skateboarding, is needed to inform injury prevention efforts. This study addressed that gap in knowledge. METHODS: Twenty-six Canadian adolescent skateboarders 14-17 years of age (20 males and 6 females) who had previously sustained medically attended injuries while skateboarding participated in individual interviews to explore their perspectives on skateboarding and injury risk, including reasons for returning to the sport after injury. RESULTS: Thematic analyses revealed that participants perceived many unique benefits from skateboarding, including interpersonal benefits, mental and physical health benefits, pleasure, personal growth, and identity development. Participants uniformly identified that a major drawback was the risk of injury, with trickle-down effects of injury including a loss of social contacts (e.g., missing friends), challenges to individual identity from not participating, and injury-specific negative outcomes (e.g., pain, physical limitations). When exploring reasons participants returned to the sport and to the trick or activity that precipitated their injury, the primary theme identified was that the benefits of skateboarding significantly outweighed the costs associated with potential re-injury. CONCLUSION: Results paint a nuanced picture of psycho-social factors that impact youths' skateboarding and decisions to return to the sport after injury. Implications for injury prevention are discussed.

Femoroacetabular Impingement in Ice Hockey Athletes.

ABSTRACT: Femoroacetabular impingement (FAI) in ice hockey is a concern for many athletes. The biomechanics of skating and the injury mechanism, prevalence, identification, and treatment protocols currently available for FAI in ice hockey athletes are important for all coaches and practitioners to understand. This article discusses the underlying anatomical issues and biomechanical considerations surrounding FAI. Furthermore, this article describes the interventions that can be used when encountering FAI and well-established protocols to aid in the return to play. Finally, prevention strategies that can aid in injury prevention are discussed.

Anaerobic Speed Reserve and Performance Relationships Between International and World-Class Short-Track Speed Skating.

PURPOSE: Short-track speed skating race distances of 500, 1000, and 1500 m that last ∼40 seconds to ∼2.5 minutes and require a maximal intensity at speeds beyond maximal oxygen uptake (VO2max). Recently, the anaerobic speed reserve (ASR) has been applied by scientists and coaches in middle-distance sports to deepen understanding of 1- to 5-minute event performance where different physiological profiles (speed, hybrid, and endurance) can have success. METHODS: World-class (women, n = 2; men, n = 3) and international-level (women, n = 4; men, n = 5) short-track speed skaters completed maximal aerobic speed and maximal skating speed tests. ASR characteristics were compared between profiles and associated with on-ice performance. RESULTS: World-class athletes raced at a lower %ASR in the 1000- (3.1%; large; almost certainly) and 1500-m (1.8%; large; possibly) events than international athletes. Men's and women's speed profiles operated at a higher %ASR in the 500-m than hybrid and endurance profiles, whereas in the 1500-m, endurance profiles worked at a substantially lower %ASR than hybrid and speed profiles. Women's 500-m performance is very largely associated with maximal skating speed, while women's maximal aerobic speed appears to be a key determining factor in the 1000- and 1500-m performance. CONCLUSION: World-class short-track speed skaters can be developed in speed, hybrid, and endurance profiles but achieve their performance differently by leveraging their strongest characteristics. These results show nuanced differences between men's and women's 500-, 1000- and 1500-m event performance across ASR profile that unlock new insights for individualizing athlete performance in these disciplines.

Beware! We are Skating on a Thin Ice: Air Pollution is a Killer.

Air pollution has rapidly emerged as a major environmental hazard in recent times, with potentially catastrophic ramifications for human health.1,2 It has the ability to severely and adversely impact multiple body systems, including the central nervous system (CNS), cardiovascular, dermatological, respiratory, ophthalmologic, and gastrointestinal health. It is a global public health hazard, being responsible for an estimated 6.7 million deaths worldwide in 2016. The World Health Organization (WHO) estimates that between 3.2 to 4.8 million persons succumb yearly because of outdoor and indoor air pollution, respectively. Nearly 90% of people worldwide live in regions where mean air pollution levels exceed acceptable ranges established by WHO.3 Air pollution is caused by several components in the air, which include particulate matter (PM), organic compounds such as polycyclic aromatic hydrocarbons (PAH), inorganic compounds, gases such as nitrogen oxides (NOx), and sulfur dioxide (SO2). PM, in turn, is further classified based on the aerodynamic diameter of the particles: coarse particles are defined as those with a diameter between 2.5 and 10 µm (PM10), fine particles are those with a diameter <2.5 µm but above 100 nm (PM2.5) and ultrafine particles are those with diameter below 100 nm (ultrafine PM). Larger particles (PM10) are more common in industrial emissions, and smaller particles in automobile emissions. Data continues to accumulate on the adverse consequences of air pollution on brain health, with pathogenetic contributions  to the development of dementia, headache, stroke, demyelinating conditions, and psychiatric disorders.