Race Distance Research Articles

Study of the anthropometric indices of muscle mass in different sports modalities of all genders.

Muscle mass is one of the main components of an athlete's body weight. Its development is related to the biomechanical gesture and the strength required to physical activity. The aim of the study was to assess musculoskeletal development by means of anthropometric indices in sports with different demands. The sample comprised 780 subjects (58.2% male), age 23.8 ± 4.7 years. Six sports were included: olympic shooting, long-distance running, hockey, kayaking, artistic gymnastics, and weightlifting. Muscle mass (MM) was estimated by Lee's equation (Lee et al. 2000), in kg, as a % of weight, in kg in relation to height squared (MMI, kg/m2) and by allometric muscle mass index (AMMI, kg/mb, Canda 2022) relative to height (H), arm span (A-S), sitting height (S-T), biacromial breadth (BIAC) and tibial height (T-H). The mean, male vs. female, was: MM, 33.6 ± 4.4 kg vs. 23.1 ± 2.8 kg; 45.9 ± 3.7% vs. 39.7 ± 3.7%; MMI, 10.92 ± 1.35 vs. 8.63 ± 0.89; AMMIH 12.92 ± 1.57 vs. 11.04 ± 1.12; AMMIA-S, 14. 00 ± 1.61 vs. 12.10 ± 1.24; AMMIS-T, 38.69 ± 4.41 vs. 28.96 ± 2.88; AMMIBIAC, 154.76 ± 15.08 vs. 95.89 ± 9.23; AMMIT-H, 79.14 ± 9.93 vs. 54.65 ± 5.92. Males achieved higher values (p < 0.01) in all variables and modalities. ANOVA (p < 0.001) gave differences between modalities in all indices. Weightlifting had the highest mean in kg and indices, while the highest muscle percentage was found among artistic gymnastics. The lowest mean in kg and indices was in long distance races and in percentage in Olympic shooting. Allometric indices can be useful tools for the assessment and estimation of muscle mass regardless of the size of the athlete and in relation to the modality practiced.

Effect of the Skill, Gender, and Kick Order on the Kinematic Characteristics of Underwater Undulatory Swimming in the Dorsal Position.

Backstroke swimmers display the greatest contribution of underwater kicking during the swimming race distances, but, surprisingly, there is little evidence of how kicking kinematics in the dorsal position should be performed. The aim of the present study was to examine the kinematic characteristics of competitive swimmers during underwater undulatory swimming in the dorsal position, with special attention to the swimmers' gender, the level of skill, and kick order. Forty-one national-level swimmers (27 females and 14 males) were filmed from an underwater lateral view while performing a 25-m backstroke from a push start, and they were divided into fast and slow groups according to their kicking velocity. Direct linear algorithms were employed to reconstruct the two-dimensional kinematic characteristics of the first and final kicks of the underwater section. There were no differences between males and females in kicking performance when data were normalised to the swimmers' height. However, swimmers in the fast-kicking group were distinguished by a greater kicking frequency (η2: 0.15) and specific segmental kinematics related to a lower knee range of motion. Swimmers decreased kicking velocity (η2: 0.47) in addition to the kicking frequency (η2: 0.31) and length (η2: 0.16), but increased the kicking amplitude (η2: 0.11) between the first and the final kicks. Changes in kicking segmental kinematics were more related to modification in body orientation during the underwater trajectory than to the kicking motion itself. These results provide the first solid evidence of how swimmers should kick for better performance in dorsal underwater swimming.

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

Short-track speed skating race distances of 500, 1000, and 1500 m that last ∼40seconds to ∼2.5minutes 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. 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. 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. 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.

Pacing Strategy of 800 m and 1500 m Freestyle Swimming Finals in the World Championships According to the Performance in Males and Females of Different Age Groups

Pacing strategy refers to the distribution of effort and speed throughout the race to achieve optimal performance. This study aims to understand whether the choice of pacing strategy in swimming depends on the length of competitions and how sex, age, and performance level influence this strategy. Participants were the finalists of the 800 m and 1500 m freestyle events at the elite and junior world championships in 2022–2023. Race outcomes and pacing parameters were compared between the two distances and across different groups of swimmers. Swimmers in both distances did not break world records. Pacing strategy generally followed a U-shape with significant differences in the frequency and duration of speed changes between the two distances. The 800 m exhibited more frequent changes in acceleration, while the 1500 m events generally followed a more consistent time-series pattern. There were differences in pacing strategies between males and females and between junior and elite swimmers. Swimmers closer to world records showed more consistent pacing patterns compared to those farther from records. This study suggests that pacing strategies are influenced by race distance, sex, age, and performance level. The research highlights the complex interplay between physiological and psychological factors that shape a swimmer’s decision-making during a race.

Comparing the Performance Gap Between Males and Females in the Older Age Groups in IRONMAN® 70.3: An Internet-Based Cross-Sectional Study of More Than 800,000 Race Records

BackgroundThe sex difference in the three split disciplines (swimming, cycling, and running) and overall race times in triathlon races has mainly been investigated for the Olympic distance and IRONMAN® triathlon formats, but not for the half IRONMAN® distance, i.e., the IRONMAN® 70.3. The aim of the present study was to investigate the sex differences in IRONMAN® 70.3 by age group in 5-year intervals for the split disciplines of this race. Data from 823,459 records (625,393 males and 198,066 females) of all age group finishers (in 5-year intervals) competing in all official IRONMAN® 70.3 races held worldwide between 2004 and 2020 were analyzed, and sex differences by age group and split disciplines were evaluated.ResultsMales were faster than females in all split disciplines and all age groups. The sex difference was lower in swimming than in cycling and running and less pronounced for triathletes between 20 and 50 years of age. After the age of 60 years, females were able to reduce the sex difference to males in swimming and cycling, but not in running, where the reduction in the sex difference started after the age of 70 years. The lowest sex difference was in the age group 75 + years for swimming and cycling and in the age group 30–34 years for running. Across age groups, the sex difference was U-shaped in swimming and running, with an increase after 18–24 years in swimming and after 40–44 years in running. In contrast, the sex difference decreased continuously with the increasing age for cycling.ConclusionsIn conclusion, the study found that the sex difference in performance decreases with age in the IRONMAN® 70.3 race distance. However, females did not outperform males at older ages. Notably, sex differences were observed across different disciplines, with swimming displaying lower differences compared to cycling and running. These findings underscore the complex interplay between age, sex, and performance in endurance sports, emphasizing the need for additional research to understand the factors influencing these differences.

Pacing Variation in Multistage Ultramarathons: Internet-Based Cross-Sectional Study.

Ultramarathon running is the most popular ultraendurance competition in terms of the number of races and runners competing annually worldwide; however, no study has compared pacing and performance over a long period. This study analyzes the pacing of successful finishers and nonfinishers in multistage ultramarathons worldwide. A total of 4079 athletes (men=3288; women=791) competing in 99 multistage ultramarathon events from 1983 to 2021 were analyzed, including the number of participants, age, gender, rank, and running speed of successful finishers. The results showed a significant increase in the number of events (n=338) and a significant increase in the number of finishers and nonfinishers (n=5575) in the ultramarathons worldwide during this period. The general linear models (GLMs) of pacing variation showed nonsignificant effects for gender (F1,36.2=2.5; P=.127; ηp2=0.063) and age group (F10,10=0.6; P=.798; ηp2=0.367), but it showed a significant interaction (gender × age) effect (F10,2689=2.3; P=.008; ηp2=0.009). Post hoc analyses showed that men have a higher pacing variation than women in the under 30 years (U30), U35, U45, and U50 groups. Additionally, the fastest women's age group (U35) had the lowest pacing variation. The GLM of pacing variation by gender and event distance showed significant effects for both gender (F1,3=18.5; P<.001; ηp2=0.007) and distance (F2,3=20.1; P<.001; ηp2=0.015). Post hoc analyses showed a growing pacing variation with increasing race distance for both men and women. In addition, men had a higher variation in long events. Furthermore, there was a significant main effect for both genders (F1,3=33.7; P<.001; ηp2=0.012) and rank (F1,3=136.6; P<.001; ηp2=0.048) on performance, with men being faster than women. Pacing varied greatly due to gender (F1,3=4.0; P=.047; ηp2=0.001), with a lower (ie, more even) pacing variation for male athletes in the top 3 finishers. Male nonfinishers showed a higher performance than female nonfinishers (F1,1340=25.6; P<.001), and no difference was identified for pacing variation (F1,789=1.5; P=.228) based on gender. In addition, a weak but significant correlation (r=-0.130; P<.001) was identified between the average running speed and pacing variation for both female and male nonfinishers. In summary, multistage ultramarathon competitions showed an increasing number of competitors and a higher performance challenge. Men have a higher pacing (ie, less even) variation than women, especially observed in longer events. A higher pacing variation was associated with lower performance for men, women, and nonfinishers.

Elderly female ultra-marathoners reduced the gap to male ultra-marathoners in Swiss running races

Recent studies showed that female runners reduced the performance gap to male runners in endurance running with increasing age and race distance. However, the investigated samples were generally small. To investigate this further, the present study examined sex differences by age across various race distances (5, 10 km, half-marathon, marathon, and ultra-marathon) using a large dataset of over 1,100,000 race records from Switzerland over two decades (1999–2019). The study explored performance and participation disparities between male and female runners by employing diverse methods, such as descriptive statistics, histograms, scatter and line plots, correlations, and a predictive machine learning model. The results showed that female runners were more prevalent in shorter races (5, 10 km, half-marathon) and outnumbered male runners in 5 km races. However, as the race distance increased, the male-to-female ratio declined. Notably, the performance gap between sexes reduced with age until 70 years, after which it varied depending on the race distance. Among participants over 75 years old, ultra-marathon running exhibited the smallest sex difference in performance. Elderly female ultra-marathoners (75 years and older) displayed a performance difference of less than 4% compared to male ultra-marathoners, which may be attributed to the presence of highly selected outstanding female performers.

Patellofemoral Pain Syndrome Is Associated With Chronic Disease and Allergies in 60 997 Distance Runner Race Entrants: SAFER XXX Study.

Patellofemoral pain syndrome (PFPS) is a common running-related injury. Independent risk factors associated with PFPS have not been described in a large cohort of distance runners. Descriptive, cross-sectional study. 21.1 and 56 km Two Oceans Marathon races (2012-2015). 60 997 race entrants. Participants completed a compulsory prerace medical screening questionnaire (history of PFPS in the past 12 months, n = 362; no injury history, n = 60 635). Selected risk factors associated with a history of PFPS were explored using univariate & multivariate analyses: demographics, training/running variables, history of chronic diseases (composite chronic disease score), and any allergy. Prevalence ratios (PRs, 95% confidence intervals). Risk factors associated with PFPS (univariate analysis) were increased years of recreational running (PR = 1.09; P = 0.0107), older age (>50 years), and chronic diseases (PR > 2): gastrointestinal disease (PR = 5.06; P < 0.0001), cardiovascular disease (CVD) (PR = 3.28; P < 0.0001), nervous system/psychiatric disease (PR = 3.04; P < 0.0001), cancer (PR = 2.83; P = 0.0005), risk factors for CVD (PR = 2.42; P < 0.0001), symptoms of CVD (PR = 2.38; P = 0.0397), and respiratory disease (PR = 2.00; P < 0.0001). Independent risk factors (multivariate analysis) associated with PFPS (adjusted for age, sex, and race distance) were a higher chronic disease composite score (PR = 2.68 increased risk for every 2 additional chronic diseases; P < 0.0001) and a history of allergies (PR = 2.33; P < 0.0001). Novel independent risk factors associated with PFPS in distance runners are a history of multiple chronic diseases and a history of allergies. Identification of chronic diseases and allergies should be considered as part of the clinical assessment of a runner presenting with a history of PFPS.

Genetic improvement of speed across distance categories in thoroughbred racehorses in Great Britain

Several studies over recent decades have reported a lack of contemporary improvement in thoroughbred racehorse speed, despite apparent additive genetic variance and putatively strong selection. More recently, it has been shown that some phenotypic improvement is ongoing, but rates are low in general and particularly so over longer distances. Here we used pedigree-based analysis of 692,534 records from 76,960 animals to determine whether these phenotypic trends are underpinned by genetic selection responses, and to evaluate the potential for more rapid improvement. We show that thoroughbred speed in Great Britain is only weakly heritable across sprint (h2 = 0.124), middle-distance (h2 = 0.122) and long-distance races (h2 = 0.074), but that mean predicted breeding values are nonetheless increasing across cohorts born between 1995 and 2012 (and racing from 1997 to 2014). For all three race distance categories, estimated rates of genetic improvement are statistically significant and also greater than can be explained by drift. Taken together our results show genetic improvement for thoroughbred speed is ongoing but slow, likely due to a combination of long generation times and low heritabilities. Additionally, estimates of realised selection intensities raises the possibility that the contemporary selection emerging from the collective actions of horse breeders is weaker than previously assumed, particularly over long distances. We suggest that unmodelled common environment effects may have upwardly biased estimates of heritability, and thus expected selection response, previously.

Association of myostatin gene polymorphism with echocardiographic and muscular ultrasonographic measurements in Hungarian thoroughbreds horses

The g.66493737C/T polymorphism of the myostatin gene (MSTN) majorly influences muscle fiber composition and best race distance of Thoroughbreds. Thus, a better understanding of this process may lead to superior genetic exploitation for maximizing Thoroughbred athletic potential.Our objective is to investigate whether myostatin genotypes are associated with muscular development and cardiac variables of Thoroughbreds. Echocardiography and muscular ultrasonography were performed on three groups having C/C, C/T, and T/T genotypes, respectively. Each group consisted of 22 animals. Homogeneity of variance between the groups was checked by Levene's test. Multivariate analysis of variance was applied to determine differences in measured variables vs. MSTN genotypes. Fascicle length of anconeus and thickness of triceps brachii muscles showed significant differences between C/C and T/T genotypes (pFascicle-length-of-anconeus = 0.004, pthickness-of-triceps-brachii < 0.001). According to the primary outcome, there are associations between myostatin genotypes and cardiac variables. Aortic diameter at the sinus of Valsalva (end-diastole and end-systole) and aortic diameter at the valve (end-systole) indicated significant differences between C/C and T/T genotypes (paortic-diameter-at-the-sinus-of-Valsalva-end-diastole = 0.015, paortic-diameter-at-the-sinus-of-Valsalva-end-systole = 0.011, paortic-diameter-at-the-valve-end-systole = 0.014). Pearson correlation effect sizes were rFascicle-length-of-anconeus = 0.460, rthickness-of-triceps-brachii = 0.590, raortic-diameter-at-the-sinus-of-Valsalva-end-diastole = 0.423, raortic-diameter-at-the-sinus-of-Valsalva-end-systole = 0.450, and raortic-diameter-at-the-valve-end-systole = 0.462. C/C genotypes gave 22.1, 12.2, 6.3, 6.0, and 6.7% higher values compared to T/T genotypes, respectively. Differences regarding aortic diameter between genotype groups support the hypothesis that C/C animals have consequently increased cardiac output and aerobic capacity.

Optimally controlling nutrition and propulsion force in a long distance running race.

Runners competing in races are looking to optimize their performance. In this paper, a runner's performance in a race, such as a marathon, is formulated as an optimal control problem where the controls are: the nutrition intake throughout the race and the propulsion force of the runner. As nutrition is an integral part of successfully running long distance races, it needs to be included in models of running strategies. We formulate a system of ordinary differential equations to represent the velocity, fat energy, glycogen energy, and nutrition for a runner competing in a long-distance race. The energy compartments represent the energy sources available in the runner's body. We allocate the energy source from which the runner draws, based on how fast the runner is moving. The food consumed during the race is a source term for the nutrition differential equation. With our model, we are investigating strategies to manage the nutrition and propulsion force in order to minimize the running time in a fixed distance race. This requires the solution of a nontrivial singular control problem. As the goal of an optimal control model is to determine the optimal strategy, comparing our results against real data presents a challenge; however, in comparing our results to the world record for the marathon, our results differed by 0.4%, 31 seconds. Per each additional gel consumed, the runner is able to run 0.5 to 0.7 kilometers further in the same amount of time, resulting in a 7.75% increase in taking five 100 calorie gels vs no nutrition. Our results confirm the belief that the most effective way to run a race is to run approximately the same pace the entire race without letting one's energies hit zero, by consuming in-race nutrition. While this model does not take all factors into account, we consider it a building block for future models, considering our novel energy representation, and in-race nutrition.

Risk Factors for Epistaxis in Thoroughbred Flat Races in Japan (2001-2020).

We investigated the risk factors for epistaxis in Japanese flat races over a 20-year period. The veterinary records of horses identified as having epistaxis by endoscopy on the race day, and the official racing records of all flat races from April to September between 2001 and 2020, were reviewed. The racecourses (n = 10), surface type, surface condition, race class, race distance, race year, sex, age, two training centers, ambient temperature, and body weight on race days were assessed using multivariable logistic regression (p < 0.05). Of 475,709 race starts, 616 (1.30 cases per 1000 starts; 95% confidence interval [CI], 1.20-1.40) included an epistaxis event. Nine variables were significantly associated with epistaxis. Seven of the variables have been reported in previous studies: lower ambient temperature, soft surface conditions, shorter racing distances (≤1400 m), increasing age, females and geldings compared to males, training center, and race year. However, two novel variables were identified as significantly associated with epistaxis, increasing body weight per 20 kg (p < 0.001, odds ratio [OR], 1.33; 95% CI, 1.25-1.41) and the racecourses that the horses were running at (p < 0.001, especially Sapporo [OR; 4.74, 95% CI, 3.07-7.31], Hakodate [OR, 4.66; 95% CI, 3.05-7.11], and Kokura [OR, 4.14; 95% CI, 2.65-6.48] compared to the reference racecourse [Kyoto]). These results can facilitate developing interventions to reduce epistaxis in flat racing.

Psychophysiological changes in uphill runners

The increasing popularity of street racing combined with the psychophysical demands of racing competitions present new challenges for sports mental health. The objective of this study was to investigate psychophysiological changes after an uphill race. Twenty-three runners were recruited, eleven men (35 ± 5.6 years; 1.7 ± 0.2 m; 76.6 ± 10 kg; 11.5 ± 4.5% fat) and twelve women (39 ± 9.2 years; 1.61 ± 0.1 m; 58.8 ± 3.8 kg; 20.1 ± 3.1% fat), who participated in an uphill race (distance 24.6 km, altimetry 2142 m, slope 11%, temperature 13°C, humidity 97%). Every runner was submitted to evaluations, physiological, muscular strength and mental health, before and after of the race. After an uphill race, there was a significant decrease (p &lt; 0.05) in muscle resistance (22%), power (27%) and force (30%). There was a significant increase (p&lt; 0.05) in lactate levels (100%) and perceived effort (200%). Regarding mental health, there was a reduction (p&lt;0.05) in anxiety (competitive 10% and trace 40%) and a significant increase (p&lt; 0.05) in self-esteem (29%) and Happiness (43%). We conclude that after an uphill race there is a significant increase in the alterations in the psychophysiology, improving the mental health of runners.

Innovatív genomikai és élettani kutatások az angol telivér állomány versenyteljesítményének fokozása érdekében

Összefoglalás. Célkitűzés: Miosztatin (MSTN) genotípusok összefüggés-vizsgálata izomfejlődéssel és cardiovascularis paraméterekkel angol telivérekben. Módszer: Három, MSTN-genotipizált csoportban echokardiográfiát és izomultrahangot végeztünk. Adatainkat SPSS 15.0 szoftverrel elemeztük. Eredmények: A C/C csoport mért izomvastagságai 22,08 (p = 0,004) és 12,24 (p &amp;lt; 0,001) %-kal; a cardiovascularis rendszeré 6,33 (p = 0,015), 6,03 (p = 0,011) és 6,72 (p = 0,014) %-kal magasabb volt, mint a T/T genotípusnál. Pearson-féle R: anconeus pólyahossz r = 0,460; triceps r = 0,590; aorta Valsalva-öböl diasztolé r = 0,423, szisztolé r = 0,450, billentyűk síkjában szisztolé r = 0,462. Következtetések: Az eredmények hozzájárulnak a galopplovak hatékony tréningmódszereinek kidolgozásához, így jelentősen befolyásolható eredményességük. Summary. Background: The myostatin gene (MSTN; g.66493737) C/T polymorphism has great influence on the development of the muscles and the rates between the types of muscle fibers as well as cardiovascular performance in thoroughbred horses. Consequently MSTN gene decisively determines the optimal race distance and racing ability in thoroughbreds through the muscle development regulation. A more detailed understanding of these genetic attributions and their associations leads us to be able to maximise the athletic potential of thoroughbreds. Objective: In this paper the relationships were investigated between the MSTN genotypes and muscle development or the main cardiovascular parameters which affect or define the cardiac performance of thoroughbreds. Methods: Ultrasonography and echocardiography was performed on each individual selected for our study. Sixty-six thoroughbreds were applied in each measurement (22 of each genotype, C/C, C/T and T/T). All of them participated at different races or were trained at the same time in Hungary. A portable MyLab™ ultrasound system (Alfa-Vet, Animal Healthcare Ltd.) was used for the measurements. To investigate the development of the candidate muscles the size of the anconaeous and triceps brachii muscles were used as indicators. The length of the mentioned muscles was given by the size of the total length of the muscle fascia (m. fasciae anconeus and m. fasciae triceps brachii). Thickness was measured at the largest anatomical diameter of the muscles. To characterize the cardiovascular system, the diameter of the Valsalva sinus of the aorta was measured at the end of diastole and systole, respectively, as well as the diameter of the aorta in the plane of the semilunar valves. The data were analyzed with the SPSS 15.0 for Windows software. Homogeneity of variance between groups was checked with Levene’s test and multivariate analysis of variance was used to determine the correlations between the measured variables and the myostatin genotypes. Results According to our measurements relationship was detected between individual myostatin genotypes, muscular development and cardiovascular parameters of the thoroughbreds. The muscle thickness and fascicle length of group C/C of MSTN showed significant differences compared to group T/T. Aortic diameter at the sinus of Valsalva (end-diastole and end-systole) and aortic diameter at the valve (end-systole) also indicated significant differences between C/C and T/T genotypes too. The thickness of the two muscles (anconaeous and triceps brachii) in the group C/C was 2.08 (p=0.004) and 12.24 (p&amp;lt;0.001) % higher; and of the parameters of cardiovascular system were 6.33 (p=0.015), 6.03 (p=0.011) and 6.72 (p=0.014) % greater, respectively, than in the T/T genotypes. Conclusions: The results contribute to a better understanding of the effects of MSTN genetic variations on phenotypes, which help to develop new, effective training methods for racehorses in order to prepare them for their best race distance according to their genotypes. Thus, the competitive performance and racing ability of thoroughbreds can be improved significantly.

Risk factors for, and prediction of, exertional heat illness in Thoroughbred racehorses at British racecourses

The development of exertional heat illness (EHI) is a health, welfare and performance concern for racehorses. However, there has been limited multivariable assessment of the possible risk factors for EHI in racehorses, despite such information being vital for regulators to effectively manage the condition. Consequently, this study aimed to identify the risk factors associated with the occurrence of EHI in Thoroughbred racehorses and assess the ability of the risk factor model to predict the occurrence of EHI in racehorses to assist in early identification. Runners at British racecourses recorded in the British Horseracing Authority database between 1st July 2010 and 30th April 2018 were used to model the probability that a horse would present with EHI as a function of a suite of environmental, horse level and race level factors. EHI was reported in 0.1% of runners. Race distance, wet bulb globe temperature, preceding 5-day temperature average, occurrence of a previous EHI incident, going, year and race off time were identified as risk factors for EHI. The model performed better than chance in classifying incidents with a mean area under the receiver operating characteristic curve score of 0.884 (SD = 0.02) but had a large number of false positives. The results provide vital evidence for industry on the need to provide appropriate cool down facilities, identify horses that have repeated EHI incidents for early intervention, and collect new data streams such as on course wet bulb globe temperature measurements. The results are especially relevant as the sport is operating in a changing climate and must mitigate against more extreme and longer spells of hot weather.

A Simulation Investigation on the Dynamic Behavior of Wheelset Bearings Caused by Wheel Diameter Difference

AbstractA bearing‐vehicle‐track coupling dynamic model is built in this paper and the validity of the model is proved by comparing the simulation data with the theoretical data. Based on this model, the influence of wheel diameter difference (WDD) on the dynamic behavior of wheelset bearing is studied. The results demonstrate that when the bogie has a rear WDD, lateral displacement (LaD) of the front wheelset is the smallest. When the bogie has an anti‐phase WDD, LaD of the rear wheelset is the smallest, while when the bogie has an in‐phase WDD, LaD of the front and rear wheelsets is the largest, and LaD of the front and rear WDD is between the two, which is in line with the theoretical analysis results. Compared with LaD results of the wheelset bearing outer raceway under normal conditions, when the wheel has a diameter difference, LaD distance of the outer race increases with the WDD increasing, and the frequency of lateral movement also increases with the increase against the WDD gradation. The high‐frequency and large‐distance lateral movement of the wheelset bearing outer race under the WDD will increase the roller‐outer raceway force, and accelerate the failure of the bearing.

Changes in pacing variation with increasing race duration in ultra-triathlon races

Despite the increasing scientific interest in the relationship between pacing and performance in endurance sports, little information is available about pacing and pacing variation in ultra-endurance events such as ultra-triathlons. Therefore, we aimed to investigate the trends of pacing, pacing variation, the influence of age, sex, and performance level in ultra-triathlons of different distances. We analysed 969 finishers (849 men, 120 women) in 46 ultra-triathlons longer than the original Ironman® distance (e.g., Double-, Triple-, Quintuple- and Deca Iron ultra-triathlons) held from 2004 to 2015. Pacing speed was calculated for every cycling and running lap. Pacing variation was calculated as the coefficient of variation (%) between the average speed of each lap. Performance level (i.e., fast, moderate, slow) was defined according to the 33.3 and 66.6 percentile of the overall race time. A multivariate analysis (two-way ANOVA) was applied for the overall race time as the dependent variable with ‘sex’ and ‘age group’ as independent factors. Another multivariate model with ‘age’ and ‘sex’ as covariates (two-way ANCOVA) was applied with pacing variation (cycling and running) as the dependent variable with ‘race’ and ‘performance level’ as independent factors. Different pacing patterns were observed by event and performance level. The general pacing strategy applied was a positive pacing. In Double and Triple Iron ultra-triathlon, faster athletes paced more evenly with less variation than moderate or slower athletes. The variation in pacing speed increased with the length of the race. There was no significant difference in pacing variation between faster, moderate, and slower athletes in Quintuple and Deca Iron ultra-triathlon. Women had a slower overall performance than men. The best overall times were achieved at the age of 30–39 years. Successful ultra-triathlon athletes adapted a positive pacing strategy in all race distances. The variation in pacing speed increased with the length of the race. In shorter ultra-triathlon distances (i.e., Double and Triple Iron ultra-triathlon), faster athletes paced more evenly with less variation than moderate or slower athletes. In longer ultra-triathlon distances (i.e., Quintuple and Deca Iron ultra-triathlon), there was no significant difference in pacing variation between faster, moderate, and slower athletes.

Data analysis and qualitative assessment of 5000 meter male middle distance runners

Sports and games has a great importance in education and also in maintaining health and fitness. To develop endurance, one may include middle distance run in their daily fitness activities. The 5000-meters middle distance running events are contested at all global athletics championships including India. The purpose of the paper is to analyze the pacing strategies of foreign elite male athlete and Indian male athlete in 5000-meter middle distance race. The study is to exhibit whether split 100 meter times of 5000-meter are varied in between foreign elite male athlete and Indian male athlete. Ten male leading foreign athletes are selected as foreign athletes from readily publically available data of the International Association of Athletic Federation (IAAF) World Athletics Championship 2017, World Athletics Championship 2019 and ten male Indian athletes are selected as Indian athletes from the Association of Indian Universities (AIU) All India Inter University Athletics Championship 2020. The research brings forth how the variations occurs among the Indian athletes of Male population and foreign athlete of Male population. The constant variation in their running pace, velocity of the foreign athletes is exhibited in accordance with their distance parameter including the distance coverages world championship from 100 meter to 5000 meter.

Running Endurance in Women Compared to Men: Retrospective Analysis of Matched Real-World Big Data.

To determine whether the gap in endurance performance between men and women is reduced as distances increase, i.e. if there is a sex difference in endurance, one can analyse the performance of elite runners, all participants, or one can pair women and men during short-distance events and examine the difference over longer distances. The first two methods have caveats, and the last method has never been performed with a large dataset. This was the goal of the present study. A dataset including 38,860 trail running races from 1989 to 2021 in 221 countries was used. It provided information on 1,881,070 unique runners, allowing 7251 pairs of men and women with the same relative level of performance to be obtained, i.e. the same percentage of the winner time of the considered race on short races (25-45km-effort) that were compared during longer races (45-260km-effort). The effect of distance on sex differences in average speed was determined using a gamma mixed model. The gap between sexes decreased as distance increases, i.e. men's speed decreased by 4.02% (confidence interval 3.80-4.25) for every 10km-effort increase, whereas it decreased by 3.25% (confidence interval 3.02-3.46) for women. The men-women ratio decreases from 1.237 (confidence interval 1.232-1.242) for a 25km-effort to 1.031 (confidence interval 1.011-1.052) for a 260km-effort. This interaction was modulated by the level of performance, i.e. the greater the performance level of the runner, the lower the difference in endurance between sexes. This study shows for the first time that the gap between men and women shrinks when trail running distance increases, which demonstrates that endurance is greater in women. Although women narrow the performance gap with men as race distance increases, top male performers still outperform the top women.

Association between sociodemographic factors and mobility limitation among older adults: a systematic review and meta-analysis protocol

BackgroundMobility is an independent predictor of physical functionality, healthy ageing, and quality of life. Various literatures have associated mobility limitation in older adulthood with demographic and socioeconomic factors. Hence, we propose a systematic review and meta-analysis to synthesise the association between sociodemographic factors and mobility limitations in older adults.Methods and analysesThis protocol was written according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines. We will perform a comprehensive search of all observational studies that assessed the relationship between age, gender, race, place, education, income, occupation, social status, and walking distance, time, or speed. Electronic databases (MEDLINE, Web of Science, EMBASE, CINAHL, AgeLine, and SPORTDiscus) will be searched from inception to 28 February 2023. We will supplement the database search by manually searching the reference lists of all identified and relevant full-text articles. Two independent reviewers will be responsible for screening articles, data extraction, and assessment of bias. We will appraise the study quality and risk of bias using the Prediction Model Risk of Bias Assessment Tool (PROBAST). A meta-analysis will be considered if data from the selected studies are homogeneous, otherwise, a narrative synthesis of the extracted data will be presented.DiscussionMobility limitation leads to frequent falls, dependency, morbidity, and death among older adults. This review is necessary, to identify and prioritise important sociodemographic factors during older adults’ clinical assessment and policy development. It is the first phase of a multi-methods study seeking to develop a prognostic mobility trajectory for community-dwelling older adults.Systematic review registrationPROSPERO CRD42022298570