Running Race Research Articles

AimThis study aimed to investigate the determinants of running performance in a cross-country running race and examine whether running economy and biomechanics are affected. Moreover, we analyzed whether the magnitude of change in running economy (RE) is related to changes in biomechanics, performance, and fitness measures.MethodThirteen runners (12 male and 1 female), with an average 10 km personal best time of 36:46 ± 3:17 (min:s), participated in the 30 km cross-country race, Lidingöloppet. Assessments of submaximal and maximal running physiology, biomechanics, and anthropometry were conducted before and immediately after the race. A multiple linear regression model was applied to explain performance variance. Pearson’s correlation analyses examined the relationships between performance and pre-test variables, and between changes in running economy and both pre-test fitness measures and changes in biomechanics. Paired Student’s t-tests were used to compare pre- and post-race values.ResultsPerformance was best explained using a model including oxygen uptake at lactate threshold (LT), fat utilization, and allometrically scaled running economy (R2 = 0.918, adjusted R2 = 0.887, F = 29.7, p < 0.01). Race performance also correlated with maximal oxygen uptake (VO2max, r = −0.776, p = 0.003), fat mass (r = 0.646, p = 0.032), and velocity at VO2max (vVO2max, r = −0.853, p < 0.01). The oxygen cost of running increased (201.8 ± 14 vs. 208.4 ± 9.3 mL kg−1·km−1; p = 0.041), whereas respiratory exchange ratio (0.91 ± 0.04 vs. 0.85 ± 0.05; p < 0.01) and body mass (69.2 ± 7.5 vs. 67.6 ± 7.7 kg; p < 0.01) decreased post-race. Energetic cost of running (0.997 ± 0.076 vs. 1.015 ± 0.052 kcal kg−1·km−1; p = 0.192) and all biomechanical measurements, including cadence, contact time, overstride, vertical displacement, and vertical force, were unaffected by the race. The magnitude of change in running economy was related only to pre-test running economy (r = −0.749; p = 0.003) but not to performance (r = −0.440; p = 0.132), other pre-test fitness measures, or any changes in biomechanics.ConclusionThe best performance prediction model included oxygen uptake at estimated lactate threshold, fat utilization during submaximal running, and allometrically scaled running economy. Oxygen cost of running increased post-race, likely due to increased fat oxidation, despite decreased body mass. No changes in biomechanics were observed, and changes in running economy could not be explained by changes in biomechanics. Aerobic fitness, anthropometry, and performance were not associated with changes in running economy. Given the small and relatively homogeneous sample, findings should be considered exploratory, although they suggest that practitioners may benefit from targeting fat oxidation, oxygen uptake at the estimated lactate threshold, and running economy in training.

Pacing in ultra-triathlon has been investigated by analyzing lap times from Double to Deca Iron ultra-triathlon for World Cup races but not for a World Championship. The present study aimed to investigate pacing in ultra-triathletes competing in the fastest and largest World Championship in Quintuple Iron ultra-triathlon ever held in history. A total of 11 female and 24 male finishers who completed the 2024 Quintuple Ultra Triathlon World Championship in Colmar, France, were analyzed. Independent t-tests assessed sex-based performance variations with effect sizes (Cohen's d). A two-way ANOVA evaluated the effects of sex and performance quartiles on cycling and running, with eta squared (η²) used to measure effect sizes. Overall, men were slower in swimming and cycling and faster in running and overall race time. The variability in lap times was similar in cycling for both women and men but higher in running for women. There was a significant interaction between sex and performance quartiles in cycling but not running. For cycling, the variability in performance was higher in men compared to women; for running, it was similar for both women and men. The finding that women outperformed men in swimming and cycling, likely due to the elite nature of the World Championship, which featured a highly selected and committed female cohort with a high completion rate. While both sexes showed consistent pacing in cycling, women exhibited greater variability in running, possibly due to more frequent breaks.

BackgroundPacing in ultra-triathlon has been investigated by analyzing lap times from Double to Deca Iron ultra-triathlon for World Cup races but not for a World Championship. The present study aimed to investigate pacing in ultra-triathletes competing in the fastest and largest World Championship in Quintuple Iron ultra-triathlon ever held in history.MethodsA total of 11 female and 24 male finishers who completed the 2024 Quintuple Ultra Triathlon World Championship in Colmar, France, were analyzed. Independent t-tests assessed sex-based performance variations with effect sizes (Cohen’s d). A two-way ANOVA evaluated the effects of sex and performance quartiles on cycling and running, with eta squared (η²) used to measure effect sizes.ResultsOverall, men were slower in swimming and cycling and faster in running and overall race time. The variability in lap times was similar in cycling for both women and men but higher in running for women. There was a significant interaction between sex and performance quartiles in cycling but not running. For cycling, the variability in performance was higher in men compared to women; for running, it was similar for both women and men.ConclusionsThe finding that women outperformed men in swimming and cycling, likely due to the elite nature of the World Championship, which featured a highly selected and committed female cohort with a high completion rate. While both sexes showed consistent pacing in cycling, women exhibited greater variability in running, possibly due to more frequent breaks.

This study investigates how fractal complexity affects Trail and mountain running (TMR) race course measurements at varying GPS resolutions and emphasizes the need for standardized course measurement protocols. GPX files from 34 UTMB World Series race courses, including final events in Chamonix, were analyzed. Horizontal distance, elevation gain, km-effort, and fractal complexity were computed at varying GPS spatial resolutions (0.2–100 m). Elevation data were refined using a 20-cm resolution Digital Elevation Model (DEM) to ensure consistency across the dataset. The courses were systematically resampled and compared to assess the effects of spatial resolution on race measurements and classifications. The findings reveal that a decrease in GPS spatial resolution significantly reduces measured distances and elevation gains. Discrepancies in kilometer-effort reached up to 14% (mean = 7.0%, SD = 3.8%), horizontal distance up to 6.3% (mean = 2.9%, SD = 1.5%), and elevation gain up to 32% (mean = 14.0%, SD = 9.5%). Adopting a 1-m resolution, chosen for its practical balance between capturing terrain complexity at a human scale and computational efficiency, would enhance the reliability of distance, elevation gain, and km-effort calculations, ensuring fairer race classifications and improved comparability across events.

Russia has gained large experience in arranging sport events of different scale. Big sport competitions of international level were held, such summer Universiade ‘Kazan-2013’ and winter Universiade in Krasnoyarsk in 2019, a number of world championships and biggest mega-sport events: the 22nd Olympic Games and 11th Paralympics in Sochi and Football World Cup FIFA ‘Russia-2018’. Changes in the country have cut the possibility of arranging sport events of this level on the territory of the Russian Federation. It is necessary to mention that many sport events, such as Super Bowl, NHL and NBA competitions that show the maximum viewings and profits are national championships. On the background of big sport problems, a rise in the number of international events of mass sport is evident, they are mainly organized by private initiatives. Data of VCIOM sociological research and statistic information presented a profile of potential participant of mass sport events. It is a man at the age of 37, who prefers endurance competitions. Such sports as steeplechase, running, triathlon, swimming and ski race are the most popular in this segment of competitions. Apart from strategic goals, sport events have a certain economic potential. The potential economic capacity of 4-days competition with the average number of participants and accompanying people makes up 16.2 m euros or 1.766 B rubles. The article studies several organizational-economic models typical of different sectors of sport competitions. The author shows that potential economic effect of big sport events is much higher, however, this effect is not always attained in full. For competitions of mass sport social effect is more typical.

Background: Long-distance running impacts many organ systems. Aside from musculoskeletal and cardiopulmonary events, the gastrointestinal and renal system as well as metabolic homeostasis and electrolyte balance can be affected. A respective medical support strategy enabling rapid diagnosis, triage, and treatment in the context of large sports events is thus of utmost importance. Incidents can be assessed and graded via point-of-care (POC) blood gas analysis (BGA). We thus aimed to evaluate the feasibility and benefits of its use during a large sports event. Methods: All documented patient contacts during the race of the Vienna City Marathon (VCM) 2023 were retrospectively assessed. Additionally, the BGAs conducted in all patients requiring intravenous access were analyzed. Data are presented in a descriptive manner. Results: There were 39,871 participants at the VCM 2023. Of these, 277 (0.7%) required medical support, localized most commonly in the finishing area of the race (n = 239, 86% of all incidents). Fifty-eight (20.9%) patients had to be hospitalized. The most frequent chief complaints were syncope or collapse (24.9%), followed by general pain (20.6%) and trauma (14.8%). Five patients (1.8%) suffered from seizures, and one experienced (0.4%) from spontaneous pneumothorax. Thirty-one patients (11.2%) received venous blood gas analyses, showing mean creatinine levels of 1.82 (±0.517) mg/dL, mean lactate concentrations of 6.03 (±4.5) mmol/L, mean pH of 7.42 (±0.0721), and a mean base excess of -0.72 (±3.72) mmol/L. No cases of hyponatremia occurred in the documented samples. In eight cases (25.8%), sodium concentrations were above 145 mmol/L, with a maximum of 149 mmol/L. No cardiac arrests occurred. Conclusions: The physical exertion during the assessed long-distance running race resulted in numerous contacts with the medical support teams. The use of POC BGA at a large-scale marathon event was shown to be easy and feasible, allowing for more extensive diagnostics on-site. It can be integrated into a medical support strategy and might be beneficial for decision-making regarding patient triage, treatment, hospitalization, or patient discharge.

In ultrarunning events, energy substrates are important due to the long duration of the event. However, anorexia that occurs during the event can pose a challenge to nutritional strategy(1). The risk of dehydration due to limited access to fluid is increased in trail running, but the association between dehydration and appetite loss due to reduced fluid intake is unclear. This study aims to clarify the relationship between exercise-induced appetite loss and dehydration during prolonged physical activity. The study included 47 healthy adults who provided prior consent and participated in a trail running race with a distance of 169 km and a cumulative elevation of 10,500 m. Dehydration status was ascertained by Urine Specific Gravity (USG), and fluctuations in hydration status were tracked through the race. Subjects with no missing data (n = 40) were classified into severely dehydrated (n = 33) if ≥ 1.030 or mildly dehydrated (n = 7) if &lt; 1.030 based on USG at the finish line(2). Subjective evaluation of anorexia level and gastrointestinal condition was made in a post-race self-administered questionnaire, in which symptoms were rated on a 5-point scale for each race segment. In this questionnaire, participants were also asked to indicate the amount of food and water they consumed during the race. The parameters measured before the race, at the mid-race aid station, and at the finish line, as well as the responses provided in the questionnaire for each race segment, were analysed using a two-way ANOVA with factors for group and time. Multiple comparisons were performed to examine differences across time points and between groups. The mean USG at the finish line was 1.027 ± 0.002 in the mildly dehydrated group and 1.034 ± 0.003 in the severely dehydrated group, both showing a significant increase from before the race, with the severely dehydrated group being higher (p &lt; 0.0001). Body weight decreased significantly in both groups by the finish line, with no difference. There was no significant difference in the rank between groups (p = 0.36). 57.9% of participants experienced appetite loss, but there was no difference in the frequency of appetite loss during the race between the group (p = 1.000, Fisher’s Exact Test), the severely dehydrated group exhibited increasing symptom levels as the race progressed. There was a tendency for the severely dehydrated group to have a higher frequency of nausea during the race (p = 0.095). Fluid intake was similar between groups, both in total and per hour. The results of this study suggested that dehydration and appetite loss are independent incidents and that appetite loss has not been a cause of dehydration. Dehydration in runners during 160km trail running races may have caused appetite loss by producing nausea(3).

More than 29 million participants completed marathons and half-marathons in the US between 2010-2023, approximately 3 times the number from 2000-2009. Contemporary long-distance race-related cardiac arrest incidence and outcomes are unknown. To determine the incidence and outcomes of cardiac arrests during US marathons and half-marathons between 2010-2023 from a record of race finishers and a comprehensive review of cases from media reports, direct contact with race directors, USA Track & Field claims, and interviews with survivors or next of kin. Observational case series from the Race Associated Cardiac Event Registry; cohort data from US marathon and half-marathon runners from January 1, 2010, to December 31, 2023. Case profiles were reviewed to determine etiology and factors associated with survival. Incidence and etiology data were compared with historical reference standards (2000-2009). Recreational long-distance running (marathon and half-marathon distance). Incidence proportions of sudden cardiac arrest and death. Among 29 311 597 race finishers, 176 cardiac arrests (127 men, 19 women, 30 sex unknown) occurred during US long-distance running races. Compared with 2000-2009, cardiac arrest incidence remained unchanged (incidence rate, 0.54 per 100 000 participants [95% CI, 0.41-0.70] vs 0.60 per 100 000 [95% CI, 0.52-0.70], respectively). However, there were significant declines in cardiac death incidence (0.20 per 100 000 [95% CI, 0.15-0.26] vs 0.39 per 100 000 [95% CI, 0.28-0.52]) and case fatality rate (34% vs 71%). Cardiac arrests remained more common among men (1.12 per 100 000 [95% CI, 0.95-1.32]) than women (0.19 per 100 000 [95% CI, 0.13-0.27]) and during the marathon (1.04 per 100 000 [95% CI, 0.82-1.32]), compared with the half-marathon (0.47 per 100 000 [95% CI, 0.38-0.57]). Among runners for which a definitive cause of cardiac arrest could be determined (n = 67/128 [52%]), coronary artery disease rather than hypertrophic cardiomyopathy was the most common etiology. Decreased cardiopulmonary resuscitation time and an initial ventricular tachyarrhythmia rhythm were associated with survival. Despite increased participation in US long distance running races, cardiac arrest incidence remains stable. There has been a marked decline in cardiac arrest mortality, and coronary artery disease was the most common etiology among cases with sufficient cause-related data. Effective emergency action planning with immediate access to defibrillation may explain the improvement in survival.

Pacing has been investigated in different running races, including ultra-marathons. We have, however, little knowledge about pacing in ultra-trail running. To date, no study has investigated pacing in one of the most iconic ultra-trail running races, the ‘Western States 100-Mile Endurance Run’ (WSER), which covers 160 km (100 miles) and includes significant elevation changes (6000 vertical meters uphill and 7500 vertical meters downhill). Therefore, the aim of the study was to investigate pacing for successful finishers in WSER regarding gender, age, and performance level. Official results and split times for the WSER were obtained from the race website, including elevation data from 3837 runners, with 3068 men (80%) and 769 women (20%) competing between 2006 and 2023. The mean race speed was calculated for each participant, as well as the average mean checkpoint speed for each of the 18 race checkpoints (17 aid stations and finish point). The percentage of change in checkpoint speed (CCS) in relation to the average race speed was calculated. CCS was calculated for each of the 18 checkpoints to evaluate each runner’s pacing strategy. The average change in checkpoint speed (ACCS) of each participant was calculated as a mean of the 18 CCSs. Eight age groups were formed. Since there were very few runners younger than 25 and older than 65 years, these age groups were merged into < 30 and 60 > groups, respectively. Four performance groups were formed by four quartiles, each consisting of 25% of the total sample separately for men and women. Pacing shows great variability between checkpoints in both men and women, mainly influenced by elevation. Although the race profile is mostly downhill, it appears that the pacing trend is towards positive pacing. The differences between men and women were mainly at the beginning of the race (men start faster) and towards the end (men slow down more). Men have more pacing variability than women, with significant differences in the youngest age group, as well as the 40–44 and 50–54 age groups. In addition, younger men have more variability in pace compared to older men. There are no significant differences in age groups in women. Finally, the slowest and fastest ultra runners had less pacing variability than medium level runners. Pacing in WSER-runners shows great variability between checkpoints in both men and women. Pacing is positive and highly influenced by elevation. Men start faster than women, and men slow down more than women. Pacing differs in male but not in female age group runners. The slowest and fastest ultra runners had less pacing variability than medium level runners.

Red blood cell (RBC) senescence and blood rheology during ultraendurance running events appear to be affected differently depending on the race distance. The physiological mechanisms underlying these differences are poorly understood. We investigated the effects of three different ultra-trail running races performed in La Reunion Island (Mascareignes, "the 70 km," 70 km/4000 m D+; Trail Du Bourbon, "the 100 km," 100 km/6090 m D+; Diagonale des Fous, "the 170 km," 170 km/10,500 m D+) on RBC oxidative stress, RBC senescence, and blood rheology in 66 finishers (18 "70 km," 24 "100 km," and 24 "170 km"). We observed a decrease in RBC antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, and catalase) positively related to the race distance and an increase in RBC H 2 O 2 and isoprostane levels after the three races. However, RBC H 2 O 2 and isoprostane levels were found to be higher after the 70-km race compared with the 170-km and the 100-km races. RBC phosphatidylserine externalization increased over baseline value after the 70-km race only. Chymotrypsin-like and trypsin-like activities of the RBC proteasome were decreased after all races compared with before. RBC-derived microparticles (RBC-MP) were increased after the 170-km and the 70-km races. Despite increased RBC senescence markers, RBC deformability increased after the three races. Blood viscosity was differently affected by the three races with a decrease at low shear rate after the two longest races (the 170 km and the 100 km) and an increase at high shear rate after the shortest one (the 70 km). Our results confirm that ultraendurance running events differently affect RBC senescence markers and blood viscosity depending on the race distance and suggest that RBC oxidative stress could play a key role in the observed alterations.

It is well known that elite athletes of specific ethnicities and/or nationalities dominate certain sports disciplines (e.g., East Africans in marathon running). However, we do not know the nationalities of the fastest non-professional IRONMAN triathletes. Therefore, this study intended to identify the fastest athletes by country of origin competing in IRONMAN triathlon events, focusing on non-professional age group triathletes. Data from all IRONMAN age group athletes competing worldwide between 2002 and 2022 in all official IRONMAN races were collected. Sex, age group, country of origin of the athletes, location and year of the event, split times, overall race times, and transition times were obtained. Additionally, the dataset was augmented with specific data (i.e. event characteristics such as temperatures for water and air and course characteristics for all three split disciplines) related to the different race locations. We limited the analysis to the top 150 countries by participation (i.e. countries with at least 13 successful finishers records in the sample). A total of 677,320 records of IRONMAN age group triathletes originating from 150 different countries and participating in 443 races over 65 different locations were analyzed. European countries such as Germany, Austria, Denmark, Belgium, Switzerland, Norway, Czechia, Estonia, and Slovenia have the fastest IRONMAN age group athletes. IRONMAN Hawaii, IRONMAN Vitoria-Gasteiz and IRONMAN Hamburg are the fastest races. Hilly running and cycling race courses led to slower race times, while flat surfaces, rolling cycling and ocean swimming led to faster race times. Optimal water temperatures were found at 23–25 °C and optimal air temperature ranged between 19–21 and 25–28 °C. The fastest IRONMAN age group triathletes from European countries such as Germany, Austria, Denmark, Belgium, Switzerland, Norway, Czechia, Estonia, and Slovenia. With the presented results for optimal air and water temperatures and description of the optimal cycling and running course characteristics, IRONMAN age group athletes might be able to select an IRONMAN race with the best conditions in order to achieve a fast IRONMAN race time.

PurposeFatigue is an inevitable phenomenon during distance running, leading to the adoption of altered gait patterns by runners. Therefore, the aim of this study was to investigate the changes in gait variability and fatigability in distance runners over a 10-km running race.MethodsFor this aim, 12 runners (36.5 ± 5.4 y) completed a simulated 10-km running race. Throughout the trial, heart rate (HR) and rate perceived exertion (RPE, CR-10) were analyzed. In addition, kinematic/kinetic measurements: contact time (CT), flight time (FT), step length (SL), stride time (ST) leg (kvert) and vertical (kleg) stiffness, were recorded. Gait variability including phase coordination index (PCI) was calculated for each 2-km segment.ResultsHR increased (from 88.46 ± 5.84 to 93.87 ± 6.48 %HRMAX, P < 0.05) as well as RPE (6.58 ± 0.47–8.96 ± 0.40 a.u., P < 0.001) as the distance increased. Conversely, no differences between running segments for the kinematic/kinetic data (CT–FT–SL–ST–kvert–kleg) were observed over five 2 km. However, there was increase (P < 0.05) in gait variability (PCI), over the course of the running race. Furthermore, the determination coefficient (R2) was found as strong and very strong when compared five (0–10 km) and four (4–10 km) running segments between HR–RPE and PCI (R2 = 0.623–0.845).ConclusionThese results suggest that the gait variability is one mechanical determinant in assessing the neuromuscular output when the fatigability increases during a running race.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00421-025-05780-8.

The primary aims of this study were to determine acute and longitudinal relationships between static flexibility measures and running economy(RE). Seventy-one healthy recreational runners (34 males/37 females, age: 36.4 [12.4]y, body mass index: 23.3 [3.1]kg/m2) completed an aerobic fitness assessment (VO2max) based on self-selected half-marathon race pace (RP) and flexibility testing (standing toe-touch test and weight-bearing lunge test) at baseline and 2 to 3weeks prior to an endurance running or multisport race (70 [21]d apart). Participants resumed self-selected training and physical activity between laboratory visits. Hierarchical linear regressions were used to assess relationships between flexibility and RE across timepoints, and pre-post changes in flexibility and RE. Interactions between age and flexibility, and experience and flexibility were also investigated. No significant differences (P > .05) were found between flexibility measurements and RE at RP from visit 1 to visit 2, nor were there any significant associations between RE at RP and scores on the weight-bearing lunge test or standing toe-touch test. However, there was a significant interaction between age and the weight-bearing lunge test on RE at RP (ß = -0.0270, P = .018) such that older runners with less flexibility and younger runners with greater flexibility were less economical at RP at baseline. Our findings suggest that reduced flexibility may decrease the energetic cost of running for older runners to a greater extent than it does for younger runners. When prescribing run training intensity and mileage, coaches and clinicians working with masters runners should be cognizant of the potential performance benefits of decreased ankle joint flexibility as well as the overall greater risk of calf injury in this population. Future research should consider the underlying mechanism by which age enhances the beneficial effects of decreased flexibility on RE.

In world-class middle- and long-distance running races, a Wavelight signal has recently been used as a pacing guide for setting records. The aim of the present study was to compare performance and psychophysiological effects between light-guided, drafting, and nonassisted pacing conditions in distance runners. Fifteen male middle- and long-distance runners of national and regional standard ran three 5000-m time trials in a counterbalanced order with the following pacing distribution: the first 4000m and last 1000m were covered at submaximal and maximal intensities, respectively. The 3 trials (conditions) were (1)self-paced, (2)guided by a light signal, and (3)guided by a cyclist in front (drafting condition). Pace, heart rate, rating of perceived exertion, and affective valence were recorded every 500m. No statistically significant differences were found between pacing-light and self-paced conditions. Running time was shorter in the drafting versus self-paced condition in the final 500-m section (P = .031; d = 0.76). No differences were found between drafting and light conditions. Similarly, whereas 9 out of 10 significant differences in terms of lower heart rate, or rating of perceived exertion, or higher affective valence responses were found in the drafting versus self-paced condition (P = .004-.041; d = 0.63-1.39), only 4 were found across the tests in the drafting versus light condition (P = .005-.016; d = 0.66-0.84). Light-guided pacing did not influence performance or psychophysiological responses in distance runners during a 5000-m test, but drafting produced a large effect.

Marketing Mix Factors and the Attitudes of Road Race Running Event Organizers After the COVID-19 Pandemic in Thailand

Agility appears to be an important skill in the downhill sections of trail running; however, its actual role in the performance of this sport is unknown. The aim of the study was to evaluate the correlation of reactive agility (RA) and certain biomechanical parameters with the performance of runners when performing trail running descents. Nine amateur trail runners (four women and five men) performed a session of change of direction, RA, and 15 m linear sprint tests. In a second session, they performed a trail running race of 400 m with a negative elevation gain of 40 m. The relationship between the variables obtained in both sessions was evaluated using Pearson’s correlation coefficient. The results revealed significant correlations of performance during the trail running descent, with the time of the 15 m linear sprint (r = 0.77, ρ ≤ 0.05.), 5 m linear sprint (r = 0.79, ρ ≤ 0.05.), and with the reaction time in the reactive agility test with a sport-specific stimulus (r = 0.82, ρ ≤ 0.05.). The correlations found in the tests suggest that reactive agility skills and acceleration abilities have a significant relationship with performance on downhill sections in trail running.

ABSTRACT The purposes of this study were 1) to investigate if cytokines were increased following a running road-race, and 2) to examine associations between cytokines and hyperthermia. Seventy-seven recreational runners participated in this study which occurred at the 7-mile race in the heat (ambient temperature, 25.0–26.7°C; %RH, 56.7–79.0 ± 5.0%). Before and following the race, blood draws were performed to measure circulating inflammatory cytokines. Core temperature was measured using an ingestible thermistor throughout the race. Core temperature was significantly higher at post-race (39.5 ± 0.7°C) than pre-race (36.9 ± 0.4°C, p < 0.001). IL-6, IL-8, and IL-10 significantly increased at post-race (IL-6, 48.0 ± 22.3 pg⋅ml−1; IL-8, 63.8 ± 23.9 pg⋅ml−1; IL-10, 29.2 ± 20.0 pg⋅ml−1) compared to pre-race (IL-6, 28.4 ± 13.6 pg⋅ml−1; IL-8, 53.2 ± 19.4 pg⋅ml−1; IL-10, 18.6 ± 11.9 pg⋅ml−1, p < 0.001). A greater increase in core temperature pre- to post-race was predicted by the faster finish time, a greater increase in IL-6, and greater body mass loss during the race (r2 = 0.298, p < 0.001). Small associations were found between IL-8 and core temperature at post-race (r = 0.255, p = 0.025). In conclusion, cytokines concentrations and core temperature increased following the race. Moreover, post-race hyperthermia is associated with increased IL-6, faster finish times, and higher body mass losses.

Background: Men represent about 95% of Sudden Cardiac Death (SCD) that occur during sport activity. This over representation of men during exercise-related SCD which remains true even after adjustment for sport participation is not explained by biological and physiological factors. We hypothesized that male psychology and related behavioral responses might play a role in this over-representation. Methods: Data comes from the Paris Sudden Death Expertise Center. We collected the data from the last 10 years on the three most important running races in Paris: half marathon (HM), full marathon (FM) and 20 km. We analyzed the potential acceleration during the last km in men and women (only available for the HM (445,000 participations)), compared with the speed recorded during the previous 5km, each subject being its own control. We assessed the exact location of the SCD cases for each race. Using Artificial Intelligence (AI) and the electronic health record systematically collected for each subject in France (all drugs prescriptions, examinations and medical diagnoses), we assessed their theoretical risk for SCD. Results: Over the last 10 years and among the 1.2 million participants (mean age 38 ±11y, 71.6 % of males), there were 17 SCD (7 in 20km, 5 HM and 5 in FM). Of these, 88% (15/17) were men, with an average age of 42±13y. Incidence in men was 3-fold higher than women (16.9 vs 5.7 cases per million participations, p&lt;1/1000). CPR was initiated by a bystander for 15 subjects ( 88.2%). Initial shockable rhythm was present in 13 subjects (76.5%). All 17 subjects were transported to hospital, either with a return of spontaneous circulation (15 (88.2%)) or in a refractory state (2 (11.8%)). At hospital discharge, 14 (82.4%) were alive with a very good neurological outcome (CPC1). Among all participants, 87%accelerated during the last km, during which 65% (11/17) of SCDs occurred (Figure 1). Compared with the previous 5km, women's speed varied little compared with men's over the last km (Figure 2). Among those who accelerated the most (&gt;2 km/h) in the last km, the proportion of men was 1.96 times (CI 1.86-2.06) higher than that of women. On the basis of their medical history all but one of the subjects were considered as low risk for SCD by the IA algorithm. Conclusion: Although direct causality cannot be proven, men’s attitude and behavioral reactions to competition could partly explain their over-representation in sport-related SCD.

During some trail running races, athletes have to carry hydration support, food, and technical and safety equipment, which generates an additional load that must be mobilized during the race. The aim of the present study was to determine the physiological responses to overload running and the effect they may have on metabolic zones. Seventeen well-trained male trail runners (n = 17) completed three maximal treadmill tests with weighted vests at 0%, 5%, and 10% of their body mass (L0, L5, and L10). Their gas exchange was monitored to assess their ventilatory thresholds 1 (VT1) and 2 (VT2), maximal fat oxidation zone (FatMax), and peak oxygen consumption (VO2peak). Their heart rate (HR), power, and velocity (V) were tracked to compare their behavior. One-way ANOVA showed significant differences in the V (p < 0.001; ηp2 = 0.4620) as a limitation for reaching the peak velocity (Vpeak), with a significant decrease in the Vpeak with the L10 compared to the L0 (p = 0.002) and L5 (p = 0.004). In addition, one-way ANOVA showed significant differences in the peak absolute power (p < 0.001; ηp2 = 0.468) among the groups, detecting higher power production between the L10 and L0 (p < 0.001) and between the L10 and L5 (p = 0.015). Loads higher than L5 could generated important physiological and mechanical modifications, while a load of L5 managed to maintain the working conditions without overloading. These insights shed light on nuanced strategies for optimizing performance and endurance, offering valuable considerations for athletes seeking to enhance their training regimens during overload conditions.

During city running or marathon races, shifts in level ground and up-and-down slopes are regularly encountered, resulting in changes in lower limb biomechanics. The longitudinal bending stiffness of the running shoe affects the running performance. This research aimed to investigate the biomechanical changes in the lower limbs when transitioning from level ground to an uphill slope under different longitudinal bending stiffness (LBS) levels in running shoes. Fifteen male amateur runners were recruited and tested while wearing three different LBS running shoes. The participants were asked to pass the force platform with their right foot at a speed of 3.3 m/s ± 0.2. Kinematics data and GRFs were collected synchronously. Each participant completed and recorded ten successful experiments per pair of shoes. The range of motion in the sagittal of the knee joint was reduced with the increase in the longitudinal bending stiffness. Positive work was increased in the sagittal plane of the ankle joint and reduced in the keen joint. The negative work of the knee joint increased in the sagittal plane. The positive work of the metatarsophalangeal joint in the sagittal plane increased. Transitioning from running on a level surface to running uphill, while wearing running shoes with high LBS, could lead to improved efficiency in lower limb function. However, the higher LBS of running shoes increases the energy absorption of the knee joint, potentially increasing the risk of knee injuries. Thus, amateurs should choose running shoes with optimal stiffness when running.