Detection of endotoxins from selected drinking water microbiota using an LAL-based assay and its implications for human health.

Endotoxins are pyrogenic lipopolysaccharides from Gram-negative bacteria that are known to induce fever, septic shock, and multiple organ failure, posing a substantial risk to human health. Drinking water systems are especially prone to home microbiomes containing a large variety of Gram-negative bacteria. Consumption of water from these systems in developed countries is generally regarded as non-hazardous to humans due to the low number of non-pathogenic bacterial cells per milliliter and oral admission. To assess potential risks posed by endotoxins in drinking water systems, we conducted a conventional microbiological investigation on a local community water system in the north of Germany and mined the resulting data to investigate the endotoxin contents of some of the most abundant microbiota found during these analyses. Using a Limulus amoebocyte lysate (LAL) -based endotoxin detection method, average normalized endotoxin content was determined. Although the average culturable amounts of microbiota in the drinking water system were insufficient to exert endotoxin levels critical to human health, peaks and acute contaminations may pose substantial health risks.

Cycling Intensity Effect on Running Plus Cycling Performance among Triathletes.

Running performance is crucial for triathlon performance. However, the prior bout of cycling may affect the running split time. This study compared the triathletes' cycling plus running (C+R) time, when cycling was performed at three different intensities and running was maximal. A total of 38 athletes (21 males and 17 females) were included. Body composition, maximal oxygen uptake, and functional threshold power (FTP) was evaluated. The participants visited the laboratory three times to cycle 20 km at 80%, 85%, or 90% FTP (in randomized order) and run 5 km as fast as possible. Males ran faster after cycling at 80% FTP than after cycling at 90% FTP (mean difference=35.1 s; CI% 2.2, 68.1 s; p=0.035). The C+R time was faster when cycling at 90% FTP than at 80% FTP (mean difference=57.7 s; CI% 26.1, 89.3 s; p<0.001). For females, no significant difference was observed in the running time after cycling at 80%, 85%, or 90% FTP. The C+R time was faster when cycling at 90% FTP than at 80% FTP (mean difference=80.9 s; CI% 29.7, 132.1 s; p=0.002). In conclusion, to optimize triathlon performance, male and female athletes should cycle at a minimum of 90% FTP.

Critical Analysis of Information Provided by ChatGPT on Lactate, Exercise, Fatigue, and Muscle Pain: Current Insights and Future Prospects for Enhancement.

This study aimed to critically evaluate the information provided by ChatGPT on the role of lactate in fatigue and muscle pain during physical exercise. We inserted the prompt: "What is the cause of fatigue and pain during exercise?" using ChatGPT versions 3.5 and 4o. In both versions, ChatGPT associated muscle fatigue with glycogen depletion and "lactic acid" accumulation, while pain was linked to processes such as inflammation and microtrauma. We deepened the investigation with ChatGPT 3.5, implementing user feedback to question the accuracy of the information about lactate. The response was then reformulated, involving a scientific debate about the true role of lactate in physical exercise and debunking the idea that it is the primary cause of muscle fatigue and pain. We also utilized the creation of a "well-crafted prompt", which included persona identification and thematic characterization, resulting in much more accurate information in both the ChatGPT 3.5 and 4o models, presenting a range of information from the physiological process of lactate to its true role in physical exercise. The results indicated that the accuracy of the responses provided by ChatGPT can vary depending on the data available in its database and, more importantly, on how the question is formulated. Therefore, it is indispensable that educators guide their students in the processes of managing the AI tool to mitigate risks of misinformation.

Changes in the attractiveness of medical careers and career determinants during the bachelor's program at Zurich medical schools.

BACKGROUND: Monitoring the career intentions of medical students during their undergraduate studies could help to address the shortage of physicians, particularly in general practice. This study aimed to investigate changes in medical students' career openness, attractiveness and determinants of medical career choice during their bachelor's studies. METHODS: The design was cross-sectional, recruiting all medical students who started a bachelor's program in one of the four different educational tracks in Zurich, Switzerland, in the fall of 2019 (first survey) and completed it in the summer of 2022 (second survey). Students' perceptions of the attractiveness and determinants of different medical career options were assessed using a structured online questionnaire. Absolute changes between the two-time points were reported in percentage points overall and by educational track. Regression analysis was used to examine the association of student characteristics and determinants of career options with the attractiveness of each option. RESULTS: We surveyed 354 medical students at the beginning and 433 at the end of the bachelor's program (participation rate: 71.1% and 86.9%, respectively). Overall, the proportion of students open to all proposed medical career options decreased (from 52.8% to 43.8%, p = 0.004). The attractiveness of outpatient gynecology or pediatrics increased (from 27.4% to 43.4%, p < 0.001), whereas the attractiveness of both general and specialized inpatient care decreased (from 47.8% to 40.3%, p = 0.05 and from 71.1% to 61.1%, p = 0.006 respectively). There was an increase in the proportion of students who perceived part-time work, autonomy and relationships with patients as important career determinants (from 47.3% to 64.7%, p < 0.001; from 63.3% to 77.8%, p < 0.001; from 80.8% to 89.3%, p = 0.002 respectively), while the importance of reputation and career opportunities decreased (from 42.6% to 26.2%, p < 0.001; from 79.2% to 63.6%, p < 0.001 respectively). The importance of part-time work and relationships with patients were positively associated with the attractiveness of general practice. CONCLUSIONS: During the bachelor's program, the attractiveness of a career in general practice tended to decrease, but the importance of part-time work, autonomy and relationships with patients as career determinants increased. Helping students understand how these determinants relate to general practice may increase their interest in the profession. TRIAL REGISTRATION: Not applicable.

Running Variability in Marathon-Evaluation of the Pacing Variables.

Background and Objectives: Pacing analyses for increasingly popular long-distance running disciplines have been in researchers' spotlight for several years. In particular, assessing pacing variability in long-distance running was hardly achievable since runners must repeat long-running trials for several days. Potential solutions for these problems could be multi-stage long-distance running disciplines. Therefore, this study aimed to assess the long-distance running variability as well as the reliability, validity, and sensitivity of the variables often used for pacing analyses. Materials and Methods: This study collected the split times and finish times for 20 participants (17 men and three women; mean age 55.5 years ± 9.5 years) who completed the multiday marathon running race (five marathons in 5 days), held as part of the Bretzel Ultra Tri in Colmar, France, in 2021. Seven commonly used pacing variables were subsequently calculated: Coefficient of variation (CV), Change in mean speed (CS), Change in first lap speed (CSF), Absolute change in mean speed (ACS), Pace range (PR), Mid-race split (MRS), and First 32 km-10 km split (32-10). Results: Multi-stage marathon running showed low variability between days (Intraclass correlation coefficient (ICC) > 0.920), while only the CV, ACS, and PR variables proved to have moderate to good reliability (0.732 < ICC < 0.785). The same variables were also valid (r > 0.908), and sensitive enough to discern between runners of different performance levels (p < 0.05). Conclusions: Researchers and practitioners who aim to explore pacing in long-distance running should routinely utilize ACS, CV, and PR variables in their analyses. Other examined variables, CS, CSF, MRS, and 32-10, should be used cautiously. Future studies might try to confirm these results using different multi-stage event's data as well as by expanding sensitivity analysis to age and gender differences.

Prevalence of fear of COVID-19, depression, and anxiety among undergraduate students during remote classes.

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, undergraduate students were exposed to symptoms of psychological suffering during remote classes. Therefore, it is important to investigate the factors that may be generated and be related to such outcomes. OBJECTIVE: To investigate the association between fear of COVID-19, depression, anxiety, and related factors in undergraduate students during remote classes. METHODS: This cross-sectional study included 218 undergraduate students (60.6% women and 39.4% men). Students answered a self-administered online questionnaire designed to gather personal information, pandemic exposure, physical activity level, fear of COVID-19 using the 'Fear of COVID-19 Scale', symptoms of depression using the Patient Health Questionnaire-9, and anxiety using General Anxiety Disorder-7. RESULTS: Undergraduate students had a high prevalence of depression and anxiety (83.0% and 76.1%, respectively) but a low prevalence of fear of COVID-19 (28.9%) during remote classes. Multivariate analysis revealed that women who reported health status as neither good nor bad and who had lost a family member from COVID-19 had the highest levels of fear. For depression and anxiety, the main related factors found were female gender, bad health status, insufficiently active, and complete adherence to the restriction measures. CONCLUSION: These findings may be used to develop actions to manage symptoms of anxiety and depression among students, with interventions through physical activity programmes to improve mental health.

Effects of High-Intensity Warm-Up on 5000-Meter Performance Time in Trained Long-Distance Runners.

Warm-up protocols with high intensities before continuous running provide potential benefits for middle-distance runners. Nevertheless, the effect of high-intensity warm-ups on long-distance runners remains unclear. The purpose of this study was to verify the effect of a high-intensity warm-up protocol on 5000 m performance in trained runners. Thirteen male runners (34 ± 10 years, 62 ± 6 kg, 62.7 ± 5.5 ml/kg/min) performed two 5000 m time trials, preceded by two different warm-ups. One high-intensity warm up (HIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (100% of the running intensity) and one low-intensity warm up (LIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (70% of the running intensity)), where the running intensities were calculated using the results obtained in the Cooper test. Physiological and metabolic responses, and endurance running performance parameters, were evaluated by the Counter Movement Jump (CMJ), running rating of perceived exertion (RPE), blood lactate concentration (BLa), and performance running. Total time for the 5000 m was lower using HIWU when compared to LIWU (1141.4 ± 110.4 s vs. 1147.8 ± 111.0 s; p = 0.03; Hedges' g = 0.66). The HIWU warm-up led to an improvement in pacing strategy during the time trial. After warm-up protocols, the performance on the CMJ was improved only when applying HIWU (p = 0.008). Post warm-up BLa was significantly higher for HIWU vs. LIWU (3.5 ± 1.0 mmol·L-1 vs. 2.3 ± 1.0 mmol·L-1; p = 0.02), with similar behavior for the RPE (p = 0.002), internal load of the session (p = 0.03). The study showed that a high-intensity warm-up protocol can improve performance in the 5000 m in trained endurance runners.

Trends in Participation, Sex Differences and Age of Peak Performance in Time-Limited Ultramarathon Events: A Secular Analysis.

Background and Objectives: Increases in the number of participants in time-limited ultra-marathons have been reported. However, no information is available regarding the trends in participation, performance and age in 12 h and 24 h time-limited events. The aim of the study was to describe the trends in runners' participation, performance and age in 12 h and 24 h ultra-marathons for both sexes and to identify the age of peak performance, taking into account the ranking position and age categories. Materials and Methods: The sample comprised 210,455 runners in time-limited ultra-marathons (female 12 h = 23,706; female 24 h = 28,585; male 12 h = 61,594; male 24 h = 96,570) competing between 1876 and 2020 and aged 18 to 86 years. The age of peak performance was tested according to their ranking position (first−third; fourth−tenth and >tenth position) and taking into account their running speed in different age categories (<30 years; 31−40 years; 41−50 years; 51−60 years; >60 years), using the Kruskal−Wallis test, followed by the Bonferroni adjustment. Results: An increase in the number of participants and a decrease in running speed were observed across the years. For both events, the sex differences in performance decreased over time. The sex differences showed that male runners performed better than female runners, but the lowest differences in recent years were observed in the 24 h ultra-marathons. A positive trend in age across the years was found with an increase in mean age ("before 1989" = 40.33 ± 10.07 years; "1990−1999" = 44.16 ± 10.37 years; "2000−2009" = 45.99 ± 10.33 years; "2010−2020" = 45.62 ± 10.80 years). Male runners in 24 h races were the oldest (46.13 ± 10.83 years), while female runners in 12 h races were the youngest (43.46 ± 10.16 years). Athletes ranked first−third position were the youngest (female 12 h = 41.19 ± 8.87 years; female 24 h = 42.19 ± 8.50 years; male 12 h = 42.03 ± 9.40 years; male 24 h = 43.55 ± 9.03 years). When age categories were considered, the best performance was found for athletes aged between 41 and 50 years (female 12 h 6.48 ± 1.74 km/h; female 24 h 5.64 ± 1.68 km/h; male 12 h 7.19 ± 1.90 km/h; male 24 h 6.03 ± 1.78 km/h). Conclusion: A positive trend in participation in 12 h and 24 h ultra-marathons was shown across the years; however, athletes were becoming slower and older. The fastest athletes were the youngest ones, but when age intervals were considered, the age of peak performance was between 41 and 50 years.

The Sex Difference in 6-h Ultra-Marathon Running-The Worldwide Trends from 1982 to 2020.

Background and Objectives: The 6-h ultra-marathon is the shortest time-limited ultra-marathon race, but little has been investigated regarding this race format. Previously, only the age of peak performance in the context of longer time-limited ultra-marathons was determined. The purpose of this study was to investigate the trends in 6-h ultra-marathon races from 1982 to 2020 for female and male ultra-runners, the participation and performance by countries, the age of peak performance, and the differences in performance regarding countries. Materials and Methods: The sample included 23,203 female ultra-runners, aged 18-83 years, and 87,264 male ultra-runners, aged 18-85 years, who were finishers in a 6-h ultra-marathon held between 1982 and 2020. The age of peak performance was tested using the Kruskal-Wallis test, followed by the Bonferroni Correction. The difference in performance by countries was verified using a linear regression model with the fastest runners from Russia in women, and Tunisia in men, used as reference. Results: Over the years, the men-to-women ratio decreased. The mean age was 43.20 ± 9.30 years for female and 46.09 ± 10.17 years for male runners. Athletes in younger age groups were faster than athletes in older age groups. Most female and male participants originated from Germany. Women from Russia (10.01 ± 1.28 km/h) and men from Tunisia (12.16 ± 1.46 km/h) were the fastest. Conclusions: In summary, in 6-h ultra-marathons held between 1982 and 2020, the participation for both women and men increased, while the men-to-women ratio decreased. The mean age was higher in men compared to women. Most female and male runners originated from Germany, but the fastest women were from Russia, and the fastest men from Tunisia. Future studies need to investigate whether Russian women and Tunisian men are also the best in other distance-limited ultra-marathon races, such as 12-h and 24-h.

Fear of failure in Brazilian runners.

This study aims to investigate the fear or failure (FoF) in Brazilian runners of both sex, performance levels and age categories, as well as to verify the relationship between FoF and socioeconomic status (SES). Sample size as composed by 916. Age, sex, body height, body weight, SES, and running pace were self-reported. The Multidimensional Questionnaire of FoF was applied in an online platform. Running pace, and SES were categorized and processed through multivariate analysis and Spearman correlations, with the p-value set at 0.05. Female runners with better performance (2.13 ± 0.74) and younger (2.16 ± 0.80), as a well as male runners with worse performance (2.04 ± 0.69) and older (2.04 ± 0.89) presented the highest values of FoF. Among women, SES was negatively associated with FoF (r = -0.144; p = 0.006), while a positive association between running pace and SES was observed among men (r = 0.290; p < 0.001). Non-professional Brazilian runners presented low values of FoF.

Mature and immature platelets during the first week after birth and incidence of patent ductus arteriosus.

BACKGROUND: Thrombocytopenia is a risk factor for patent ductus arteriosus. Immature and mature platelets exhibit distinct haemostatic properties; however, whether platelet maturity plays a role in postnatal, ductus arteriosus closure is unknown. METHODS: In this observational study, counts of immature and mature platelets (=total platelet count - immature platelet count) were assessed on days 1, 3, and 7 of life in very low birth weight infants (<1500 g birth weight). We performed echocardiographic screening for haemodynamically significant patent ductus arteriosus on day 7. RESULTS: Counts of mature platelets did not differ on day 1 in infants with (n = 24) and without (n = 45) haemodynamically significant patent ductus arteriosus, while infants with significant patent ductus arteriosus exhibited lower counts of mature platelet on postnatal days 3 and 7. Relative counts of immature platelets (fraction, in %) were higher in infants with patent ductus arteriosus on day 7 but not on days 1 and 3. Receiver operating characteristic curve analysis unraveled associations between both lower mature platelet counts and higher immature platelet fraction (percentage) values on days 3 and 7, with haemodynamically significant ductus arteriosus. Logistic regression analysis revealed that mature platelet counts, but not immature platelet fraction values, were independent predictors of haemodynamically significant patent ductus arteriosus. CONCLUSION: During the first week of postnatal life, lower counts of mature platelets and higher immature platelet fraction values are associated with haemodynamically significant patent ductus arteriosus. Lower counts of mature platelet were found to be independent predictors of haemodynamically significant patent ductus arteriosus.

Clinical practice audit concerning antimicrobial prophylaxis in paediatric neurosurgery: results from a German paediatric oncology unit.

BACKGROUND: Perioperative antimicrobial prophylaxis (PAP) has been identified as an important target for internal audits, concerning the judicious use of antibiotics. Paediatric oncology patients with brain tumours face an increased risk of surgical site infection (SSI) after neurosurgery and receive routine PAP in this setting. PATIENTS AND METHODS: All patients younger than 18 years admitted to the paediatric oncology centre (POC) with a neurosurgical intervention. Systematic audit of routine clinical data is divided in two groups: retrospective (Jan 01, 2012-March 31, 2014) and prospective (April 01, 2014-March 31, 2015) referring to an internal PAP guideline, invented in Jan. 2014). Surveillance of SSI up to 30 days after the operation with standard criteria (Centres for Disease Control and Prevention, USA). RESULTS: In total, 53 neurosurgical operations were analysed in 33 paediatric oncology patients. Twelve patients received more than one operation. The detailed analysis of PAP revealed prophylactic cefuroxim doses about 30 mg/kg instead of 50 mg/kg and no repeated dosing in operations lasting longer than 4 h. In addition, Cefotaxim, which is not indicated as PAP in neurosurgery, was used instead of Cefuroxim (or Ampicillin-Sulbactam) in 23 % of all cases in the retrospective and 18 % of all cases in the prospective audit. PAP for more than 3 doses (>24 h) was administered in 66 % in the retrospective group and in 60 % in the prospective group (p = n.s.). In both groups, no SSI was detected. DISCUSSION: This first comprehensive audit of PAP in paediatric oncology patients undergoing neurosurgery outlines significant opportunities to improve clinical practice in terms of correct dosing, the correct choice of the antibiotic, a correct timing schedule and a shorter duration of PAP. In addition, our results illustrate in detail the challenges in clinical practice when an evidence-based approach to improve a standard workflow has to be implemented.

Arrhythmia Detection in Pediatric Patients: ECG Quality and Diagnostic Yield of a Patient-Triggered Einthoven Lead-I Event Recorder (Zenicor EKG-2™).

Symptoms that may be caused by arrhythmia are common in pediatric outpatient departments, though it remains challenging to reveal paroxysmal tachycardia. This investigation evaluated prospectively the quality and diagnostic yield of a newly available handheld patient-activated event recorder (ER) in children. In 226 children (pts) aged 0-17 years with or without congenital heart defects, pacemaker/ICDs or arrhythmia, a lead-I ER ECG was created. ER ECGs were recorded by pressing the patients' thumbs on the device and were analyzed in comparison with a lead-12 ECG, as gold standard. Event recording and data transmission were possible in all cases. ECG quality of the ER showed a high accordance in measuring heart rate (ICC = 0.962), duration of QRS complexes (κ = 0.686), and PR interval (ICC = 0.750) (p < 0.001) although P wave detection remained challenging (p = 0.120). 36 % (n = 82) of the pts had heart rhythm disturbances. The ER yielded 92 % sensitivity in diagnosing supraventricular tachycardia plus 77 % sensitivity and 92 % specificity in identifying abnormal ECGs. In children, the application of the tested ER was suitable. ECGs of good quality could be performed and transmitted easily, and also complex arrhythmia analysis was possible. This ER is an excellent diagnostic device for the detection and exclusion of tachycardia in children.

Natural History of Patent Ductus Arteriosus in Very Low Birth Weight Infants after Discharge.

Data on the natural history of infants discharged with patent ductus arteriosus is sparse. We report on the 36-months follow-up after hospitalization in 68 infants discharged with an open ductus arteriosus. Notwithstanding a high spontaneous closure rate, catheter intervention in 5 infants illustrates a critical need for cardiologic follow-up.

Purpura fulminans after therapeutic hypothermia in an asphyxiated neonate with streptococcemia.

OBJECTIVE: Therapeutic hypothermia is an established therapeutic regimen in severely asphyxiated term neonates. The amount of cerebral injury is reduced resulting in an improved neurologic outcome. Therapeutic hypothermia-induced side effects mostly affect the circulatory system, kidney, and liver. However, asphyxia and hypothermia in itself reduce the hemostatic capacity of each individual organism. STUDY DESIGN: A case of a neonate with severe asphyxia and purpura fulminans after hypothermia is described. RESULTS AND CONCLUSION: Although purpura fulminans cannot be attributed to hypothermia solely, the influence of hypothermia on hemostasis may have promoted severe coagulopathy with a fatal outcome. Further studies are necessary to reveal therapeutic hypothermia as a trigger for severe coagulopathies in asphyxiated neonates, especially in those with sepsis and overt coagulopathy prior to therapeutic hypothermia.

Case Report: Differences in self-selected pacing in 20, 40, and 60 ironman-distance triathlons: a case study.

Background: Triathletes are pushing their limits in multi-stage Ironman-distance triathlons. In the present case study, we investigated the pacing during 20, 40, and 60 Ironman-distance triathlons in 20, 40, and 60 days, respectively, of one professional IRONMAN® triathlete. Case study: Event 1 (20 Ironman-distance triathlons in 20 days), Event 2 (40 Ironman-distance triathlons in 40 days), and Event 3 (60 Ironman-distance triathlons in 60 days) were analyzed by discipline (swimming, cycling, running, and overall event time), by Deca intervals (10 days of consecutive Ironman-distance triathlons) and additional data (sleep duration, body mass, heart rate in cycling and running). To test differences between Events and Deca intervals within the same discipline, T-tests (2 groups) or one-way ANOVAs (3 or more groups) were used. Results: Swimming splits were fastest in Event 1, (ii) cycling and running splits were fastest in both Event 2 and 3, (iii) overall speed was fastest in Event 3, (iv) sleep duration increased during Event 2 but decreased in Event 3, (v) body mass decreased in Event 2, but increased in Event 3 and (vi) heart rate during cycling was similar in both Event 2 and 3. In contrast, heart rate during running was greater in Event 3. Conclusion: In a professional IRONMAN® triathlete finishing 20, 40, and 60 Ironman-distance triathlons in 20, 40, and 60 days, respectively, split performances and both anthropometrical and physiological changes such as body mass and heart rate differed depending upon the duration of the events.

Ultra-Cycling- Past, Present, Future: A Narrative Review.

BACKGROUND: Ultra-endurance events are gaining popularity in multiple exercise disciplines, including cycling. With increasing numbers of ultra-cycling events, aspects influencing participation and performance are of interest to the cycling community. MAIN BODY: The aim of this narrative review was, therefore, to assess the types of races offered, the characteristics of the cyclists, the fluid and energy balance during the race, the body mass changes after the race, and the parameters that may enhance performance based on existing literature. A literature search was conducted in PubMed, Scopus, and Google Scholar using the search terms 'ultracycling', 'ultra cycling', 'ultra-cycling', 'ultra-endurance biking', 'ultra-bikers' and 'prolonged cycling'. The search yielded 948 results, of which 111 were relevant for this review. The studies were classified according to their research focus and the results were summarized. The results demonstrated changes in physiological parameters, immunological and oxidative processes, as well as in fluid and energy balance. While the individual race with the most published studies was the Race Across America, most races were conducted in Europe, and a trend for an increase in European participants in international races was observed. Performance seems to be affected by characteristics such as age and sex but not by anthropometric parameters such as skin fold thickness. The optimum age for the top performance was around 40 years. Most participants in ultra-cycling events were male, but the number of female athletes has been increasing over the past years. Female athletes are understudied due to their later entry and less prominent participation in ultra-cycling races. A post-race energy deficit after ultra-cycling events was observed. CONCLUSION: Future studies need to investigate the causes for the observed optimum race age around 40 years of age as well as the optimum nutritional supply to close the observed energy gap under consideration of the individual race lengths and conditions. Another research gap to be filled by future studies is the development of strategies to tackle inflammatory processes during the race that may persist in the post-race period.

Europe has the fastest Ironman race courses and the fastest Ironman age group triathletes.

The majority of participants in Ironman triathlon races are age group athletes. We have extensive knowledge about recreational athletes' training and competition participation. Nonetheless, Ironman age group triathletes must achieve fast race times to qualify for the Ironman World Championship in Hawaii. They can, therefore, benefit from knowing where the fastest Ironman racecourses in the world are. The aim of the present study was to investigate where the fastest Ironman racecourses for age group triathletes are located in the world. Data from 677,702 Ironman age group finishers' records (544,963 from men and 132,739 from women) originating from 228 countries and participating in 444 events across 66 different Ironman race locations between 2002 and 2022 were analyzed. Data was analyzed through traditional descriptive statistics and with machine learning regression models. Four algorithms were tested (Random Forest Regressor, XG Boost Regressor, Cat Boot Regressor, and Decision Tree Regressor). The models used gender, age group, country of origin, environmental factors (average air and water temperatures), and the event location as independent variables to predict the final overall race time. Despite the majority of successful Ironman age group triathletes originating from the USA (274,553), followed by athletes from the United Kingdom (55,410) and Canada (38,264), these countries exhibited average overall race times that were significantly slower compared to the fastest countries. Most of the triathletes competed in Ironman Wisconsin (38,545), followed by Ironman Florida (38,157) and Ironman Lake Placid (34,341). The fastest overall race times were achieved in Ironman Copenhagen (11.68 ± 1.38 h), followed by Ironman Hawaii (11.72 ± 1.86 h), Ironman Barcelona (11.78 ± 1.43 h), Ironman Florianópolis (11.80 ± 1.52 h), Ironman Frankfurt (12.03 ± 1.38 h) and Ironman Kalmar (12.08 ± 1.47 h). The fastest athletes originated from Belgium (11.48 ± 1.47 h), followed by athletes from Denmark (11.59 ± 1.40 h), Switzerland (11.62 ± 1.49 h), Austria (11.68 ± 1.50), Finland (11.68 ± 1.40 h) and Germany (11.74 ± 15.1 h). Flat running and cycling courses were associated with faster overall race times. Three of the predictive models identified the 'country' and 'age group' variables as the most important predictors. Environmental characteristics showed the lowest influence regarding the other variables. The origin of the athlete was the most predictive variable whereas environmental characteristics showed the lowest influence. Flat cycling and flat running courses were associated with faster overall race times. The fastest overall race times were achieved mainly in European races such as Ironman Copenhagen, Ironman Hawaii, Ironman Barcelona, Ironman Florianópolis, Ironman Frankfurt and Ironman Kalmar. The fastest triathletes originated from European countries such as Belgium, Denmark, Switzerland, Austria, Finland, and Germany.

Cycling is the most important predictive split discipline in professional Ironman® 70.3 triathletes.

Introduction: Our study examined 16,611 records of professional triathletes from 163 Ironman® 70.3 races across 97 countries (2004-2020). The aim was to identify the most predictive discipline-swim, bike, or run-for overall race time. Methods: We used correlation matrices to compare the dependent variable "finish time" with independent variables "swim time," "bike time," and "run time." This analysis was conducted separately for male and female athletes. Additionally, univariate and multiple linear regression models assessed the strength of these associations. Results: The results indicated that "bike time" had the strongest correlation with finish time (0.85), followed by "run time" (0.75 for females, 0.82 for males) and "swim time" (0.46 for females, 0.63 for males). Regression models confirmed "bike time" as the strongest predictor of overall race time (R² = 0.8), with "run time" and "swim time" being less predictive. Discussion: The study concludes that in Ironman 70.3 races, "bike time" is the most significant predictor of overall race performance for both sexes, suggesting a focus on cycling in training and competition strategies. It also highlights a smaller performance gap between genders in swimming than in cycling or running.

Origin and age group of the fastest amateur triathletes competing in 'Ironman Hawaii' between 2003 and 2019.

Little is known about the prevalent nationalities among the best-placed athletes participating in "Ironman Hawaii." Moreover, the age at which athletes achieve their best performances remains unclear. The present study aimed to compare the prevalent nationalities among the athletes, their respective placement among the top five, and the performance difference between the different age groups in 'Ironman Hawaii' from 2003 to 2019. A total of 30 354 amateur triathletes were selected from the Obsessed Triathlete (OBSTRI) website. A "TOP 5" division filter was applied for further analysis, resulting in 1 851 athletes being included in this study. Among the male runners, Americans participated the most in Ironman events (39%), followed by Germans (10%). Among female runners, Americans participated the most (54%), followed by Australian runners (8%). Male Americans also featured most among the top five (30%), followed by Germans (16%). Female Americans were the most prevalent among the top five (47%), followed by Australian Americans (10%). There were no significant performance differences (p â€‹> â€‹0.05) between the 25-29 and 40-44 age groups for either sex. The 45-49 age group presented significantly worse performance than the 35-39 age group for both sexes (p â€‹< â€‹0.001). North Americans were the most performant and frequent participants in "Ironman Hawaii." The expected performance decline due to aging was observed after 45 years in both sexes.