Performance, physiology, and determinants of success in IRONMAN® 70.3: A systematic review

IRONMAN® 70.3 events represent a rapidly expanding endurance discipline characterized by distinct physiological demands, performance determinants, and race-specific risk profiles. Despite their global popularity, no systematic review has synthesized evidence exclusively focused on this distance. To consolidate current knowledge on performance predictors, physiological responses, training characteristics, nutritional strategies, environmental influences, and medical considerations in IRONMAN® 70.3 triathletes, and to identify gaps requiring further investigation. A systematic search of PubMed, Scopus, SciELO, EBSCO and Google Scholar was conducted up to 25th November 2025. Search terms were developed according to PRISMA guidelines and included variations of ‘Ironman 70.3’, ‘half triathlon’ and ‘middle-distance triathlon’. Eligible studies reporting physiological, anthropometric, nutritional, environmental, medical, or performance-related outcomes specific to IRONMAN® 70.3. Risk of bias was assessed using the Newcastle–Ottawa Scale, the Cochrane RoB tool, and the NIH Quality Assessment Tool, according to study design. A total of 86 studies were included, predominantly observational in design, with sample sizes ranging from 1 to 852,721 participants, mostly trained male triathletes aged 25–39 years. Participation has increased across age groups, with pronounced growth among female and masters triathletes. Peak performance in professional male triathletes is reached at approximately age 28, and in female triathletes at age 32. Across large datasets, cycling appeared to be the strongest predictor of overall race time, accounting for the largest proportion of performance variance. Physiologically, competition was associated with transient reductions in immune function, reversible muscle damage, and shifts in hydration and electrolyte balance, while higher intracellular water and efficient fat oxidation were associated with better outcomes. Evidence specific to IRONMAN® 70.3 is limited by small sample sizes, heterogeneous designs, male-dominated cohorts, and insufficient sex-specific analyses. Future research should distinguish recreational from elite triathletes, incorporate balanced sex representation, and apply standardized physiological and environmental monitoring to refine targeted recommendations for performance, health, and safety.

Sex differences in marathon pacing: analysis of 873,000 Berlin marathon runners reveals men are twice as likely to “hit the wall”

To determine whether sex differences in marathon pacing strategies and susceptibility to catastrophic deceleration (“hitting the wall”) persist in a massive, high-performance dataset, and to quantify this risk across different performance levels. We analyzed 873,334 finishers from the Berlin Marathon (1999–2025). Pacing stability was quantified using the percentage slowdown in the second half relative to the first. “Hitting the wall” was operationally defined as a deceleration of ≥ 20%. A stratified analysis was performed to compare risks between sexes across five performance categories (Competitive to Casual). Multivariable logistic regression adjusted for age and performance category, sensitivity analyses (deduplicated subset; alternative thresholds), and fine-grained pacing metrics from 5 km splits were also conducted. Male runners exhibited significantly greater mean deceleration (10.73% ± 11.41%) compared with female runners (8.34% ± 8.91%, p < 0.001). The prevalence of “hitting the wall” was nearly double in men (17.63%) compared with women (9.66%), corresponding to a crude Odds Ratio of 2.00 (95% CI 1.97 to 2.03); after adjustment for age and performance category, the disparity strengthened (adjusted OR = 3.88, 95% CI 3.81 to 3.94). The risk disparity widened among the fastest runners: in the Competitive (< 3 h) category, male runners were approximately six times more likely to experience catastrophic deceleration than their female counterparts (1.42% vs 0.23%). The gap was stable across the 27-year archive (Mann–Kendall τ = 0.14, p = 0.33). Despite faster finish times, men demonstrate significantly less stable pacing strategies and a twofold higher crude risk of catastrophic deceleration compared with women, with the disparity most pronounced among the fastest runners. These findings are consistent with the hypothesis that behavioral and strategic factors contribute alongside physiological determinants to sex differences in marathon outcomes, and provide a quantitative basis for further investigation of the underlying mechanisms. Sex differences in marathon pacing: analysis of 873,000 Berlin marathon runners reveals men are twice as likely to “hit the wall” | Scientific Reports

Sleep quality and psychological interactions in endurance and ultra-endurance trail runners: A prospective cross-sectional study

Endurance and ultra-endurance running impose substantial physical and psychological demands, leading athletes to experience intense emotional states before, during, and after competitions. Accordingly, there is a paucity of evidence comparing mood profiles between endurance and ultra-endurance runners competing in trail and mountain events. The aim of this study was to characterize the mood profile of endurance and ultra-endurance runners participating in La Misión Brasil 2024 and to analyze its relationship with sleep quality. This prospective cross-sectional study included 193 runners, divided into an endurance group (n = 118; men = 75; women = 43) and an ultra-endurance group (n = 75; men = 60; women = 15), who participated in the same competition according to the proposed distances. La Misión Brasil is a trail running event with race distances ranging from 25 to 80 km and substantial elevation gain. One week prior to the competition, participants completed questionnaires assessing mood state, anxiety, psychological health, and sleep quality. Comparisons between groups (endurance group vs. ultra-endurance group) and sexes were performed using independent t-tests, Mann–Whitney tests, and generalized linear models, whereas associations were examined using Spearman’s correlation. The results indicated higher vigor levels in the ultra-endurance group (p = 0.020) and greater overall fatigue in the endurance group (p = 0.027). Regarding sex differences, men exhibited higher vigor (p = 0.004), whereas women presented higher total mood disturbance and anxiety scores (trait anxiety and state anxiety; p < 0.05). Correlational analyses revealed that poorer sleep quality scores were moderately associated with higher total mood disturbance (r2 = 0.45) and anxiety levels (trait anxiety: r2 = 0.47; state anxiety: r2 = 0.48). Additionally, strong correlations were observed between negative mood states, total mood disturbance, and anxiety (r2 > 0.50). Overall, endurance and ultra-endurance runners demonstrated a favorable mood profile; however, the psychological demands of these modalities are associated with relevant interactions between sleep, mood, and anxiety.

Why men lose pace more often than women in the marathon

Men more often experience a drop in performance over long distances than women. This is often due to how they start. One of Switzerland’s biggest endurance events is currently taking place in Thun: the Ironman Switzerland. Around 2,300 athletes are fighting for every minute over 3.8 kilometres of swimming, 180 kilometres of cycling and a full marathon. Fittingly, there are new findings from the University of Zurich on long-distance running, which they have now published in the journal “Scientific Reports.”

Performance patterns and records in the world aquatics masters championships: Where do the most frequently represented nations among the top-ten masters swimmers come from?

Masters Swimming is a rapidly expanding sector of competitive aquatic sport and provides structured opportunities for adults to maintain long-term engagement in high-level swimming. Despite extensive global participation, limited evidence exists regarding the national origins of the most frequent Masters swimmers among the top-ten performers across all strokes, distances, and age groups. Previous research has focused primarily on isolated disciplines or open-water events. This study aimed to investigate participation and performance patterns of Masters swimmers competing at the World Masters and World Aquatics Championships from 1986 to 2024, with a specific focus on national patterns among top performers. A total of 204,005 long-course (50 m) swimming performance entries (94,312 women and 109,693 men) from 1986 to 2024 were extracted from the official World Aquatics archive and analyzed. The unit of analysis was the annual top-ten entries for each stroke, distance, sex, and age group, with each result treated as an independent performance record. Statistical differences between nationalities were assessed using Kruskal-Wallis tests with Bonferroni post-hoc adjustments. Descriptive data were presented using mean, standard deviation, and confidence intervals. Success was operationally defined as the frequency of a nation’s appearances in the annual top-ten fastest times for each stroke, distance, and sex. For descriptive purposes, nationalities were grouped into six categories: the top-five nationalities with the most appearances in the top-ten fastest times regarding the different swimming strokes and sex separately by distances and for each competition year, as well as one group of all other nationalities. Among women, German swimmers were the most numerous in the top-ten for breaststroke, butterfly, and 50 m backstroke. Among men, however, U.S. swimmers were the most frequently represented across almost all distances and strokes, except for the successes of Brazilian athletes in the 50 m backstroke and Russian swimmers in the 50 m breaststroke. Across all years and disciplines, the most recurrent top-ten Masters swimmers came from the USA, Germany, Great Britain, Russia, Italy, and Brazil (“Big Six”). Performance differences between nationalities were significant across multiple events, with notable strengths among Russian swimmers in breaststroke and freestyle sprint events. The United States demonstrated the broadest and most consistent numerical superiority in Masters swimming performance over the 38-year period, by fielding the most frequent athletes among the top-ten performers, particularly among men. German women displayed exceptional success in breaststroke and butterfly, accounting for the majority of the athletes in the top-ten. These findings highlight persistent geographic patterns in Masters swimming excellence and may guide future research on environmental, sociocultural, training, and demographic factors contributing to national performance patterns.

Physiological and performance characteristics in the Spartathlon: A narrative review of scientific findings

The Spartathlon is a 246-km ultra-endurance running race, considered as one of the most iconic and physically demanding ultra-marathons in the world. In this narrative review, we aimed to synthesize the available current evidence on the physiological responses, performance trends, and health implications associated with participation in the Spartathlon. A systematic literature search was conducted to identify high-quality scientific studies on the Spartathlon. The databases Cochrane, EMBASE, PubMed, Scopus, and Web of Science were used to retrieve articles published up to December 2025. We found a total of 33 publications in Web of Science, 25 in Embase, 24 in Scopus, 23 in PubMed, and 1 in Cochrane. After removing duplicates and applying the eligibility criteria, a final selection of studies was included for analysis in this narrative review. The findings on the cardiac system showed reversible changes in echocardiography and cardiac biomarkers. Running the Spartathlon leads to specific effects on the locomotor system, such as an increase in peak pressure in the forefoot area, an increase in biochemical markers of muscle damage and changes in bone metabolism markers. Notably, the use of oral proton pump inhibitors was associated with a lower incidence of gastrointestinal bleeding. The Spartathlon also showed the highest prevalence of exercise-associated hyponatremia (EAH) of up to 65% as reported in the literature on ultra-marathon running. In addition, running Spartathlon leads to an inflammatory response and an increase in oxidative stress. Participation in the Spartathlon leads to several well-documented post-race physiological alterations, particularly affecting the cardiovascular and musculoskeletal systems. Overall, the Spartathlon represents a unique model for studying human physiological resilience and adaptation under extreme conditions.

10 Marathons in 10 Days in Bad Blumau

From June 26 to July 5, 2026, the 9th edition of “10 Marathons in 10 Days” took place in Bad Blumau, Styria, Austria. Participants had to complete a total distance of 422 km in temperatures reaching nearly 40 degrees.

A medal was awarded for each marathon, and at the end, an additional medal was given to those who completed all 10 marathons.

What 50,000 Runners And 76 Studies Teach Us About Racing The NYC Marathon Smarter

A new systematic review¹ of the New York City Marathon reveals what the data says about pacing, injuries, aging, and performance — and what every runner can take from it. The New York City Marathon is a giant endurance laboratory. More than 50,000 runners. Five boroughs. Bridges, wind, crowding, long pre-race logistics, uneven pacing demands, variable weather, and every kind of runner from world-class professionals to first-time marathoners. A new systematic review ‌compiled the scientific literature on the NYC Marathon, including 76 publications reporting findings on participation, performance, aging, nationality, injuries, environment, pacing, medical outcomes, shoes, and other race-specific features.

Kenya’s marathon magic fades after age 40, study finds

Sabastian Sawe’s recent sub-two-hour marathon run was another reminder that Kenya still rules long-distance running. But a major new global study suggests that this picture is incomplete. Kenya’s grip on the marathon appears strongest just in youth, then fades sharply as runners grow older. The Star spoke to researchers who analysed records of more than one million marathon runners over five years. They found that Kenyans and Ethiopians lead the world only between ages 20 and 39. Then the tables turn. After age 40, marathon runners from the United States, Japan, Germany and Switzerland dominate the road.