Beat Knechtle

Examining attention- deficit/ hyperactivity disorder in endurance and ultra-endurance runners

Background: Attention-deficit hyperactivity disorder (ADHD) is a multifactorial and complex neurodevelopmental disorder. Prevalence of ADHD in the general adult population is around 3.1 %, with little data available in athlete population suggesting rates of between 7 %-8 %. No data are available for endurance and ultra-endurance runners. Methods: Cross-sectional survey study in endurance (≥21.1 km to 42.2 km) and ultra-endurance runners (≥42.2 km), using the Adult Attention Deficit/Hyperactivity Disorder Self-Report Scale (ASRS-5) for screening for ADHD and assessing associated risk factors and sex differences using statistical and machine learning (ML) techniques. Results: A total of 601 runners participated (female n = 222; male n = 379; mean age 42.8 ± 10.1 years). Overall, 9.7 % of runners returned screening results above the cut off score from the ASRS-5 for ADHD, particularly half-marathon runners (14.8 %; n.s.) compared to marathon (8.0 %) and ultramarathon runners (8.7 %). No significant sex differences (female 10.8 % versus men 9.0 %) or differences in performance levels (elite (0.0 %) versus non-elite (10.1 %) runners) were observed. Age was the only statistically significant associated factor (p = 0.03), particularly in younger runners (under the age of 40 years). Conclusion: This study provides novel essential screening data on ADHD among endurance and ultra-endurance runners. The screening rates for ADHD traits exceed those found in previous studies with elite athletes and the general population. Clinical evaluation, using standard clinical criteria to verify the responses for a definitive diagnosis of ADHD is recommended, as well as increasing awareness of ADHD, education, support services and targeted interventions. Sports organizations, health professionals, and policymakers should implement systematic screening and education programs to address these concerns.

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The Norseman Xtreme Triathlon: A narrative review of current scientific evidence on performance, physiology, and health risks

Background The ‘Norseman Xtreme Triathlon’, held annually in Norway, is considered one of the world’s most challenging triathlons, surpassing the traditional IRONMAN®-distance in terms of difficulty. This narrative review aims to summarize the current scientific evidence to support athletes and coaches in preparation for this event. Methods We conducted a narrative review to summarize the current scientific literature on the ‘Norseman Xtreme Triathlon’. A structured search was conducted in two major databases—PubMed and Scopus—using free-text terms related to ‘Norseman Xtreme Triathlon’. The search included articles published up to the end of November 2025, without language restrictions. After removing duplicates and unrelated articles based on title and abstract screening, 16 relevant publications were included for analysis. Results Over the years, the number of female and male finishers increased, the men-to-women ratio decreased, and both split and overall race times decreased. Most athletes competing in the ‘Norseman Xtreme Triathlon’ came from Norway, and Norwegian athletes achieved the most podiums. The race affects different organ systems and biomarkers, with increased values of WBC, CK, NT-proBNP, CRP and AST returning to pre-race levels within hours or days. Due to the cold environment, athletes appeared to be at risk of developing hypothermia and swimming-induced pulmonary edema (SIPE) during swimming and both exercise-induced bronchoconstriction (EIB) and exercise-induced arterial hypoxemia (EIAH) after the race. Conclusions Particular care is needed in preparing for the cold water and general cold environment during cycling and running. The specific nutritional demands, the aspects of pre-race preparation (e.g. training, experience), post-race recovery trajectories, hormonal profiles, or psychological responses of the ‘Norseman Xtreme Triathlon’ remain underexplored and represent an important area for future research.

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Pacing of the First and Only Female Finisher in the World's Longest Triathlon: The 2024 Triple Deca Ultra Triathlon

Pacing in triathlon has been analyzed for distances up to 60 long-distance triathlons in 60 days in men. However, no study has examined pacing in a female ultra-endurance triathlete in a multi-day triathlon exceeding 10 days. Thus, this case study analyzes the pacing of the first and only woman to complete 30 long-distance triathlons in 30 days. Lap times for swimming, cycling, and running, including transitions, were collected from race results. The athlete tracked each discipline daily using a Fenix 7 Sapphire Solar, recording average and maximum heart rates and energy expenditure. The coefficient of variation and second-order polynomial regression were calculated for average pace, split, and total times. Repeated measures ANOVA tested interactions in pace performance across 10-day phases and intra-discipline daily pacing variations. Multivariate regression examined physiological parameters’ impact on pacing. The female triathlete maintained a relatively even pacing strategy throughout the race, with a decrease in cycling speed and an increase in running speed. Cycling showed the strongest and significant correlation with total race time (r=0.810; p<0.001), while running (r=0.347; p=0.119) and swimming (r=-0.312; p=0.165) displayed non-significant associations. The pace varied within the disciplines, with cycling becoming slower and running faster in the last quarter of the race. Energy expenditure, maximum and average heart rate were significant predictors for cycling (R2=0.538; p<0.001), while only average heart rate was the best predictor for running performance (R2=0.450; p<0.001). Tactical considerations most likely influenced pacing, particularly in cycling and running. Future research should further explore pacing strategies in ultra-endurance events.

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