Low prevalence of exercise-associated hyponatremia in male 100km ultra-marathon runners in Switzerland

We investigated the prevalence of exercise-associated hyponatremia (EAH) in 145 male ultra-marathoners at the ‘100-km ultra-run' in Biel, Switzerland. Changes in body mass, urinary specific gravity, haemoglobin, haematocrit, plasma [Na+], and plasma volume were determined. Seven runners (4.8%) developed asymptomatic EAH. Body mass, haematocrit and haemoglobin decreased, plasma [Na+] remained unchanged and plasma volume increased. Δ body mass correlated with both post race plasma [Na+] and Δ plasma [Na+]. Δ plasma volume was associated with post race plasma [Na+]. The athletes consumed 0.65 (0.30) L/h; fluid intake correlated significantly and negatively (r=−0.50, p<0.0001) to race time. Fluid intake was neither associated with post race plasma [Na+] nor with Δ plasma [Na+], but was related to Δ body mass. To conclude, the prevalence of EAH was low at ~5% in these male 100km ultra-marathoners. EAH was asymptomatic and would not have been detected without the measurement of plasma [Na+

Skin-fold thickness and race performance in male mountain ultra-marathoners

Recent studies showed in high level runners both an association between selected skin-fold thicknesses at the lower limb and running performance and between thickness of skin-fold and training. We investigated the association of skin-fold thicknesses with total race time in 25 male mountain ultra-marathoners with 44.5 (7.0) years, 73.0 (7.8) kg body mass, 1.78 (0.07) m body height and a BMI of 22.9 (1.8) kg/m2 in a 7-day mountain ultra-marathon over 350 km with 11,000 m of altitude. The relationship of skin-fold thickness and both intensity and volume during training with total race time as the dependent variable was investigated using multiple linear regression analysis. A significant association of the calf skin-fold with total race time was found (r2 = 0.19, p < 0.05). No relationship between skin-fold thickness and both average running speed and volume in training could be demonstrated. We concluded that the calf skin-fold showed a small to moderate association with total race time, however, the thickness of calf skin-fold was not related to training parameters

No case of exercise-associated hyponatraemia in top male ultra-endurance cyclists: the ‘Swiss Cycling Marathon'

The prevalence of exercise-associated hyponatraemia (EAH) has been investigated in endurance athletes such as runners and Ironman triathletes, but not in ultra-endurance road cyclists. We assessed fluid intake and changes in body mass, urine specific gravity and plasma sodium concentration ([Na+]) in 65 ultra-endurance road cyclists in a 720-km ultra-cycling marathon, the ‘Swiss Cycling Marathon'. The cyclists lost 1.5 (1.7)% body mass (P<0.01). No athlete developed EAH. Fluid intake was associated with the change in plasma [Na+] (r=−0.32, P<0.05) and the change in body mass (r=−0.30, P<0.05). The change in plasma [Na+] was related to post-race plasma [Na+] (r=0.63, P<0.0001). To conclude, ad libitum fluid intake in ultra-endurance cyclists in a single-stage ultra-endurance road cycling race showed no case of EAH. Future studies regarding drinking behaviour in different ultra-endurance disciplines might give insights into why the prevalence of EAH is different in the different discipline

Age of peak performance in 50-km ultramarathoners - is it older than in marathoners?

Purpose: Despite the increasing popularity of 50-km ultramarathons during the last few years, only limited information is available regarding the trends in its performance and participation. The aim of the present study was to examine the age of peak running performance in female and male 50-km ultramarathoners using second-order nonlinear regression analyses. Methods: Data from 494,414 runners (124,045 women and 370,369 men) who finished a 50-km ultramarathon between 1975 to 2016 were analyzed. Results: When the top ten finishers in 1-year age-groups were analyzed, the age of peak running speed was 41 years in both women and men. When the fastest finishers in 1-year age-group intervals were analyzed, the age of peak running speed was 40 years in women and 39 years in men. Conclusion: In summary, the age of peak running speed in 50-km ultramarathoners is older than what has been reported by previous studies for marathons. Women seem to achieve the best race time in a 50-km ultramarathon later in life compared with men. These findings are of great practical value for coaches and fitness trainers when setting performance goals for 50-km ultramarathon runners

Atrophy of the brachialis muscle after a displaced clavicle fracture in an Ironman triathlete: case report

Clavicle fractures are frequent injuries in athletes and midshaft clavicle fractures in particular are well-known injuries in Ironman triathletes. In 2000, Auzou et al. described the mechanism leading to an isolated truncular paralysis of the musculocutaneous nerve after a shoulder trauma. It is well-known that nerve palsies can lead to an atrophy of the associated muscle if they persist for months or even longer. In this case report we describe a new case of an Ironman triathlete suffering from a persistent isolated atrophy of the brachialis muscle. The atrophy occurred following a displaced midshaft clavicle fracture acquiring while falling off his bike after hitting a duck during a competition

Predictors of half-marathon performance in male recreational athletes

Few research has been conducted on predictors of recreational runners' performance, especially in half-marathon running. The purpose of our study was (a) to investigate the relationship of half-marathon race time with training, anthropometry and physiological characteristics, and (b) to develop a formula to predict half-marathon race time in male recreational runners. Recreational runners (n=134, age 44.2±8.7 years; half-marathon race time 104.6±16.2 min) underwent a physical fitness battery consisting of anthropometric and physiological tests. The participants were classified into five performance groups (fast, 73-92 min; above average, 93-99 min; average 100-107 min; below average, 108-117 min; slow group, 118-160 min). A prediction equation was developed in an experimental group (EXP, n=67), validated in a control group (CON, n=67) and prediction bias was estimated with 95 % confidence intervals (CI). Performance groups differed in half-marathon race time, training days, training distance, age, weight, (body mass index) BMI, body fat (BF) and maximum oxygen uptake (VO$_{2}$max) (p≤0.001, η$^{2}$≥0.132), where faster groups had better scores than the slower groups. Half-marathon race time correlated with physiological, anthropometric and training characteristics, with the faster the runner, the better the score in these characteristics (e.g., VO$_{2}$max, r=0.59; BMI, r=-0.55; weekly running distance, r=-0.53, p<0.001). Race time in EXP might be calculated (R$^{2}$=0.63, standard error of the estimate=9.9) using the equation 'Race time (min)=80.056+2.498×BMI-0.594×VO$_{2}$max-0.191×weekly training distance in km'. Validating this formula in CON, no bias was shown (difference between observed and predicted value 2.3±12.8 min, 95 % CI -0.9, 5.4, p=0.153). Half-marathon race time was related to and could be predicted by BMI, VO$_{2}$max and weekly running distance. Based on these relationships, a prediction formula for race time was developed providing a practical tool for recreational runners and professionals working with them

Higher prevalence of exercise-associated hyponatremia in female than in male open-water ultra-endurance swimmers: the ‘Marathon-Swim' in Lake Zurich

We investigated the prevalence of exercise-associated hyponatremia (EAH) in 25 male and 11 female open-water ultra-endurance swimmers participating in the ‘Marathon-Swim' in Lake Zurich, Switzerland, covering a distance of 26.4km. Changes in body mass, fat mass, skeletal muscle mass, total body water, urine specific gravity, plasma sodium concentration [Na+] and haematocrit were determined. Two males (8%) and four females (36%) developed EAH where one female was symptomatic with plasma sodium [Na+] of 127mmol/L. Body mass and plasma [Na+] decreased (p<0.05). The changes in body mass correlated in both male and female swimmers to post-race plasma [Na+] (r=−0.67, p=0.0002 and r=−0.80, p=0.0034, respectively) and changes in plasma [Na+] (r=−0.68, p=0.0002 and r=−0.79, p=0.0039, respectively). Fluid intake was neither associated with changes in body mass, post-race plasma [Na+] or the change in plasma [Na+]. Sodium intake showed no association with either the changes in plasma [Na+] or post-race plasma [Na+]. We concluded that the prevalence of EAH was greater in female than in male open-water ultra-endurance swimmer

Sports and Health, Second Edition

The International Journal of Environmental Research and Public Health (IJERPH) has increased its publications of scientific papers related to exercise; a search of Pubmed (on 22 June 2022) using IJERPH and exercise as keywords showed 1788 entries for 2021 compared to 80 entries in 2016 [...

Swimming during COVID-19: Operational recommendations and considerations for South African swimming venues

Swimming is one of the most popular recreational activities in South Africa. Since the emergence of the Coronavirus disease 2019 (COVID-19), South Africa imposed one of the strictest lockdown measures to contain and control the spread of the virus. These measures included the closure of gyms, fitness centres and swimming pools across the country. However, as the restrictions begin to ease, it is important to consider how swimming facilities can reopen whilst simultaneously ensuring appropriate measures are in place to reduce COVID-19 infections. Outlined are recommendations and considerations for swimming facilities in South Africa. Currently there is no evidence to suggest that COVID-19 transmission to humans is possible through water, making swimming one of the safer options for physical activity indoors. However, participation is still not without risk and compliance with government mandates and public health officials take precedent over the recommendations outlined in this article

Pacing Strategies in the ‘Athens Classic Marathon’: Physiological and Psychological Aspects

Despite the increased scientific interest in the relationship between pacing and performance in marathon running, little information is available about the association of pacing with physiological and psychological parameters. Therefore, the aim of the present study was to examine the role physical fitness and training characteristics on pacing in the ‘Athens Classic Marathon.’ Finishers in this race in 2017 (women, n = 26, age 40.8 ± 9.4 years; men, n = 130, age 44.1 ± 8.6 years) were analyzed for their pacing during the race, completed the Motivation of Marathon Scale (MOMS) and performed a series of physiological tests. Women and faster recreational runners adopted a more even pacing. A more even pacing was related with a higher aerobic capacity and lower muscle strength in men, but not in women. Men with more even pacing scored higher in psychological coping, self-esteem, life meaning, recognition and competition than their counterparts with less even pacing. Considering the increasing number of participants in marathon races, these findings might help a wide range of professionals (fitness trainers, physiologists, and psychologists) working with runners to optimize the pacing of their athletes