The age-related decline in Olympic distance triathlon performance differs between males and females.

AIM: The aim of this cross-sectional study was to compare the age-related declines in swimming, cycling, and running and overall race times between males and females in an Olympic distance triathlon, the 'Zürich Triathlon' in Switzerland. METHODS: Swimming (1.5 km), cycling (40 km), running (10 km) and overall race times of 7939 total finishers (1666 females and 6273 males) from 2000 to 2010 in the "Zürich Triathlon" were analysed. RESULTS: There was a significant (P<0.001) age effect on performance for both males and females independently of the discipline. No significant difference in the overall race time was observed between 18 and 34 years for both genders. There was an interaction (P<0.001) of age and gender for swimming, cycling and overall race times, but not for running times. The age-related declines in performance were significantly less pronounced for males compared with females for swimming (>50 years), for cycling (>40 years) and for overall race time (>40 years). CONCLUSION: These data suggest that the age and gender interactions in an Olympic distance triathlon performance differ between the three locomotion modes. Further studies investigating training regimes, competition experience or socio-demographic factors are needed to get a better insight in the phenomenon of the gender specific age-related declines in endurance performance.

Male swimmers cross the English Channel faster than female swimmers.

We examined the gender difference in performance of open-water ultra-swimmers crossing the English Channel between 1875 and 2011. A total of 1606 swimmers (1120 males and 486 females) crossed the English Channel within a mean time of 809.6 ± 175.6 min. The overall female swim time of 796.3 ± 188.7 min was not different compared with the overall male swim time of 815.4 ± 169.4 min (P > 0.05). The fastest male swim time ever of 417 min was 6.7% faster than the fastest female swim time ever with 445 min. The gender difference in performance of the top three times ever was 8.9 ± 2.3%. Over the last 36 years, the performance of the annual top three swimmers showed no changes for both females and males. The top three males (564.3 ± 63.8 min) were significantly faster than the top three females (602.1 ± 58.7 min; P < 0.01). The gender difference remained unchanged at 12.5 ± 9.6% over the years. To summarize, the top three male swimmers in the English Channel were ∼12% faster than the females in the last 36 years. It seems unlikely that female open-water ultra-swimmers will overtop males in the near future in the English Channel.

Regulation of electrolyte and fluid metabolism in multi-stage ultra-marathoners.

The purposes of this study were (i) to determine the prevalence of exercise-associated hyponatremia (EAH) in multi-stage ultra-marathoners and (ii) to gain more insight into fluid and electrolyte regulation during a multi-stage race. Body mass, sodium concentration ([Na⁺]), potassium concentration ([K⁺]), creatinine, urea, specific gravity, and osmolality in urine were measured in 25 male ultra-marathoners in the 'Swiss Jura Marathon' 2008 with 11,000 m gain of altitude over 7 stages covering 350 km, before and after each stage. Haemoglobin, haematocrit, creatinine, urea, [Na⁺], [K⁺], and osmolality were measured in plasma before stage 1 and after stages 1, 3, 5, and 7. Two athletes (8%) showed plasma [Na⁺] <135 mmol/l. Body mass, plasma [Na⁺], and plasma [K⁺] remained unchanged (p>0.05). Urine specific gravity (p<0.001) and osmolality in both plasma (p<0.01) and urine (p<0.001) were increased and haematocrit (p<0.0001), haemoglobin (p<0.0001) and plasma albumin were decreased (p<0.001). Plasma volume (p<0.01) and plasma urea (p<0.001) were increased. The K⁺/Na⁺ ratio in urine increased >1.0 after each stage and returned to <1.0 the morning of the next stage (p<0.001). To summarize, more sodium than potassium was excreted during rest. The increased urinary sodium losses during rest are compatible with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) or the cerebral salt-wasting syndrome (CSWS). Further studies are needed to determine the antidiuretic hormone (ADH) and both the atrial natriuretic peptide (ANP) and the brain natriuretic peptide (BNP) during multi-stage races.

Maintained serum sodium in male ultra-marathoners--the role of fluid intake, vasopressin, and aldosterone in fluid and electrolyte regulation.

Exercise-associated hyponatremia (EAH) is a well know electrolyte disorder in endurance athletes. Although fluid overload is the most like etiology, recent studies, however, argued whether EAH is a disorder of vasopressin secretion. The aims of the present study were to investigate (i) the prevalence of EAH in male ultra-marathoners and (ii) whether fluid intake, aldosterone or vasopressin, as measured by copeptin, were associated with post-race serum sodium concentration ([Na+]). In 50 male ultra-marathoners in a 100 km ultra-marathon, serum [Na+], aldosterone, copeptin, serum and urine osmolality, and body mass were measured pre- and post-race. Fluid intake, renal function parameters and urine excretion were measured. No athlete developed EAH. Copeptin and aldosterone increased; a significant correlation was found between the change in copeptin and the change in serum [Na+], no correlation was found between aldosterone and serum [Na+]. Serum [Na+] increased by 1.6%; body mass decreased by 1.9 kg. The change in serum [Na+] and body mass correlated significantly and negatively. The fluid intake of ~ 0.58 l/h was positively related to the change in body mass and negatively to both post-race serum [Na+] and the change in serum [Na+]. We conclude that serum [Na+] was maintained by both the mechanisms of fluid intake and the hormonal regulation of vasopressin.

[Help, I have crooked fingers - or the solution to a series of medical phenomena]. / Hilfe, ich habe krumme Finger - oder die Lösung einer Reihe medizinischer Phänomene.

We describe the case of a 23-year old man, who is himself a student of human medicine and who performed, thanks to his knowledge gained during his studies, a presumptive diagnosis of the Ehlers-Danlos-syndrome on himself. This fact was previously underdiagnosed by several physicians, who were consulted due to the manifestation of symptoms.

A comparison of fat mass and skeletal muscle mass estimation in male ultra-endurance athletes using bioelectrical impedance analysis and different anthropometric methods.

Two hundred and fifty seven male Caucasian ultra-endurance athletes were recruited, pre-race, before different swimming, cycling, running and triathlon races. Fat mass and skeletal muscle mass were estimated using bioelectrical impedance analysis (BIA) and anthropometric methods in order to investigate whether the use of BIA or anthropometry would be useful under field conditions. Total body fat estimated using BIA was significantly high (P < 0.001) compared with anthropometry. When the results between BIA and anthropometry were compared, moderate to low levels of agreement were found. These results were in accordance with the differences found in the Bland-Altman analysis, indicating that the anthropometric equation of Ball et al. had the highest level of agreement (Bias = -3.0 ± 5.8 kg) with BIA, using Stewart et al. (Bias = -6.4 ± 6.3 kg), Faulkner (Bias = -4.7 ± 5.8 kg) and Wilmore-Siri (Bias = -4.8 ± 6.2 kg). The estimation of skeletal muscle mass using BIA was significantly (P < 0.001) above compared with anthropometry. The results of the ICC and Bland-Altman method showed that the anthropometric equation from Lee et al. (Bias = -5.4 ± 5.3 kg) produced the highest level of agreement. The combined method of Janssen et al. between anthropometry and BIA showed a lower level of agreement (Bias = -12.5 ± 5.7 kg). There was a statistically significant difference between the results derived from the equation of Lee et al. and Janssen et al. (P < 0.001). To summarise, the determination of body composition in ultra-endurance athletes using BIA reported significantly high values of fat and skeletal muscle mass when compared with anthropometric equations.