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+

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

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

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

An increased fluid intake leads to feet swelling in 100-km ultra-marathoners - an observational field study

BACKGROUND: An association between fluid intake and changes in volumes of the upper and lower limb has been described in 100-km ultra-marathoners. The purpose of the present study was (i) to investigate the association between fluid intake and a potential development of peripheral oedemas leading to an increase of the feet volume in 100-km ultra-marathoners and (ii) to evaluate a possible association between the changes in plasma sodium concentration ([Na+]) and changes in feet volume. METHODS: In seventy-six 100-km ultra-marathoners, body mass, plasma [Na+], haematocrit and urine specific gravity were determined pre- and post-race. Fluid intake and the changes of volume of the feet were measured where the changes of volume of the feet were estimated using plethysmography. RESULTS: Body mass decreased by 1.8 kg (2.4%) (p 0.05). Plasma volume and urine specific gravity increased (p < 0.0001). Fluid intake was positively related to the change in the volume of the feet (r = 0.54, p < 0.0001) and negatively to post-race plasma [Na+] (r = -0.28, p = 0.0142). Running speed was negatively related to both fluid intake (r = -0.33, p = 0.0036) and the change in feet volume (r = -0.23, p = 0.0236). The change in the volume of the feet was negatively related to the change in plasma [Na+] (r = -0.26, p = 0.0227). The change in body mass was negatively related to both post-race plasma [Na+] (r = -0.28, p = 0.0129) and running speed (r = -0.34, p = 0.0028). CONCLUSIONS: An increase in feet volume after a 100-km ultra-marathon was due to an increased fluid intake

Fluid intake and changes in limb volumes in male ultra-marathoners: does fluid overload lead to peripheral oedema?

An increase in body mass due to oedema has been previously described. The aim of this study was to investigate a potential association between both fluid and electrolyte intake and the formation of peripheral oedemas. Fluid and electrolyte intakes and the changes in limb volumes in 50 male 100-km ultra-marathoners were measured. Pre- and post-race serum sodium concentration ([Na+]), serum aldosterone concentration, serum copeptin concentration, serum and urine osmolality and body mass were determined. Fluid intake, renal function parameters and urinary output, as well as the changes of volume in the extremities, were measured. The changes of volume in the limbs were measured using plethysmography. Serum [Na+] increased by 1.6%; body mass decreased by 1.9kg. Serum copeptin and aldosterone concentrations were increased. The change in serum copeptin concentration and the change in serum [Na+] correlated positively; the change in serum [Na+] and body mass correlated negatively. A mean fluid intake of 0.58L/h was positively related to running speed and negatively to post-race serum [Na+]. Total fluid intake was positively related to the changes in both arm and lower leg volumes. Running speed was positively associated with the changes in arm and lower leg volumes; race time was related to the changes in serum copeptin or aldosterone concentrations. To conclude, fluid intake was related to the changes in limb volumes, where athletes with an increased fluid intake developed an increase in limb volume

Participation and Performance Trends in Triple Iron Ultra-triathlon - a Cross-sectional and Longitudinal Data Analysis

PURPOSE: The aims of the present study were to investigate (i) the changes in participation and performance and (ii) the gender difference in Triple Iron ultra-triathlon (11.4 km swimming, 540 km cycling and 126.6 km running) across years from 1988 to 2011. METHODS: For the cross-sectional data analysis, the association between with overall race times and split times was investigated using simple linear regression analyses and analysis of variance. For the longitudinal data analysis, the changes in race times for the five men and women with the highest number of participations were analysed using simple linear regression analyses. RESULTS: During the studied period, the number of finishers were 824 (71.4%) for men and 80 (78.4%) for women. Participation increased for men (r(2)=0.27, P<0.01) while it remained stable for women (8%). Total race times were 2,146 ± 127.3 min for men and 2,615 ± 327.2 min for women (P<0.001). Total race time decreased for men (r(2)=0.17; P=0.043), while it increased for women (r(2)=0.49; P=0.001) across years. The gender difference in overall race time for winners increased from 10% in 1992 to 42% in 2011 (r(2)=0.63; P<0.001). The longitudinal analysis of the five women and five men with the highest number of participations showed that performance decreased in one female (r(2)=0.45; P=0.01). The four other women as well as all five men showed no change in overall race times across years. CONCLUSIONS: Participation increased and performance improved for male Triple Iron ultra-triathletes while participation remained unchanged and performance decreased for females between 1988 and 2011. The reasons for the increase of the gap between female and male Triple Iron ultra-triathletes need further investigations

No effect of short-term amino acid supplementation on variables related to skeletal muscle damage in 100 km ultra-runners - a randomized controlled trial

Background: The purpose of this study was to investigate the effect of short-term supplementation of amino acids before and during a 100 km ultra-marathon on variables of skeletal muscle damage and muscle soreness. We hypothesized that the supplementation of amino acids before and during an ultra-marathon would lead to a reduction in the variables of skeletal muscle damage, a decrease in muscle soreness and an improved performance. Methods: Twenty-eight experienced male ultra-runners were divided into two groups, one with amino acid supplementation and the other as a control group. The amino acid group was supplemented a total of 52.5 g of an amino acid concentrate before and during the 100 km ultra-marathon. Pre- and post-race, creatine kinase, urea and myoglobin were determined. At the same time, the athletes were asked for subjective feelings of muscle soreness. Results: Race time was not different between the groups when controlled for personal best time in a 100 km ultra-marathon. The increases in creatine kinase, urea and myoglobin were not different in both groups. Subjective feelings of skeletal muscle soreness were not different between the groups. Conclusions: We concluded that short-term supplementation of amino acids before and during a 100 km ultra-marathon had no effect on variables of skeletal muscle damage and muscle soreness

No association of skin-fold thicknesses and training with race performance in male ultra-endurance runners in a 24-hour run

In male high-level long-distance runners over 10,000 m, a positive association between both the front thigh and medial calf skin-fold thickness and running performance has been demonstrated. It is assumed that the thickness of skin-folds of the lower limb is related to training in highly trained runners. We investigated in 22 male ultra-endurance runners in a 24-hour run the relationship between skin-fold thicknesses and race performance. The 22 runners achieved a total of 154 (47) km during the 24 hours, varying from 73.079 km to 231.956 km. No association for both the skin-fold thicknesses and the training variables with race performance could be demonstrated. Furthermore, skin-fold thicknesses showed no relationship with both volume and intensity during training. We must assume that in ultra-endurance runners in a 24-hour run, other variables such as motivation and nutrition must be associated with race outcome

Does a multi-stage ultra-endurance run cause de- or hyper hydration?

We investigated the changes in body mass and parameters of both renal function and fluid metabolism in a case study in a female ultra-endurance runner during the longest multi-stage mountain ultra-marathon in Europe, the ‘Swiss Jura Marathon’ in 2008. The female ultra-runner performed the 7 stages with a total distance of 175 km, a total ascent of 5,000 m, and a total descent of 8,000 m within 23:11 h: min, finishing as second female runner. By the end of the race, body mass decreased by 0.3 kg, fat mass by 1.2 kg and skeletal muscle mass by 0.7 kg. Haemoglobin and haematocrit decreased by 4.5% and 7.5 %, respectively, and plasma volume increased by 10 %. Serum osmolality decreased by 3.3%. Parameters of myocellular damage increased substantially (CK + 630 %, LDH + 178 % and GOT + 181 %). Creatinine continuously increased in plasma (+ 23 %) and urine (+ 47 %). Creatinine clearance (– 18.7 %), glomerular filtration rate (– 19.4 %) and serum albumin (– 10.6 %) decreased. Urinary specific gravity decreased after each stage and was increased before each stage. Urinary osmolality decreased after each stage and was increased before each stage. The average daily fluid intake from stage 1 to stage 7 (during performance and rest) was 4.9 l per day. Total body water increased by 1.2 l by the end of the race. The potassium-to-sodium ratio in urine was increased after each stage. We assume that the increase in total body water was due to an increased activity in the renin-angiotensin-aldosterone-system as evidenced by the change in urinary electrolytes after the stages and an increased activity of vasopressin as evidenced by increase of urinary osmolality before the stages