Effect of a multistage ultraendurance triathlon on aldosterone, vasopressin, extracellular water and urine electrolytes.

Prolonged endurance exercise over several days induces increase in extracellular water (ECW). We aimed to investigate an association between the increase in ECW and the change in aldosterone and vasopressin in a multistage ultraendurance triathlon, the 'World Challenge Deca Iron Triathlon' with 10 Ironman triathlons within 10 days. Before and after each Ironman, body mass, ECW, urinary [Na(+)], urinary [K(+)], urinary specific gravity, urinary osmolality and aldosterone and vasopressin in plasma were measured. The 11 finishers completed the total distance of 38 km swimming, 1800 km cycling and 422 km running within 145.5 (18.8) hours and 25 (22) minutes. ECW increased by 0.9 (1.1) L from 14.6 (1.5) L prerace to 15.5 (1.9) L postrace (P < 0.0001). Aldosterone increased from 70.8 (104.5) pg/mL to 102.6 (104.6) pg/mL (P = 0.033); vasopressin remained unchanged. The increase in ECW was related neither to postrace aldosterone nor to postrace vasopressin. In conclusion, ECW and aldosterone increased after this multistage ultraendurance triathlon, but vasopressin did not. The increase in ECW and the increase in aldosterone were not associated.

[The effect of a multi-stage ultra-endurance triathlon over ten times an iron-man-triathlon on fat mass and skeletal muscle mass--the world challenge deca iron 2006]. / Der Einfluss von zehn aufein- ander folgenden Langdistanz- TriathLons auf Körperfett und Muskelmasse--World Challenge Deca Iron 2006.

The present study investigated the change of body composition in 8 ultra-endurance triathletes during a multi-stage ultra-endurance triathlon, where athletes had to perform one Ironman distance over 3.8 km swimming, 180 km cycling and 42.2 km running per day for 10 consecutive days. In the only 8 male successful finishers, body mass, skin fold thicknesses and circumferences of extremities were measured pre and post race in order to calculate skeletal muscle mass, percent body fat and fat mass. Bioelectrical impedance analysis was performed at the same time to determine lean body mass, percent body fat and total body water. Body mass did not change (p > 0.05), whereas skeletal muscle mass statistically significantly decreased by 1.1 kg (p < 0.05) and fat mass significantly decreased by 0.9 kg (p < 0.05).

Effect of a multistage ultra-endurance triathlon on body composition: World Challenge Deca Iron Triathlon 2006.

OBJECTIVE: To investigate the effect of a multistage ultra-endurance triathlon on body composition in ultra-triathletes. DESIGN: Descriptive field study. SETTING: The "World Challenge Deca Iron Triathlon 2006" in Monterrey, Mexico, in which every day for 10 consecutive days athletes had to perform the distance of one Ironman triathlon. SUBJECTS: Eight male ultra-endurance athletes (mean (SD) age 40.6 (10.7) years, weight 76.4 (8.4) kg, height 175 (4) cm and body mass index (BMI) 24.7 (2.2) kg/m2). INTERVENTIONS: None. MAIN OUTCOME MEASUREMENTS: Determination of body mass, protein mass, body fat, per cent body fat, mineral mass, total body water, intracellular water, extracellular water and lean body mass with a direct segmental multifrequency bioelectrical impedance method before the race and after each stage in order to show changes in body composition. RESULTS: A statistically significant decrease of body mass (-2.4 kg, p = 0.014), body fat (-5 kg, p = 0.0078) and per cent body fat (-6.4%, p = 0.0078) occurred at the end of the first day compared to values taken in the pre-race period. In contrast, at the same time, a statistically significant increase of protein mass (+0.7 kg, p = 0.035), mineral mass (+0.2 kg, p = 0.04), total body water (+1.8 litres, p = 0.042), intracellular water (+1.6 litres, p = 0.034) and lean body mass (+2.6 kg, p = 0.023) was shown. After the first day until the end of the challenge, body fat (-3 kg, p>0.05) and per cent body fat (-3.9%, p>0.05) showed a statistically significant decrease, whereas the other parameters showed no changes. CONCLUSIONS: Athletes taking part in a multistage ultra-endurance triathlon over 10 Ironman triathlon distances in 10 consecutive days lost 3 kg of body fat; skeletal muscle mass, mineral mass and body water were unchanged.

Effects of a Deca Iron Triathlon on body composition: a case study.

We investigated energy balance and change of body composition in one athlete in a multistage triathlon, the World Challenge Deca Iron Triathlon 2006, where athletes had to perform one Ironman triathlon of 3.8 km swimming, 180 km cycling and 42.195 km running per day for ten consecutive days. In one well-experienced male ultra-endurance triathlete, we measured body mass, skinfold thicknesses and perimeters of extremities, in order to calculate skeletal muscle mass, fat mass and percentage of body fat. Energy intake was measured by analysis of nutrition, and energy expenditure was calculated using a portable heart rate monitor. This was performed to quantify energy deficit. In addition, bio-impedance measurements were performed to determine fluid metabolism. The athlete finished the race in 128 hours, 22 minutes and 42 seconds in 3rd position. Body mass decreased by 1 kilogram, skeletal muscle mass decreased by 0.9 kilograms and calculated fat mass decreased by 0.8 kilograms. Total body water increased by 2.8 liters. Total energy expenditure for the Deca Iron was 89,112 kilocalories and a total energy deficit of 11,480 kilocalories resulted. We presume that energy deficit was covered by consumption of adipose subcutaneous tissue as well as skeletal muscle mass; the degradation of muscle mass seems to lead to hypoproteinemic edemas.