The primary purpose of this investigation was to determine the effects of participation in a 3-day multistage ultraendurance triathlon (stage 1 = 10 km swim, 144.8 km bike; stage 2 = 275.4 km bike; stage 3 = 84.4 km run) on body mass and composition, hydration status, hormones, muscle damage, and blood glucose.
Eighteen triathletes (mean ± SD; age 41 ± 7.5 years; height 175 ± 9 cm; weight 73.5 ± 9.8 kg; male n = 14, female n = 4) were assessed before and after each stage of the race. Body mass and composition were measured via bioelectrical impedance, hydration status via urine specific gravity, hormones and muscle damage via venous blood draw, and blood glucose via fingerstick.
Following the race, significant changes included reductions in body mass (qualified effect size: trivial), fat mass (moderate), and percent body fat (small); increases in percent total body water (moderate) and urine specific gravity (large); and unchanged absolute total body water and fat-free mass. There were also extremely large increases in creatine kinase, C-reactive protein, aldosterone and cortisol combined with reductions in testosterone (small) and the testosterone:cortisol ratio (moderate). There were associations between post-race aldosterone and total body water (r = −0.504) and changes in cortisol and fat-free mass (r = −0.536). Finally, blood glucose increased in a stepwise manner prior to each stage.
Participation in Ultraman Florida leads to fluid retention and dramatic alterations in body composition, muscle health, hormones, and metabolism.
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Free fatty acid
Total body water
Testosterone to cortisol ratio
Urine specific gravity
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We would like to thank all of the athletes that participated in the study and the race directors for permitting us to collect data. Additionally, we thank Fernanda De Carvalho Silva Vargas and Brittany Allman for assistance with the analysis of blood samples. Finally, thanks to Chuck Kemeny for introducing us to the race and facilitating data collection. This study was funded by the Institute of Sports Sciences and Medicine at Florida State University.
Conflict of interest
The authors declare no conflicts of interest.
This work was supported by the Florida State University Institute of Sports Sciences and Medicine.
Communicated by Michael Lindinger.
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Baur, D.A., Bach, C.W., Hyder, W.J. et al. Fluid retention, muscle damage, and altered body composition at the Ultraman triathlon. Eur J Appl Physiol 116, 447–458 (2016). https://doi.org/10.1007/s00421-015-3291-9
- Creatine kinase
- Insulin resistance
- Fat mass
- Urine specific gravity