Background: Objective of this study was to get more insight in hematology, biochemistry, and endocrinology of ultra-endurance exercise, to improve knowledge in this field, supplementation, and medical care of affected athletes.
Methods: A large body of individual hematological, biochemical, and endocrinological parameters was analyzed in the blood taken from ultra-athletes before and after completing the 1993 Colmar ultra triathlon covering 7.5 km swimming, 360 km cycling, and approximately 85 km running.
Participants: Nine experienced ultra-athletes participated in the study. A follow-up was not possible since the athletes left Colmar within 24 hrs after the contest.
Results: The athletes finished the ultra-contest at rankings 4, 5, 7, 8, 9, 11, 18, 22, 23 in a total time between 23:38:53 and 27:54:30 hr:min:sec. Their final body mass (68.6 +/- 1 kg) was significantly lower than at baseline (71.9 +/- 4.2 kg). Non of the athletes made use of medical care. Data after this contest reflect mild hyponatremia, intravascular hemolysis, increased triglyceride turnover, acute-phase reaction, hyperaldosteronemia 2061 +/- 1013 pmol.L-1), hypercortisolemia 971 +/- 486 nmol.L-1), hyper-growth-hormonemia (median 6.8 ng.ml-1), hypoinsulinemia, hypo-free-testosteronemia (42 +/- 17 pmol.L-1), protein catabolism, depressed testicular function, oliguria, and muscle cell leakage.
Conclusions: In our opinion, data presented do not reflect any acute health risks in healthy athletes who are well prepared and carefully supplied during such a contest.