Endurance Athletes May Suffer Dangerous Metabolic Effects
'Ultraman' competitors experience muscle damage and insulin resistance, researchers find
MONDAY, Dec. 7, 2015 (HealthDay News) -- Participation in the endurance competition known as the Ultraman is associated with dramatic alterations in body composition, muscle health, hormones, and metabolism, according to a study published online Nov. 11 in the European Journal of Applied Physiology.
The three-day Ultraman includes an initial 6.2-mile open swim and a 90-mile bike ride. On day two, athletes complete a 172-mile bike ride, and on the final day they run a double marathon, or 52.4-miles. During the Ultraman competition last year in Florida, researchers assessed the health of 18 athletes, including four women. The athletes were weighed every morning before they competed, and they also provided urine and blood samples.
The researchers found that, overall, the athletes lost body fat but they didn't lose weight because they retained fluid. They also noted extremely large increases in creatine kinase, C-reactive protein, aldosterone, and cortisol, alongside reductions in testosterone and the testosterone:cortisol ratio. Blood glucose was found to rise in a stepwise manner prior to each stage.
"Given recovery, their insulin sensitivity likely returned to normal, but it was interesting to see how a presumably healthy activity can lead to symptoms associated with being very unhealthy," study coauthor Daniel Baur, of the Florida State University Institute of Sports Sciences and Medicine in Tallahassee, said in a university news release.