Changes in blood morphology and chosen biochemical parameters in ultra-marathon runners during a 100-km run in relation to the age and speed of runners A Polish group according to various laboratory values measured at a 100 km run and examined whether the changes in values depend on the age of the runners.They have decreased in 14 men at a 100 km run before, during and after the run blood values. It came to an increase in myoglobin and bilirubin.The change in the number of white blood cells correlated with the muscle damage.
It showed a hypercalemia, but no hyponatemia. The laboratory changes were also independent of the age of the runners. The work can be found under https://pubmed.ncbi.nlm.nih.gov/27518889/