Biochemical, hematological and endocrinological parameters during repeated intense short-term running in comparison...

In order to see the differences in the acute effects of two kinds of running on biochemical, hematological and hormonal parameters, we investigated in one 24 h race (same exterior conditions) two groups of runners (NR = nonstop runners; RR = relay runners). From each participant blood samples were taken before, 3 times during and after the race. In both groups the lipid parameters cholesterol, triglycerides and LDL-cholesterol declined significantly, triglycerides even to 40% of their initial value, whereas HDL-cholesterol increased significantly. Renal parameters showed similar increases in both groups except for uric acid, which rose by 73% in RR compared with only 23% increase in NR. A difference was also found in the lactate and glucose concentrations, showing a four-fold increase and a 34% increase at 4 h respectively in RR, whereas the NR remained constant. Changes in the hematological parameters were similar in both groups. Cortisol and prolactin showed similar alterations during the race but LH and testosterone declined to approximately half of their initial concentration (p greater than 0.05) in NR after 4 to 8 h, in contrast to RR, where the concentration of LH or testosterone remained constant or changed only moderately but insignificantly during the race. Our investigation indicates that in ultra-long-distance running and intense short-term exercise performed under the same exterior conditions, many parameters show similar changes but great differences can be found as well if certain hormones, glucose metabolism and renal parameters are considered.