Biochemical changes in a 100 km run: carbohydrates, lipids, and hormones in serum.

During the 100 km race in Biel, Switzerland, seven-well trained men (age 33.3 +/- 3.5 years; V02 max. 59.9 +/- ml/kg) have been investigated. Their mean running time over the 100 km distance averaged 10.41 +/- 1.25 h. In contrast to almost unchanged blood glucose and lactate concentrations, blood lipids showed significant changes. Triglycerides decreased about two-fold, whereas glycerol and free fatty acids increased to extremely high concentrations (0.628 and 2.44 mmol/l respectively). Plasma insulin after the run was unaffected, whereas growth hormone, aldosterone and cortisol concentrations were significantly increased. With the exceptions of a still significantly elevated aldosterone and lactate concentration as well as a decreased triglyceride concentration all other values in the blood are restored to normal 24 h after completion of the run.