[New criteria for prediction of individual endurance of physical stress]

A team of eight triathlon athletes was tested for endurance to extreme physical stress during training session. Two new functional parameters were analyzed, i.e. the cell membrane beta-adrenoreactivity (beta-ARM) and activity of leukocyte tyrosine hydroxilase (TH) as a key enzyme of the dophaminergic system. In four athletes who had been included in the national team at a later date beta-ARM and Kth values were 2-3-fold beyond the physiological norm, whereas in the other four (reserves) the parameters were below the upper limits. These data suggest that abnormal beta-ARM and Kth values can be treated as biochemical prognostic criteria for endurance of extreme phyical stress.