[Plasma catecholamines, metabolic substrates, aerobic and anaerobic capacity during graduated treadmill and bicycle...

Adrenaline, noradrenaline, glucose, lactate, free fatty acids, and glycerine in blood, as well as heart frequency and oxygen intake were examined in 6 healthy male subjects (28 +/- 2.6 years) before, during and after a graduated treadmill (TME) and bicycle ergometer (BE) test. Adrenaline, noradrenaline, the energy supplying substrates, and the oxygen-intake show no differences during TME and BE at given submaximal levels. Noradrenaline is 27% (0.10 less than p less than 0.05) higher, pulse rate is 6% (p less than 0.05) lower, oxygen intake 4% (greater than 0.05) lower, and the glycerine level 25% (0.10 less than p less than 0.05) lower during maximal BE exercise. The tendency toward a higher noradrenaline release during BE exercise can be influenced by a greater static-pressure stress opposed to a dynamic-circulatory stress during TME testing. An increased alphareceptor stimulation leads to a negative chronotropic effect, whose cause is assumed to be a baroreceptor stimulation. The TME induces a higher circulation and a more economic oxygen supplying of the muscles exercised, as well as a favourable fat oxidation, which is recognizable by a more rapid increase of glycerine (0.10 less than p less than 0.05). When referring to exercise acidification (a tendency toward a lower lactate production during submaximal TME testing shows here), oxygen intake capability, energy supplying substrates, and the catecholamines, both forms of ergometer testing are comparable one to another; a falsification appears only when plasma catecholamines and lactate levels are based on the heart frequency, as it is influenced by the form of exercise.