Changes in the EEG spectrum at a two-week intensive endurance training

Marathon runners in the course of a two-week endurance training, (i.e. in the beginning, after one and after two weeks) and processed by the off-line method of fast spectral analysis. Simultaneously biochemical parameters were monitored which indicated after one week the development of the so called "pseudouremic syndrome of top athletes" of not too great intensity. In the second week of the experiment therapeutic intervention was made in six subjects, i.e. reduced protein supply, greater amount of glucose, application of Ca-lactate and higher amount of liquids. This intervention eliminated entirely the signs of pseudouremic syndrome. The EEG showed in both groups a decrease in theta activity (4-6 Hz) and an increase of the slow alpha component and subtheta activity (6-8 Hz), with no basic difference between the intervened and control group. Thus the changes may be rather attributed to fatigue and perhaps to a poorer supply of the CNS with oxygen and glucose.