Methods of psychophysiological testing and electroencephalography were used to study the effect of physical activity on cognitive functions (in particular, in the decision-making ability test) and brain bioelectrical activity (in particular, the power of the EEG amplitude in the beta and delta ranges) in athletes of various specializations. It is shown that when performing psychological tests before the load, athletes involved in cyclic types of load demonstrate better results than weightlifters – they have a higher learning rate, a higher percentage of correct answers, a shorter response time and a faster attention switching speed. The results of psychological tests before exercise in the control group were lower than in athletes, but higher than in weightlifters. The single-time physical load of a cyclic nature did not affect the results of the Iowa Gambling Task in untrained volunteers and weightlifters, but contributed to the improvement of test results in athletes training in cyclic sports – the learning rate and the percentage of correct answers increased. When performing a cognitive test, athletes noted an increase in the power of the spectra of the delta (and in weightlifters – and theta) range to a greater extent than in the control. In contrast to the control group, physical activity in athletes more often contributes to a decrease in the power of the EEG spectra, especially in the beta and delta ranges. The revealed differences in the results of psychophysiological tests in athletes of various specializations and untrained volunteers are largely determined by the features of the functional activity of various parts of the cortex, which is reflected in the characteristics of patterns of brain bioelectrical activity.