The objective of this work was to study major early signs of overstrain in athletes based on dynamic patterns of the most sensitive psycho-physiological symptoms during physical exercises and the post-training recovery period. The study included sport game players examined in the contest season. It was shown that reduction of simple visiomotor reaction time soon after cessation of training compared with that at rest may be indicative of adequate response of the central nervous system to physical exercise that activates central regulatory mechanisms under physiological conditions. It is concluded that these observations may be of use for the choice of exercise intensity on an individual basis and timely correction of training plans.