This study examines the ability to maintain attention during a serial reaction time task performance in expert handball players and non-athletes. Participants performed a protocol with the FITLIGHT Trainer™ consisted of 10 series of simple motor reaction task to visual stimuli. Each of the 10 series included 22 reactions. Ability to maintain attention was determined by analyzing the variability in results during testing, e.g. the total time of test execution and the average reaction time to visual stimulus in each subsequent series.