In this article we experimentally addressed the relationship between blood glucose levels and performance on cognitive processing and motor coordination tasks. We also aimed to test how are blood glucose levels modified following a 30minutes cognitive and motor strain. Blood glucose level was measured using an Accu-Chek blood-sugar meter before and immediately after the tasks were performed. We applied 3 samples: two of cognitive processing and one of motor coordination. The samples used are - COG test, STROOP and 2HAND COORDINATION of the Vienna Test System–Schuhfried testing battery. The 32 participants completed and signed participation agreements, a form that stated when they last ate or when they had consumed beverage with sugar in their composition, how many hours they slept the night before and how are they feeling/how is their health at the time.