The present work is a quality-quantitative study of cause-effect type. The objective of this study was to investigate the effect of a Labor Gym (LG) program in mental workload of workers from rectory of the Universidade Estadual do Oeste do Paraná (Unioeste) Cascavel. The sample consisted of 35 employees. For data collection, it was used the NASA-TLX questionnaire to evaluate the mental workload of employees. Then, the participants performed sessions of LG, totaling 20 classes. After this period the employess were re-evaluated. To characterize the sample, data were tabulated and a descriptive analysis was performed using the SPSS 15.0. The interpretation of the NASA-TLX questionnaire was based on its own methodology. Before the LG sessions, the total average dimensions analyzed was 79 (sd: 11,05), representing a high rate of mental workload. After the period of LG, the total average of final mental workload decreased, but it remained with a high rate (x:75, sd: 13.42). In relation to the comparative analysis of the initial and final averages of mental workload, by t test (bipolar), there was no significant difference (p = 0.071668).