Folk dances are aesthetic conventional activities. Croatian folklore heritage is very rich and the professional ensemble of folk dances with its repertoire contributes to its preservation. Choreographie dance performance requires physical preparedness during rehearsals and performance. The main aim of this research was to determine the physiological load of professional folk dancers during the performance. Partial objectives were to determine the morphological characteristics, functional abilities and differences in physiological load between choreographies, and functional abilities by gender and dance group. The sample of subjects was 28 professional male (N=13) and female (N=15) folk dancers. Morphological characteristics were determined by four anthropometrical measures. Functional abilities were established on the basis of ventilation parameters from the spiroergometry test in the laboratory. The physiological load of dancers during the performance was monitored by the level of heart rate. Central and dispersion parameters were calculated. The normal distribution of variables was tested by Kolmogorov-Smirnov test. Statistically significant differences between female and male dancers were tested by univariate analysis of variance (ANOVA) and Kruskal-Wallis ANOVA. The post-hoc analysis for comparison of results between the groups was calculated for the variables in which statistically significant differences between groups were determined through the analysis of variance, The statistical significance of differences between men and women in different dance choreographies was tested with Student's t-test. On the basis of the determined results it is concluded that professional dancers of Croatian folk dances are exposed to physical activities of high physiological workload during the performance. According to the significant differences in physiological load during the performance between male and female groups of dancers, it was observed that female dancers are under greater physiological load when compared to male dancers. Statistically significant differences were determined in functional abilities between male and female groups of dancers. It was observed that aerobic capacity of the members of the folk dance ensemble are better than the average population, but worse in comparison to athletes. In accordance with the established high intensity activity and based on the values of functional abilities parameters, it is suggested that there is a need for folk dancers to engage in appropriate additional training in order to improve their physical fitness. The obtained findings in this research are very important for planning and programming of an adequate physical preparation for dancers, which will contribute to their better functional status and dance performance.