Introduction: Nowadays, stress has been become either an integral component or the main characteristic among the lives. Scientists believe that a little amount of stress could be beneficial and lead to effective learning and increasing performance. However, it is accepted that high level of stress could bring about decreasing performance and finally mental disorder.
Methodology: The aim of this study was to determine sources of stress in national swimmers. The method was conducted by qualitative and phenomenological approach based on purpose sampling. 9 Athletes were selected as participants and interviewed for the research objects. Data was analyzed using a seven-step Colonizer's method. Firstly, in order to comprehensive understanding of the athletes’ statements, they were investigated intently. The word and statements related to stress were extracted and classified in the next steps. Then, the codes also were extracted followed by integration of duplicated codes and new classification. Ultimately, the formulated means were identified as descriptive codes. In the final step, all the obtained ideas were integrated in the form of detailed description following its interpretation codes. These codes contain the meanings that are given to descriptive codes.
Results: Data analysis demonstrated that descriptive codes of stress resources included: internal source of stress in the training phase, internal source of stress in the competition phase, external source of stress in the training phase, and external source of stress in the competition phase.
Discussion: Results showed that the national swimmers are influenced by internal and external source of stress in the training and competition phases. Thus, their demands and needs should be considered in the psychological interventions. Furthermore, the results demonstrated that the athletes are influenced by external source of stress which should be also considered by coaches and officials in order to adopt proper modulator methods.