Objective: Volleyball is one of the most popular team sports in the world. As this is a non-contact sport, it is also regarded as a pleasant and safe form of recreation. However, there are commonly known reports about serious injuries which players who represent the highest level of sport performance suffer from. Attempts have been undertaken to define the scale of changes of health-related physical fitness components of the players participating in the starting season of the extra league of Polish Volleyball League. Method. Using the selected attempts of Eurofit test, health-related fitness features of the 12 players were examined at the beginning and at the end of the starting season in the following scope: flexibility, static arm strength, abdominal strength and endurance. In addition, explosive leg power as the most characteristic part of special volleyball skills was measured as well as the basic values of morphological features. Results. With the exception of flexibility, the test results showed a negative effect of starting season on the level of the physical fitness components examined. Not only did the components relate to performance-related fitness deteriorated, but also the health-related ones did. Thereby, the research results demonstrate negative effects of intensive performance of physical activity which is widely considered as beneficial for health. Conclusions were made about the necessity of selecting the intensity level of exercise which matches one's individual abilities. In case of professional sport, conclusions suggest paying attention to maintaining appropriate configuration of health-related physical components.