Objectives:
The purpose of the study was to evaluate the impact of physical activity of university staff members on their well-being and work performance. In the course of analyses, the author attempted to find an answer to the question to what extent physical activity contributes to the improvement of well-being of the workforce.

Material and methods:
The study was based on a diagnostic survey method employing a questionnaire.In the course of analyses, the authors attempted to find an answer to the question to what extent physical activity contributes to the improvement of internal and external well-being of the Siedlce University of Natural Sciences and Humanities staff.

Results:
The analyses confirmed that the stimulation of physical activity in the workplace may benefit employee well-being on many levels. The results of the study demonstrated that physical activity has a positive impact on emotional, psychological, and social well-being of university staff, and that it augments the efficiency, focus, and creativity in the workplace. The research findings may be of importance to employees, employers, and decision-makers involved in the taking of decisions about health promotion programmes in the workplace. The study may contribute to the promotion of the concept of well-being, above all, in non-profit organizations, where new tendencies in human resource management are typically introduced later than they are in commercial organizations

Conclusions:
Against a backdrop of the conducted analyses, the emphasis on employee well-being needs to be viewed now as one of the best investments a modern organization may make. Creating an optimal environment in which employees can fulfil their potential is one of the key factors in the long-term effectiveness of an organisation. Healthy and fit staff mean an efficient organisation.