RESUMO
AIMS AND OBJECTIVES: To explain the transitional process that individuals with unexplained chest pain undergo while participating in an exercise training programme over time. BACKGROUND: Angina-like chest pain in patients with no obstructive coronary artery disease is a growing problem. Functional limitations, restricted daily activities and reduced quality of life are reported. In addition, physical activity is avoided in this population. DESIGN: The study follows a qualitative classic grounded theory (Glaser ). METHODS: Three times a week for 12 weeks, twelve patients with no obstructive coronary artery disease participated in a high-intensity aerobic exercise training programme supervised by physiotherapists and nurses. The data collection was based on diaries and interviews about the experience and analysed according to the principles of classic grounded theory. RESULTS: The core category was identified as 'confronting one's vulnerability' and included three subcategories: 'balancing existential uncertainty', 'transforming bodily perceptions' and 'becoming a more capable person'. CONCLUSION: The transition was described as a process of becoming more capable. Health professionals should be aware of the significance of high-intensity exercise training for people with unexplained chest pain and of the underlying dimension of vulnerability. RELEVANCE TO CLINICAL PRACTICE: Understanding the transition process that people with unexplained chest pain undergo while participating in a high-intensity exercise training programme promotes a person-centred approach. Taking this substantive theory into consideration will improve the prerequisites for establishing person-centred care.