Background: Knowledge is needed concerning whether intense prescribed exercise interventions are effective in regards to long-term effects on physical activity levels. A successful and lasting outcome of a behaviour-change intervention is believed to be contingent on the inclusion of psychological issues such as self-rated quality of life and self-rated health. This study extends previous research conducted on the long-term influence of prescribed exercise on psychosocial issues. Specifically, it was analysed if participants’ level of self-rated health (good or poor) at baseline would be decisive for the level of physical activity in the long term. Methods: This study included a baseline analysis of participants in a treatment group (TG) and follow-up after 4, 10 and 16 months. The TG included individuals with lifestyle diseases who followed supervised group-based training and received motivational counselling. The TG was divided into “good” and “poor” self-rated health at baseline. Linear growth curve analyses (multilevel linear regression) were used to examine the data. Results: The results yielded a statistical significant difference of 1.71 metabolic equivalents (MET) between participants with good versus poor health at baseline. Also, a difference of MET was observed at 10 months. MET increased by 0.85 units for participants with good self-rated health (SE = 0.094) from baseline to 16 months, though the increase between subsequent points in time was small and non-significant. In contrast, considerably more variation in the development of MET over time was observed among participants with poor self-rated health. Overall, MET increased by 2.53 units across the whole time span. Results were influenced by the overall proportion of drop-out for participants with good and poor self-rated health with values of 28% and 79%, respectively. Conclusions: Exercise on Prescription (EoP) improves levels of physical activity (MET) of participants with good and poor self-rated health in the long term enough to accommodate national guidelines of levels of physical activity. Participants with poor self-rated health will improve their level of physical activity to a clinical relevant level in the long term, if they manage to stay compliant during the observation period. An assessment of good and poor self-rated health supplemented by a discussion of psychical and physical domains of self-rated health as barriers by the general practitioner (GP), could possibly enhance compliance and thereby long-term adherence to physical activity.
Sport Science Review, 2011, Vol XX, Issue 5-6, p. 73-94