The Influence of Physical Activity and Positive Affect on the Relationship between Pain Severity and Cognitive Performance in Women with Fibromyalgia.

Fibromyalgia, characterized by chronic pain and cognitive impairments, significantly impacts patients' quality of life. Physical exercise has been shown to improve cognitive functions and reduce pain severity. Additionally, positive affect enhances cognitive flexibility and facilitates better adaptation to chronic pain, suggesting that combining physical activity and positive affect could mitigate cognitive deficits in fibromyalgia patients. Objectives: The objective of this work is to explore the relationship between pain severity and cognitive performance through time spent doing moderate physical activity while taking into account the role of positive affect in fibromyalgia. Methods: This prospective study was structured into two phases of evaluation. First, pain severity, positive affect, and time spent performing moderate physical activity were evaluated, and one week later cognitive performance (assessed through the Stroop test) was also evaluated. The final sample consisted of 231 women with fibromyalgia. Moderated mediation analyses were performed using PROCESS. Results: The moderated mediation model showed that the effect of moderate physical activity on the relationship between pain severity and cognitive performance was significant for low levels of positive affect but not for moderate or high levels. That is, the indirect effect of pain intensity on cognitive performance through time spent doing moderate physical activity only has an effect when patients with fibromyalgia present low levels of positive affect. However, there was no significant indirect effect in the simple mediation model. Conclusions: The findings of this study underscore the importance of considering the level of positive affect when examining the impact of moderate physical activity on cognitive performance in women with fibromyalgia.