Association of patterns of moderate-to-vigorous physical activity bouts with pain, physical fatigue and disease severity in women with fibromyalgia: the al-Ándalus project

OBJECTIVES: i) To examine the associations of non-bouted moderate-to-vigorous physical activity (MVPA) and patterns of MVPA in bouts ≥ 10 min with pain, physical fatigue and disease severity in women with fibromyalgia, and test whether these associations are independent of sedentary time (ST) and physical fitness (PF). DESIGN: Cross-sectional study carried out from November 2011 to January 2013 SETTING: University facilities and fibromyalgia associations. PARTICIPANTS: 439 (51.3±7.6 years old) women with fibromyalgia. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: ST and MVPA were measured with triaxial accelerometry, and PF with the Senior Fitness test battery. We assessed pain, physical fatigue and disease severity with diverse questionnaires. RESULTS: Total time in non-bouted MVPA only was independently associated with lower physical fatigue (B=-0.012; P=0.010) and disease severity (B=-0.068; P=0.007) in women with fibromyalgia, regardless of PF but not of ST. Patterns of bouted MVPA were overall associated with symptoms independently of ST or PF. The strongest regressor was the maximum time in MVPA bout (min/bout), which was consistently and independently associated with pain, physical fatigue and disease severity after controlling for ST or PF (all, P≤0.002). Patients meeting bouted physical activity guidelines displayed lower disease severity than those not meeting guidelines (bouted or non-bouted) and those meeting non-bouted physical activity guidelines (all, P≤0.008). CONCLUSIONS: Patterns of MVPA performed in bouts ≥ 10 min were overall consistently and independently associated with core symptoms (pain and fatigue) in fibromyalgia and the overall disease severity, regardless of ST or PF. The results suggest that longer bouts of continuous MVPA are associated with better symptoms profile in this population, which needs to be corroborated in longitudinal research