Exploring real-world acute associations between physical activity and bodily pain in middle-aged and older adults.

Introduction: Acute real-world associations between moderate-to-vigorous physical activity (MVPA), sedentary behavior, and daily fluctuations in pain levels of older adults are not well-understood. Methods: Participants (n = 46, age 55-85 years) completed questionnaires including the Graded Chronic Pain Scale (typical pain levels) and Tampa Scale of Kinesiophobia. Participants wore an accelerometer for 7 consecutive days to measure MVPA and sedentary time. During the same 7-day period, participants completed daily ecological momentary assessments (EMAs) of their bodily pain on a 0 to 10 scale using a smartphone app. Linear mixed models examined within-person associations between EMA pain intensity rating and the prior hour's PA levels and cross-level interactions. Results: Greater sedentary minutes in the hour before the EMAs predicted greater bodily pain, with characteristic pain moderating this relationship. A positive relationship was shown between sedentary minutes and pain intensity at higher characteristic pain levels. Kinesiophobia moderated the effect of hourly MVPA minutes on bodily pain. For those with relatively lower kinesiophobia, greater minutes in MVPA predicted lower pain; however, no relationship existed between MVPA and pain for those with higher kinesiophobia. Conclusion: Hourly MVPA acutely influenced subsequent bodily pain in the natural environment of middle-to-older aged adults with musculoskeletal pain.