The Role of Physical Activity and Sedentary Behavior in Predicting Daily Pain and Fatigue in Older Adults: a Diary Study

Background Little attention has been paid to within-person daily associations among light physical activity (PA), moderate-to-vigorous physical activity (MVPA), and sedentary behavior (SB) with subsequent bodily pain and fatigue. Daily reports of pain and fatigue are less likely to be affected by recall bias and to conflate days of high and low pain/fatigue into one overall score. Purpose The purpose of this study was to examine daily within-person associations between pain, fatigue, and physical health and ascertain whether such associations are moderated by individual differences in these variables. Methods Participants were 63 community-living older adults (female n = 43, mean age = 70.98 years). Questionnaires measured typical levels of PA, SB, bodily pain, fatigue, and physical health. Subsequently, on a daily basis over a 1-week period, participants' levels of light PA, MVPA, and SB were measured using accelerometers. Participants completed a questionnaire rating their pain and fatigue at the end of each day. Results Multilevel modeling revealed positive within-person associations between daily light PA, daily MVPA, and pain, as well as negative within-person associations between daily SB and pain. For individuals with higher typical levels of fatigue, there was a negative association between daily light PA, MVPA, and fatigue. For individuals with better levels of physical health, there was also a negative association between daily MVPA and fatigue. For those with higher typical levels of fatigue and better levels of physical health, there was a positive association between daily SB and fatigue. No such interaction effects were found between high levels of typical pain and PA or SB. Conclusions Our findings indicate that efforts to promote daily PA in older adults might be more effective for those who report high typical levels of fatigue and physical health, compared to those who report high levels of daily physical pain.