Daily intra-individual variability of positive but not negative affect impacts moderate to vigorous physical activity

Abstract

Abstract Introduction The World Health Organization recommends moderate to vigorous physical activity (MVPA) for 150 minutes per week to reduce the risk of primary or secondary cardiovascular diseases (CVD). Adherence to these recommendations is only around 30% in the US. Identifying reliable barriers or facilitators of time spent in MVPA is a critical component to primary and secondary CVD prevention. Negative affect, including feelings such as being sad, nervous, and restless, is known to diminish time spent in MVPA, whereas positive affect, which includes feelings such as being calm, happy, or full of life is associated with MVPA increases. Relatedly, variability in positive but not negative affect is associated with poorer physical health. What is unclear is how intra-individual variability of positive and negative affect may influence MVPA. Research question What is the influence of variations (i.e. intra-individual day-to-day) in positive and negative affect on variations in MVPA? Method. Guided by the individual and self-management theory, a secondary analysis was conducted of data from a nationwide US sample of participants. Using data from the Midlife in the United States (MIDUS) Refresh Wave Study Daily Diary Project, we analyzed eight consecutive days of affect and MVPA assessments in a sample of 553 healthy participants (54% women, 86% white, mean age = 48.7 years). Latent trajectory models were computed to determine the influence of daily positive and negative affect on daily MVPA. Results Affect variability, calculated as the standard deviation of daily positive and negative affect, was positively correlated with MVPA variability. An autoregressive cross-lagged latent trajectory model provided the best fit to examine relationships between positive affect, negative affect, and MVPA (χ2=946.54, df=379, p<0.001; CFI=0.95; RMSEA=0.05, SRMR = 0.06). Positive, but not negative affect, intercepts were significantly correlated with MVPA trajectories (r=0.19, p<0.05). Individuals who initially begin the eight day time span with a higher reported positive affect show a modest increase in MVPA over the same time period (r=0.19, p<0.001). By contrast, individuals evidencing increases in positive affect over the time span showed a decreased rate of change in MVPA over that same time (r=−0.32, p<0.001). Conclusion The association of positive affect to MVPA necessitates a complex analysis to more fully understand intra-individual-level interactions. Relatively higher positive affect with fewer fluctuations was associated with greater MVPA. These intriguing preliminary findings must be considered in light of important limitations (e.g., only eight days of data; affect and MVPA do not necessarily follow diurnal patterns). Still, findings support the view that beginning with positive affect may lead to stability in time spent in MVPA. Funding Acknowledgement Type of funding source: None