JMIR Publications

ABSTRACT

Background:

High-intensity physical activity (PA) improves health in people living with HIV (PLWH). Even when people have good intentions to engage in PA, they often find it difficult to maintain PA behavior over the long term. Two Minds Theory is a neurocognitive model that explains gaps between people’s intentions and behaviors based on the operations of two independent mental systems. This model predicts that everyday experiences will affect PA, and that factors outside people’s awareness like sleep and stress can have particularly strong effects on PA behaviors.

Objective:

This study was designed to test the effects of daily experiences on PA among PLWH, including measures of people’s conscious experiences using daily electronic surveys, and measures of non-conscious influences using sensor devices.

Methods:

In this study, 55 PLWH wore a Fitbit Alta™ for 30 days to monitor their PA, sleep, and heart rate variability (HRV) as a physiological indicator of stress. Participants also used their smartphones to complete daily eletronic surveys for the same 30 days about their fatigue, self-efficacy, mood, stress, coping, motivation, and barriers to self-management. Time-lagged, within-person multilevel models were used to identify the best prospective predictors of PA, considering PLWH’s daily survey responses and sensor data as predictors of their PA the following day.

Results:

PA varied substantially both between and within persons. The observed pattern demonstrated not only that different people had different average levels of PA, but also that individual PLWH had some days with more PA and other days with less. This suggests an opportunity to intervene based on factors that predict PA on any given day. High-intensity PA was more likely on days when PLWH reported less subjective fatigue the prior day (r = -.48), but was unrelated to actual sleep based on objective sensor measures. High-intensity PA was also predicted by higher HRV (r =.56) meaning less stress, lower HIV-related stigma (r = -.21), fewer barriers to self-management (r = -.34), and lower approach coping (r = -.34). Similar variables predicted lower-level PA measured based on PLWH’s number of steps per day.

Conclusions:

Some predictors of PA, such as HRV, were only apparent based on sensor data, while others such as fatigue were best identified via self-report. The findings about coping were in an unexpected direction, but other findings were in line with the literature. The current study extends our prior knowledge about PA by demonstrating a prospective effect of everyday experiences on PA behavior, in line with the predictions of Two Minds Theory. Clinicians can support PLWH’s PA by helping their patients to reduce daily stress, fatigue, or barriers to self-care. Clinical Trial: N/A (not a clinical trial)