Associations Between Cardiovascular Reactivity and Automatic Evaluation of Physical Activity and Sedentary Behaviors

Abstract

Effort mobilization, or the amount of resources individuals mobilize to execute behavior, is central to the dual-process theory. One’s evaluation or perception of task difficulty (target behavior) is directly related to effort. Automatic or habitual behaviors require little effort, while reflective or controlled processes require greater effort mobilization, and even greater effort when behavioral automaticity and the goal task conflict. Cardiovascular (CV) reactivity to cognitive challenge is an objective and reliable measure of effort mobilization, but has yet to be evaluated in the automatic evaluation (AE) of PA behavior. PURPOSE: To explore relationships among CV reactivity, AE and reflective measures of PA behavior. METHODS: This pilot study includes a subset of 30 subjects (57% women, 24±10 y, 27±5 kg/m2) from a larger project examining interactions between AE and reflective processes in relation to PA behavior. A computerized test (Single Category Implicit Association Test [SCIAT]) was used to measure AE of PA behaviors (positive scores reflected positive AE of the target behavior). Heart rate (HR) and systolic blood pressure (SBP) were measured continuously and noninvasively using a finger cuff. CV reactivity was quantified using average values obtained during the SCIAT and percentage change (∆) from rest. Accelerometers measured habitual PA (min/d) and questionnaires captured reflective PA outcomes (e.g., intention, enjoyment). Bivariate correlations were used to explore the relationships among variables (α=0.05). RESULTS: SBP during the SCIAT correlated with habitual PA (r=0.41). HR during the SCIAT correlated with intention to perform exercise (r=-0.51) and PA enjoyment scale (r=-0.56), while ∆HR correlated with light intensity PA SCIAT scores (r=-0.40; all p≤0.03). CONCLUSIONS: Lower CV reactivity during the SCIAT was related to positive AE toward PA behavior and greater PA intention, suggesting that these subjects found PA stimuli to be less stressful (required less effort). Conversely, CV reactivity was higher among those with positive AE toward sedentary behavior, suggesting that PA stimuli was more stressful (required greater effort). By focusing efforts on changing how individuals perceive PA, future PA guidelines may be more successful in increasing long-term PA adherence.