Identifying Potential Barriers to Physical Activity Adherence: Anxiety Sensitivity and Body Mass as Predictors of Fear During Exercise

Abstract

A growing body of work suggests that obese adults are less likely to adhere to exercise than normal-weight adults because they experience greater levels of discomfort and distress during exercise sessions. The present study introduces and provides a preliminary test of the hypothesis that the distress experienced during exercise among persons with elevated body mass index is particularly high among those who fear somatic arousal (i.e. elevated anxiety sensitivity [AS]). Young adults were randomly assigned to complete 20 min of treadmill exercise (at 70% of their age-adjusted predicted maximum heart rate) or 20 min of rest. Body mass, AS, and negative affect were measured at baseline, and fear was measured at 4-min intervals during the experimental phase. Consistent with the authors' hypothesis, there was a significant Exercise x BMI x ASI interaction (sr(2) = .08), suggesting that the greatest fear levels during exercise were observed among participants with high body mass, but only if they also had elevated AS. These findings offer a new approach for identifying specific vulnerable individuals and have clear clinical implications, given that the amplification factor of AS can be modified with clinical intervention.

Anxiety sensitivity predicts increased perceived exertion during a 1-mile walk test among treatment-seeking smokers

“…Taken together, anxiety sensitivity does not appear to influence observed HR during the bout of moderate-intensity exercise, however does “amplify” the subjective experience of exertion. The current results extend existing prior findings that examined the link between anxiety sensitivity and lower levels of cardiorespiratory fitness in a separate sample of sedentary treatment-seeking smokers (Farris et al, 2016), and parallel findings non-specific to smokers that indicate anxiety sensitivity predicts increased negative affect (i.e., fear) during exercise, particularly among individuals with higher body mass index (Smits et al, 2010). Of note, RPE is a subjective rating of exertion and effort, including breathlessness and fatigue during exercise, and while is distinct from the affective response to exercise, they may certainly influence one another (Baldwin et al, 2016).…”

“…The perception of being evaluated could have influenced ratings of RPE. Second, the tendency to be aware of and negatively appraise interoceptive sensations is likely influenced by a host of individual difference factors (not limited to anxiety sensitivity), including genetic factors (Bryan, Hutchison, Seals, & Allen, 2007) and body weight (Ekkekakis & Lind, 2006; Smits et al, 2010). While beyond the scope of the current investigation, future work could examine these and other individual differences factors that may influence the experience of exercise.…”

“…J. Zvolensky, Stewart, Vujanovic, Gavric, & Steeves, 2009). Anxiety sensitivity is also linked to physical inactivity (Smits, Tart, Presnell, Rosenfield, & Otto, 2010). Indeed, among community and clinical samples (non-smoking specific), anxiety sensitivity is negatively associated with exercise frequency and fitness levels (Goodin et al, 2009; McWilliams & Asmundson, 2001; Sabourin, Hilchey, Lefaivre, Watt, & Stewart, 2011; Smits & Zvolensky, 2006), and predicts lower engagement in exercise (Hearon, Quatromoni, Mascoop, & Otto, 2014; Moshier, Szuhany, Hearon, Smits, & Otto, 2016).…”

“…Theoretically, individuals with elevated anxiety sensitivity may be unwilling to engage in physical activity due to the perceived dangerousness or harmfulness of the interoceptive sensations evoked during exercise (Smits et al, 2010). Perceptions of harm may in turn amplify the experience of these somatic sensations and emotional distress, thus producing aversion to exercise and subsequent avoidance of exercise (Otto et al, 2016).…”

“…It is unknown how anxiety sensitivity is related to perceived exertion (subjective effort) during activity bout of aerobic exercise. Given higher ratings of perceived exertion during exercise are associated with physical inactivity (Williams et al, 2008) and anxiety sensitivity is associated with greater negative affect during exercise (Smits et al, 2010), it is possible that individuals with higher levels of anxiety sensitivity may perceive that they are exerting more effort during a during aerobic exercise, which could further contribute to the amplified experience of interoceptive distress and subsequent avoidance of physical activity.…”