Disentangling the effects of choice and intensity on affective response to and preference for self-selected- versus imposed-intensity physical activity

Abstract

ObjectiveTo examine the independent effects of physical activity (PA) intensity and choice of PA intensity when comparing affective response to and relative preference for self-selected-intensity versus imposed higher intensity PA. DesignWithin-subjects experiment. MethodsTwenty-nine healthy, low-active women completed four PA bouts over two sessions. The first session consisted of a one-third mile self-selected-intensity treadmill walk during which the speed was recorded, but was not visible to the participants. The second session consisted of three, counterbalanced, one-third mile treadmill conditions: (a) self-selected intensity, (b) same intensity as recorded for the first-session-self-selected-intensity walk, but with the intensity imposed by the experimenter (i.e., yoked-self-selected intensity), and (c) intensity set at 20% higher than the first-session-self-selected-intensity walk (imposed higher intensity). Acute affective valence (pleasure/displeasure) was recorded prior to, during, and following each walking bout. Preference for each walking intensity was assessed using a behavioral-choice paradigm. ResultsContrary to hypotheses, there was no effect of condition on acute affective valence. However, consistent with hypotheses, there was a linear trend, F(1, 22) = 11.00, p = .003, indicating preference in descending order from self-selected-intensity to yoked-self-selected-intensity to imposed higher intensity PA. ConclusionsBoth choice over the intensity and a lower intensity per se contributed to greater preference for self-selected-intensity over imposed higher intensity PA among healthy low-active women; however, there was no evidence to support the notion that affective response to PA mediated this relationship.