A Trial of an Affect-Guided Physical Activity Prescription
Condition: Physical Activity
Study type: Interventional

Summary: 
      Despite awareness of the benefits of engaging in regular physical activity, at least 50% of
      adults in the US do not meet recommended guidelines for physical activity. One potential
      explanation for this lack of regular physical activity is that people often experience
      exercise as affectively unpleasant. Evidence suggests that the more positively people
      experience exercise (i.e., the better they feel while exercising), the more likely they are
      to engage in regular physical activity. This may be especially true for people in poor
      cardiorespiratory condition. In this randomized trial, investigators compared the effects of
      an affect-guided exercise prescription (intervention) to a heart rate-guided exercise
      prescription (control) on change in physical activity minutes among previously underactive
      adults. Investigators also tested whether the effect of the intervention was moderated by
      differences in cardiorespiratory fitness.
    

Detailed description: 
      Regular physical activity has many benefits for overall health and well-being, and current
      public health guidelines recommend at least 150 minutes per week of moderate-to-vigorous
      intensity activity to attain these benefits. Despite the many benefits of regular activity,
      the majority of adults in the US fail to meet recommendations for regular physical activity.
      One potential explanation for suboptimal levels of physical activity is that exercise is
      often experienced as affectively unpleasant. Recent work has demonstrated that the more
      positive people feel during exercise, the more likely they are to engage in regular physical
      activity. Affective response to exercise is modulated by the intensity of the activity: at a
      vigorous intensity, affective response is almost uniformly negative and unpleasant, whereas
      at a moderate intensity, there is more inter-individual variability in affective response.
      Whether the intensity of the exercise is self-selected or imposed also influences the
      affective response to exercise, with self-selected intensities being experienced as more
      pleasant. Current recommendations for engaging in physical activity focus on the type of
      training intensities most likely to result in a negative affective response. The purpose of
      this pilot trial was to test the effects of an exercise prescription focused on the
      maintenance of positive affect during exercise. Investigators randomized participants to one
      of two exercise prescription conditions: (1) an affect-guided prescription focused on
      maintaining a positive affective response (intervention), and (2) a heart rate-guided
      prescription focused on maintaining a moderate intensity (control). Investigators tested the
      effects of these two exercise prescriptions on changes in subsequent physical activity after
      one week and one month among a sample of underactive adults. Investigators also tested
      whether the effect of the intervention was moderated by differences in cardiorespiratory
      fitness.
    

Intervention name(s): Positive affective response; Moderate-intensity heart rate
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Participants adjust the intensity of their exercise to maintain a pleasant affective response.; Participants adjust the intensity of the exercise to maintain a heart rate in the moderate range (64-76% of their HRmax).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention