Modeling longitudinal variation in affective response to exercise across a 16-week randomized control trial (RCT)

Area of Science:

• Behavioral health
• Exercise science
• Public health interventions

Background:

• Physical inactivity is a major public health threat.
• The Science of Behavior Change (SOBC) promotes an experimental medicine approach for interventions.
• Understanding exercise's impact on affective response is key for adherence.

Purpose of the Study:

• To examine how exercise training intensity and duration influence affective response and perceived exertion.
• To assess the relationship between exercise experience and long-term exercise engagement.
• To inform the development of future physical activity interventions.

Main Methods:

• 201 physically inactive adults were randomized into 4 groups varying in exercise intensity (moderate/vigorous) and duration (short/long) for 16 weeks.
• In-bout affective response and ratings of perceived exertion (RPE) were measured periodically.
• Cardiorespiratory fitness (VO₂max) and 6-month exercise behavior were assessed.

Main Results:

• Affective response to exercise did not change significantly over time, but RPE slightly decreased.
• Vigorous intensity exercise was associated with more negative affect and higher RPE.
• Baseline positive affective response predicted future exercise minutes, but average affective response did not.

Conclusions:

• Exercise training, regardless of intensity or duration, did not improve average affective response over 16 weeks.
• Vigorous exercise may elicit less positive affective responses.
• Targeting baseline affective responses may be crucial for promoting sustained exercise behavior.