Exercise does not feel the same when you are overweight: the impact of self-selected and imposed intensity on affect and exertion.
OBJECTIVE
The lower rates of adherence to physical activity commonly found among overweight adults compared to their normal-weight counterparts might be due to the activity being experienced as more laborious and less pleasant, particularly when its intensity is prescribed (or imposed) rather than self-selected.


METHODS
Within-subject design, with two 20-min sessions of treadmill exercise, one at self-selected speed and one at imposed speed, 10% higher than the self-selected.


METHODS
A total of 16 overweight (BMI: 31 kg/m2) and 9 normal-weight (BMI: 22 kg/m2) previously sedentary but healthy women (age: 43 years).


METHODS
Heart rate, oxygen uptake relative to body weight, and ratings of perceived exertion and pleasure-displeasure were assessed every 5 min.


RESULTS
The overweight women showed higher oxygen uptake and perceived exertion than the normal-weight women during both sessions. Although the two groups did not differ in ratings of pleasure-displeasure during the session at self-selected speed, only the overweight women showed a significant decline when the speed was imposed.


CONCLUSIONS
Imposing a speed that is just 10% higher than what overweight women would have self-selected led to a significant decline in reported pleasure. Over time, this could diminish the enjoyment of and intrinsic motivation for physical activity, reducing adherence.
Ekkekakis
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Department of Health and Human Performance, Iowa State University, IA 50011, USA. ekkekakis@iastate.edu
Lind
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D000328:Adult; D015444:Exercise / Q000502:physiology / Q000523:psychology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000523:psychology*; D050177:Overweight / Q000502:physiology; D010101:Oxygen Consumption; D010349:Patient Compliance; D010465:Perception; D005082:Physical Exertion; D016138:Walking