Physical activity among adults with obesity: testing the Health Action Process Approach.
OBJECTIVE
This study tested the applicability of the Health Action Process Approach (HAPA) in a sample of obese adults in the context of physical activity.


METHODS
Physical activity was assessed along with motivational and volitional variables specified in the HAPA (motivational self-efficacy, outcome expectancies, risk perception, intention, maintenance self-efficacy, action planning, coping planning, recovery self-efficacy, social support) in a sample of 484 obese men and women (body mass index ≥ 30 kg/m2).


RESULTS
Applying structural equation modeling, the fit of the HAPA model was satisfactory-χ²(191) = 569.93, p < .05, χ²/df = 2.98, comparative fit index = .91, normed-fit index = .87, and root mean square error of approximation = .06 (90% CI = .06, .07)-explaining 30% of the variance in intention and 18% of the variance in physical activity. Motivational self-efficacy, outcome expectancies, and social support were related to intention. An association between maintenance self-efficacy and coping planning was found. Recovery self-efficacy and social support were associated with physical activity. No relationships were found between risk perception and intention and between planning and physical activity. The assumptions derived from the HAPA were partly confirmed and the HAPA may, therefore, constitute a theoretical backdrop for intervention designs to promote physical activity in adults with obesity.
Department of Health Psychology, Freie Universität Berlin.
Linda
L
Parschau
Department of Health Psychology, Freie Universität Berlin.
Milena
M
Barz
School of Psychological Science, Oregon State University.
Jana
J
Richert
Department of Health Psychology, Freie Universität Berlin.
Nina
N
Knoll
Jacobs Center on Lifelong Learning and Institutional Development, Jacobs University Bremen.
Sonia
S
Lippke
Department of Health Psychology, Freie Universität Berlin.
Ralf
R
Schwarzer
D000223:Adaptation, Psychological / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D015438:Health Behavior; D006801:Humans; D033182:Intention; D008297:Male; D008875:Middle Aged; D009042:Motivation / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity / Q000523:psychology* / Q000534:rehabilitation; D020377:Self Efficacy; D012944:Social Support; D011795:Surveys and Questionnaires; D055815:Young Adult