Competencies for health‐enhancing physical activity are associated with body mass: results of an updated data pooling across 18 samples

Objective: Although previous studies have illuminated associations between body
mass and physical activity (PA), there have been scant insights regarding the physical,
cognitive, and motivational determinants of PA in relationship to body mass. This
study aimed to model courses of competencies for health-enhancing PA across the
spectrum of BMI.
Methods: We used cross-sectional data of 3670 individuals (mean [SD]: BMI, 25.54
[5.71] kg/m2
; age, 46.11 [14.96] years) from a large data pooling with 18 primary
samples employing the PA-related health competence (PAHCO) instrument.
ANCOVA determined differences in 10 PAHCO indicators by BMI categories (under-
weight, normal weight, overweight, and obesity). Covariate-adjusted multilevel
models described the nonlinear courses of the PAHCO indicators across the BMI
spectrum.
Results: The levels of all 10 PAHCO indicators differed significantly among the
BMI categories (F ≥ 14.8; p < 0.001). All competencies for health-enhancing PA
could be best described by cubic functions having their maximum around normal
weight while regressing with underweight and with increasing grades of obesity
(0.02 ≤ R2
marg ≤ 0.31)