Body Satisfaction, Exercise Dependence, and White Matter Microstructure in Young Adults

Self-body satisfaction is considered a psychological factor for exercise dependence (EXD). However, the potential neuropsychological mechanisms underlying this association remain unclear.

To investigate the role of white matter microstructure in the association between body satisfaction and EXD.

Prospective.

One hundred eight regular exercisers (age 22.11 ± 2.62 years; 58 female).

3.0 Tesla; diffusion-weighted echo planar imaging with 30 directions.

The Body Shape Satisfaction (BSS) and Exercise Dependence Scale (EDS); whole-brain tract-based spatial statistics (TBSS) and correlational tractography analyses; average fractional anisotropy (FA) and quantitative anisotropy (QA) values of obtained tracts.

The whole-brain regression model, mediation analysis, and simple slope analysis. P values <0.05 were defined as statistically significant.

The BSS and EDS scores were 37.33 ± 6.32 and 68.22 ± 13.88, respectively. TBSS showed negative correlations between EDS and FA values in the bilateral corticospinal tract (CST, r = -0.41), right cingulum (r = -0.41), and left superior thalamic radiation (STR, r = -0.50). Correlational tractography showed negative associations between EDS and QA values of the left inferior frontal occipital fasciculus (r = -0.35), STR (r = -0.42), CST (r = -0.31), and right cingulum (r = -0.28). The FA values, rather than QA values, mediated the BSS-EDS association (indirect effects = 0.30). The BSS was significantly associated with the EDS score at both low (β = 1.02) and high (β = 0.43) levels of FA value, while the association was significant only at the high level of QA value (β = 1.26).

EXD was correlated with white matter in frontal-subcortical and sensorimotor networks, and these tracts mediated the body satisfaction-EXD association. White matter microstructure could be a promising neural signature for understanding the underlying neuropsychological mechanisms of EXD.

2 TECHNICAL EFFICACY: Stage 1.