Muscular fitness, body composition and physical self-perception in adolescents.

The primary aim of this study was to investigate gender differences in the relationship between muscular strength, body composition, and physical self-perception in adolescents. Participants (n=106, age 15.0±0.7 years, 51% boys) completed the following assessments: height and weight, bio-electrical impedance analysis (body fat %), muscular strength (1RM bench press and leg press), and the Children's Physical Self-Perception Profile. Bivariate correlations were examined and mediation analysis was used to explore if physical self-perception sub-domains mediated the relationship between muscular strength/adiposity and overall physical self-worth. Among boys, physical self-worth was associated with absolute total strength (r=0.36, p<0.01), but not with body fat % (r=-0.11, p=0.44), or relative total strength (r=0.21, p=0.13). In adolescent girls, physical self-worth was associated with body fat % (r=-0.42, p<0.01), relative total strength (r=0.40, p<0.01) but not absolute total strength (r=0.07, p=0.62). In boys, perceived physical strength mediated the relationship between absolute muscular strength and physical self-worth. Relative muscular strength was not associated with perceived strength (p>0.05) in girls and the test of the mediated effect was non-significant (p>0.05). Perceived body attractiveness was found to mediate the relationship between body fat % and physical self-worth among boys and girls. Physical self-worth is associated with different components of health-related fitness in adolescent girls and boys. Mediation analysis can be used to provide insights into the complex interrelationships between variables.