Body fat, but not muscle quality, is related to perceived fatigue in young-adult active and inactive women

The purpose of this study was to investigate the association of perceived fatigue with body composition and muscle quality (strength, thickness and specific torque) in young adult women. Fifty-one healthy women (31.98 ± 6.88 years) were assessed regarding perceived fatigue, body composition, knee extensors muscle strength, muscle thickness, and muscle quality. The short version of International Physical Activity Questionnaire was applied to classify subjects as active or inactive. To examine the relationship between perceived fatigue and dependent variables, the Pearson’s correlation was performed. Perceived fatigue was significantly correlated (p < 0.05) with body weight (r = 0.469), body mass index (r = 0.369), fat mass (r = 0.469), percent body fat (r = 0.396), and relative peak torque (r = -0.378). Additionally, inactive women had significantly greater (p < 0.05) body weight, body mass index, fat mass, percent body fat, and perceived fatigue than active women. Perceived fatigue is related to body weight and fat mass, but not to muscle strength or muscle quality. Moreover, physically active women showed lower perceived fatigue, body weight, and body fat compared to physically inactive women. These results suggest that body fat may play a role in perceived fatigue and physical activity could attenuate such symptom.