Sleep quality and body composition in active and inactive young adults

Body composition is influenced by a variety of internal and external factors, with early adulthood being a particularly sensitive period for its fluctuations. This observational study aimed to assess the differences in body composition, anthropometric indices, and sleep quality between active and inactive young adults as well as to explore the relationship between these parameters. A group of one hundred young adults were recruited for the study and assigned to two groups: physically active and physically inactive. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ-SF), sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), and body composition was measured using the validated InBody 770 analyzer. Participants were classified as physically active if they achieved a "moderate" or "high" activity level according to IPAQ-SF scoring criteria, which includes individuals engaging in at least 600 MET-minutes of physical activity per week. Those categorized as physically inactive scored at the "low" level, not meeting the thresholds for moderate or high activity. Physically active individuals showed significantly more favorable body composition, including higher total body water, muscle mass, and bone mineral content, as well as lower fat mass, BMI, WHR, WHtR, and ABSI values (all p < 0.001). They also had significantly better sleep quality, as indicated by lower Global Sleep Score (GSS) scores (p < 0.001). Significant associations were observed between sleep quality and body composition parameters, such as a positive correlation between the GSS and fat mass, as well as negative correlations between GSS and total body water, fat-free mass, and bone mineral content. Additionally, GSS showed positive correlations with both WHR and WHtR (p < 0.05). No significant associations were found between the GSS and muscle mass, nor between GSS and ABSI (p > 0.05). These findings suggest that regular physical activity is related to more favorable body composition and better sleep quality. Moreover, specific components of body composition, particularly fat mass and indicators of central adiposity, appear to be significantly associated with sleep quality, highlighting a potential link between metabolic health and sleep patterns. However, due to the cross-sectional nature of the study, causality cannot be inferred.