Are lower levels of physical activity and self-rated fitness associated with higher levels of psychological distress in Croatian young adults? A cross-sectional study

BACKGROUND: Although previous evidence has shown that physical activity and physical fitness lower the level of psychological distress, little is known of simultaneous associations between of physical activity and physical fitness and with psychological distress, especially in young adults. Therefore, the main purpose of the present study was to explore both separate and simultaneous association between physical activity and physical fitness with psychological distress. METHODS: Participants in this cross-sectional study were 2,100 university students (1,041 men and 1,059 women) chosen from eight faculties in the city of Zagreb. Physical activity, physical fitness and psychological distress were assessed using structured questionnaires. The associations were examined using logistic regression analysis. RESULTS: After adjusting for gender, body-mass index, self-rated health, material status, binge drinking, chronic disease/s and sleep quality, "insufficient" physical activity (OR = 2.60; 95% CI [1.92-3.52]) and "lower" levels of physical fitness (tertile 2; OR = 1.94; 95% CI [1.25-3.01] and tertile 1; OR = 2.59; 95% CI [1.65-4.08]) remained associated with "high" psychological distress. When physical activity and physical fitness were entered simultaneously into the model, "insufficient" physical activity (OR = 2.35; 95% CI [1.72-3.21]) and "lower" levels of physical fitness (tertile 2; OR = 1.77; 95% CI [1.24-2.77] and tertile 1; OR = 2.00; 95% CI [1.26-3.20]) remained associated with "high" psychological distress. CONCLUSION: Our study shows that both "insufficient" physical activity and "lower" levels of physical fitness are associated with "high" psychological distress, even after adjusting for numerous covariates. Therefore, special policies aiming to increase the levels of physical activity and fitness are warranted.