The combined influence of sedentary behavior and physical activity on cardiorespiratory fitness
PURPOSE: The aim of this study was to analyze the combined influence of objectively measured sedentary behavior and physical activity (PA) on cardiorespiratory fitness (CRF) in 2 506 Portuguese children and adolescents aged 10 to 18 years. METHODS: CRF was assessed with the Fitnessgram 20m shuttle-run test. PA and sedentary behaviour were assessed with accelerometry. Participants were classified as meeting current PA guidelines for youth vs not meeting; and as low vs High sedentary (according to the median value of sedentary time/day by age and gender); and then grouped as follows: Low Active - High Sedentary; Low Active - Low Sedentary; High Active - High Sedentary; High Active - Low Sedentary. Binary logistic regression models were constructed to verify the relationship between high CRF and the combined influence of PA/sedentary behavior, adjusting for age, gender and body mass index. RESULTS: Participants classified as high active/low sedentary (OR=1.849; 95%CI:1.246-2.744), as well as those classified as low active/low sedentary (OR=1.297; 95%CI:1.034-1.626) were more likely to be fit, compared with those from the low active/high sedentary group. CONCLUSIONS: These findings suggest that PA levels may not overcome the deleterious influence of high sedentary time. Our data stress the importance of promoting PA and discouraging sedentary behavior.
Santos, R. M., Pratt, M., Okely, A. D., Mota, J., Moreira, C., Coelho-E-Silva, M. J., Vale, S. & Sardinha, L. B. (2012). The combined influence of sedentary behavior and physical activity on cardiorespiratory fitness. Medicine And Science In Sports And Exercise, 44 (Supplement 2), 920-920.