Aristides M Machado-Rodrigues1, Manuel J Coelho E Silva2, Luís P Ribeiro3, Romulo Fernandes4, Jorge Mota5, Robert M Malina6,7. 1. Research Centre for Sport and Physical Activity, Universidade de Coimbra, Escola Superior de Educação de Viseu, Rua Dr. Maximiano Aragão, 3504-501, Viseu, Portugal. rodriguesari@hotmail.com. 2. Faculdade de Ciências do Desporto e Educação Física, Universidade de Coimbra, Estádio Universitário Coimbra Pavilhão-III, 3040-156 Coimbra, Portugal. mjcesilva@fcdef.uc.pt. 3. Departamento de Educação Física/Department of Physical Education, Faculdade de Ciências e Tecnologia/Center of Science and Technology, Universidade Estadual Paulista - UNESP, Presidente Prudente, São Paulo, Brazil. romulo_ef@yahoo.com.br. 4. Faculdade de Ciências do Desporto e Educação Física, Universidade de Coimbra, Estádio Universitário Coimbra Pavilhão-III, 3040-156 Coimbra, Portugal. lpribeiro@ualg.pt. 5. Research Centre in Physical Activity, Health and Leisure, Faculty of Sport Sciences, University of Porto, R. Dr. Plácido Costa, 91, 4200-450 Porto, Portugal. jmota@fade.up.pt. 6. Department of Kinesiology and Health Education, University of Texas, Austin, TX. rmalina@1skyconnect.net. 7. Department of Kinesiology, Tarleton State University, Stephenville, 10735 FM 2668, Bay City, TX 77414. rmalina@1skyconnect.net.
Abstract
BACKGROUND: Research on relationships between lifestyle behaviors and adiposity in school youth is potentially important for identifying subgroups at risk. This study evaluates the associations between waist circumference (WC) and objective measures of sedentary behavior (SB) in a sample of rural school adolescents. METHODS: The sample included 254 students (114 boys, 140 girls), 13-16 years of age, from rural regions of the Portuguese midlands. Height, weight, and WC were measured. Cardiorespiratory fitness (CRF) was assessed with the 20-m shuttle-run test. An uniaxial GT1M accelerometer was used to obtain 5 consecutive days of physically activity (PA) and SB. Multiple linear regression was used to test associations between WC and SB, adjusted for several potential confounders (age, sex, PA, CRF, parental education). RESULTS: SB was not significantly associated with the WC, neither in the unadjusted model nor after adjustment for all potential confounders. In the final model, the unique significant predictor of the WC was cardiorespiratory fitness (β = -0.82; 95% confidence interval [CI], -1.02 to -0.62). CONCLUSION: WC was not independently associated with SB time in rural school adolescents. Future research is claimed among rural adolescents in different geographic contexts to try to clarify recent findings of less studied communities.
BACKGROUND: Research on relationships between lifestyle behaviors and adiposity in school youth is potentially important for identifying subgroups at risk. This study evaluates the associations between waist circumference (WC) and objective measures of sedentary behavior (SB) in a sample of rural school adolescents. METHODS: The sample included 254 students (114 boys, 140 girls), 13-16 years of age, from rural regions of the Portuguese midlands. Height, weight, and WC were measured. Cardiorespiratory fitness (CRF) was assessed with the 20-m shuttle-run test. An uniaxial GT1M accelerometer was used to obtain 5 consecutive days of physically activity (PA) and SB. Multiple linear regression was used to test associations between WC and SB, adjusted for several potential confounders (age, sex, PA, CRF, parental education). RESULTS: SB was not significantly associated with the WC, neither in the unadjusted model nor after adjustment for all potential confounders. In the final model, the unique significant predictor of the WC was cardiorespiratory fitness (β = -0.82; 95% confidence interval [CI], -1.02 to -0.62). CONCLUSION: WC was not independently associated with SB time in rural school adolescents. Future research is claimed among rural adolescents in different geographic contexts to try to clarify recent findings of less studied communities.