BACKGROUND: The aims of this study were to examine what amount of sedentary time is associated with low cardiorespiratory fitness (CRF) in adolescents and whether this association is independent of physical activity. METHODS: The study comprised 1808 adolescents aged 12.5-17.5 years from 10 European cities. Sedentary time and moderate-to-vigorous physical activity (MVPA) were measured by accelerometer. CRF was assessed by the 20 m shuttle-run test. Adolescents were divided into two groups (high/low) according to FITNESSGRAM guidelines. Receiver-operating characteristic (ROC) analysis was used to determine thresholds that best discriminate between high and low CRF in adolescents. RESULTS: Adolescent girls had more sedentary time than boys (p<0.001). ROC analysis showed that girls spending ≥69% of waking time in sedentary activities had low CRF, but no significant threshold discriminated between high and low CRF in boys. Adolescent girls who exceeded this threshold had lower levels of CRF (p≤0.001) and were more likely to have a low CRF (OR 1.68, 95% CI 1.22 to 2.31) independent of centre, age and body mass index. The negative influence of excessive sedentary time on CRF remained significant (p=0.045) in adolescent girls who did not meet the physical activity guidelines (<60 min/day in MVPA) but was abolished (p>0.05) in those who met the recommendation (≥60 min/day in MVPA). CONCLUSION: Excessive sedentary time is associated with low CRF in adolescent girls but not in boys. However, this adverse effect might be attenuated if adolescent girls meet the current physical activity guidelines.
BACKGROUND: The aims of this study were to examine what amount of sedentary time is associated with low cardiorespiratory fitness (CRF) in adolescents and whether this association is independent of physical activity. METHODS: The study comprised 1808 adolescents aged 12.5-17.5 years from 10 European cities. Sedentary time and moderate-to-vigorous physical activity (MVPA) were measured by accelerometer. CRF was assessed by the 20 m shuttle-run test. Adolescents were divided into two groups (high/low) according to FITNESSGRAM guidelines. Receiver-operating characteristic (ROC) analysis was used to determine thresholds that best discriminate between high and low CRF in adolescents. RESULTS: Adolescent girls had more sedentary time than boys (p<0.001). ROC analysis showed that girls spending ≥69% of waking time in sedentary activities had low CRF, but no significant threshold discriminated between high and low CRF in boys. Adolescent girls who exceeded this threshold had lower levels of CRF (p≤0.001) and were more likely to have a low CRF (OR 1.68, 95% CI 1.22 to 2.31) independent of centre, age and body mass index. The negative influence of excessive sedentary time on CRF remained significant (p=0.045) in adolescent girls who did not meet the physical activity guidelines (<60 min/day in MVPA) but was abolished (p>0.05) in those who met the recommendation (≥60 min/day in MVPA). CONCLUSION: Excessive sedentary time is associated with low CRF in adolescent girls but not in boys. However, this adverse effect might be attenuated if adolescent girls meet the current physical activity guidelines.
Authors: Augusto César Ferreira de Moraes; Heráclito Barbosa Carvalho; Juan Pablo Rey-López; Luis Gracia-Marco; Laurent Beghin; Anthony Kafatos; David Jiménez-Pavón; Dénes Molnar; Stefaan De Henauw; Yannis Manios; Kurt Widhalm; Jonatan R Ruiz; Francisco B Ortega; Michael Sjöström; Angela Polito; Raquel Pedrero-Chamizo; Ascensión Marcos; Frederic Gottrand; Luis A Moreno Journal: PLoS One Date: 2013-05-01 Impact factor: 3.240
Authors: Iris F Groeneveld; Elena S Sosa; Margarita Pérez; Carmen Fiuza-Luces; Laura Gonzalez-Saiz; Cristian Gallardo; Luis M López-Mojares; Jonatan R Ruiz; Alejandro Lucia Journal: Qual Life Res Date: 2012-01-05 Impact factor: 4.147
Authors: Friederike Stölzel; Nadja Seidel; Stefan Uhmann; Michael Baumann; Hendrik Berth; Jürgen Hoyer; Gerhard Ehninger Journal: BMC Public Health Date: 2014-04-23 Impact factor: 3.295
Authors: Carmen Peiró-Velert; Alexandra Valencia-Peris; Luis M González; Xavier García-Massó; Pilar Serra-Añó; José Devís-Devís Journal: PLoS One Date: 2014-06-18 Impact factor: 3.240