Sedentary behavior and physical activity predicting depressive symptoms in adolescents beyond attributes of health-related physical fitness

Background： Sedentary behavior （SB）, physical activity （PA）, and attributes of physical fitness have been shown to be related to depressive symptoms in adolescents. The purpose of the present study was to investigate whether SB and fitness-producing activity predicted depression in active adolescents over and above gender and fitness attributes. Methods： Participants were 249 adolescents （age： 12.85 ± 0.89 years, mean ± SD） from 3 public middle schools who wore Actical accelerometers to assess their SB and PA. Participants also completed the FITNESSGRAM health-related fitness assessment and a brief depression questionnaire. A 3-step hierarchical regression analysis was conducted with gender and fitness attributes （i.e., body mass index （BMI）, maximal volume oxygen uptake （VO2max）, curlups, and pushups）, moderate- and vigorous-intensity activity, and SB entered in respective steps. Results： Regression analysis indicated activity variables （i.e., moderate- and vigorous-intensity activity） significantly predicted depression （△R^2= 0.12, p 〈 0.01） beyond gender and fitness attributes. Overall, gender, fitness attributes, activity variables, SB explained 31% of the variance in depression. Structure coefficients revealed VO2max （rs= -0.77）, moderate-intensity activity （rs= -0.67）, vigorous-intensity activity （rs = -0.81）, and SB （rs = 0.57） were substantially correlated with the criterion variable; thus, they were the strongest predictors of depression. Conclusion： The findings of the current study indicated SB and PA were both significant predictors of depression; however, sufficient fitness-producing activity and adequate cardiorespiratory fitness may nullify the negative influence of SB on depressive symptoms in active adolescents.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.

The impact of the coronavirus disease 2019 pandemic on physical activity in U.S. children

Background:Daily moderate-to-vigorous physical activity(MVPA)is vital to the physical,mental,and social well-being of children.Early restrictions during the coronavirus disease 2019(COVID-19)pandemic included the closure of schools and physical activity(PA)amenities across the US.This study aimed to examine the impact of the pandemic on the PA and play behavior of U.S.children and to provide evidencebased recommendations to improve their PA.Methods:A cross-sectional,online,parent-reported survey was conducted of children aged 318 years between April and June 2020 to assess light PA and MVPA using a modified Godin Leisure-Time Exercise Questionnaire.Additional items included family/child socioeconomic demographics,child adaptability to the pandemic,and community access.The survey was shared through social media and snowball sampling distribution.Results:Analysis of 1310 surveys indicated child PA scores declined significantly during the pandemic(from 56.6 to 44.6,max 119,p<0.001).Specifically,MVPA score decreased(from 46.7 to 34.7,max 98,p<0.001)while light PA remained the same.Age-based changes were seen in the quantity,variety,and intensity of PA,with the lowest pandemic-related impact seen in preschoolers and the highest in high schoolers(4.7 vs.17.2,p<0.001).Community-based peer PA decreased across all age groups.Conclusion:This study shows decreased PA levels in U.S.children,according to parent reporting,during the COVID-19 pandemic.Recommendations for community leaders,educators,and parents to improve PA in children are provided.With continued spread of COVID-19,these results and recommendations may be imperative to the physical well-being of U.S.children.