The Evolving Definition of "Sedentary"

Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA.
Exercise and sport sciences reviews (Impact Factor: 4.82). 11/2008; 36(4):173-8. DOI: 10.1097/JES.0b013e3181877d1a
Source: PubMed

ABSTRACT Studies that did not directly measure sedentary behavior often have been used to draw conclusions about the health effects of sedentariness. Future claims about the effects of sedentary, light, and moderate-to-vigorous activities on health outcomes should be supported by data from studies in which all levels of physical activity are differentiated clearly and measured independently.

Download full-text


Available from: Felipe Lobelo, Mar 13, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The presented systematic review aims at giving a comprehensive overview of studies assessing the relationship between sedentary behavior and indicators of mental health in school-aged children and adolescents. Six online databases (MEDLINE, EMBASE, PsycINFO, PsycARTICLES, CINAHL and SPORTDiscus) as well as personal libraries and reference lists of existing literature were searched for eligible studies. Ninety-one studies met all inclusion criteria. There was strong evidence that high levels of screen time were associated with more hyperactivity/inattention problems and internalizing problems as well as with less psychological well-being and perceived quality of life. Concerning depressive symptoms, self-esteem, eating disorder symptoms, and anxiety symptoms, no clear conclusion could be drawn. But, taking quality assessment into account, self-esteem was negatively associated with sedentary behavior, i.e. high levels of time engaging in screen-based sedentary behavior were linked to lower scores in self-esteem. Overall, the association between sedentary behavior and mental health indicators was rather indeterminate. Future studies of high quality and with an objective measure of sedentary behavior will be necessary to further examine this association as well as to investigate longitudinal relationships and the direction of causality. Furthermore, more studies are needed to identify moderating and mediating variables. Copyright © 2015. Published by Elsevier Inc.
    Preventive Medicine 04/2015; 76. DOI:10.1016/j.ypmed.2015.03.026 · 2.93 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Low physical activity and high sedentary behaviour levels are major concerns in persons with multiple sclerosis (MS) and these differ depending on the level of mobility disability. However, the manner in which daily activity is accumulated is currently unknown in this population. Methods: A secondary analysis was performed on a combined data set of persons with MS from two previous investigations of physical activity and symptomatic or quality of life outcomes in the United States over a two year period (2007-2009). Mobility disability status was determined using the Patient Determined Disease Steps (PDDS) while activity behaviour was objectively monitored using ActiGraph accelerometer for 7 days. Results: Persons with MS who have mobility disability were involved in sedentary behaviour, light and moderate intensity activity for 65%, 34% and 1% of the day, respectively compared to 60%, 37%, and 3%, respectively in those without mobility disability (p < 0.05). Breaks in sedentary time did not differ by mobility disability status. Compared to those without mobility disability, the average number of sedentary bouts longer than 30 minutes was greater in those with mobility disability (p= 0.016). Conclusion: Persons with MS with mobility disability are less active, engage in more sedentary behaviour and accumulate prolonged sedentary bouts.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, the association between physical activity and other potential determinants, objectively measured by accelerometry, was examined. Sixty-two men attending an infertility clinic participated in the study. Obese men (body mass index ≥ 30) and those with a waist circumference 102 cm or more had lower semen volume than the other men (P < 0.05). Higher values in sperm parameters were observed in participants who completed university studies and those who did not consume snuff, compared with the other participants (P < 0.05). Finally, men who spent an average number of 10 min-bouts of moderate-to-vigorous physical activity had significantly better semen quality than those who engaged in low or high numbers of bouts of activity (P < 0.05). No associations were found for sedentary or moderate-to-vigorous physical activity time when it was not sustained over 10 min, i.e. not in bouts. Men who have average levels of physical activity over sustained periods of 10 min are likely to have better semen quality than men who engage in low or high levels of such activity. Similarly, high levels of total and central adiposity, low educational level and snuff consumption are negatively related to semen quality. Copyright © 2015 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.
    Reproductive biomedicine online 03/2015; DOI:10.1016/j.rbmo.2015.03.004 · 2.98 Impact Factor