Objectively measured sedentary behaviour and cardio-metabolic risk in youth: a review of evidence

The aim of this paper was to review studies that examine the association between volume and pattern of objectively measured sedentary behaviour and markers of cardio-metabolic risk in youth. A search for relevant articles was conducted in PubMed and SportDiscus, and the following inclusion criteria were applied: (i) youth participants (age range 6-19); (ii) accelerometer-measured volume and/or pattern of sedentary behaviour and its association with a parts per thousand yen1 cardio-metabolic outcome; and (iii) published, in press or accepted in an English language peer-reviewed journal between January 2000 and October 2013. A total of 45 articles met the a priori criteria and, thus, were considered eligible for inclusion. Although youth accumulate approximately 6 to 8 h of daily sedentary behaviour, little evidence supports an association with individual and clustered cardio-metabolic risk when adjusted for moderate-to-vigorous physical activity (MVPA). Conclusion: We suggest that youth should be encouraged to engage in recommended levels of MVPA and reduce excessive time spent in screen-based sedentary behaviour. Future studies should examine the association between volume and pattern of objectively measured sedentary behaviour and cardio-metabolic risk independent of time spent in MVPA.