The bold sedentary behavior recommendations in the new Canadian guidelines: are they evidence-based? Response to “Sedentary Behavior Research Network members support new Canadian 24-Hour Movement Guideline recommendations”

Dear editor,We read with interest the commentary by Mark Tremblay and colleagues,1 which outlines the new 24-Hour Canadian sedentary behavior guidelines.These guidelines take the perspective of a continuum across the 24-h day,providing a vehicle for discussing physically active time,sitting and other sedentary time,as well as healthy sleep duration.The commentary 1 focuses on the sedentary behavior(SB)recommendations in these guidelines:(1)limiting sedentary time to8 h per day,(2)limiting recreational screen time to3 h,and(3)breaking up long periods of sitting as often as possible throughout the day.Support for this perspective was evidenced by a survey of a sample(n=126,6% of total)of Sedentary Behavior Research Network(SBRN)members2 indicating broad acceptance of these SB recommendations.1 In this response,we put this survey in context and discuss the evidence base underpinning these 3 Canadian sedentary-behavior recommendations.