Fig. 1

Example of one participant’s profile for one day of VM counts/minute within ordered sitting bouts. Vertical grey lines indicated all possible sitting bout lengths from 1 minute to 60 minutes. The corresponding horizontal axis at bottom was the cumulative sum of the top bout lengths and the maximum value of the bottom axis was \(\sum _{b=1}^{60}b=1830\) minutes, which implied \(t\in [1,1830]\) with increment of 1 minute. t = 1 at the bottom was mapping to 1-minute sitting bout at the top; t = 2 and 3 at bottom were mapping to the first minute and second minute of the 2-minute sitting bout at the top; t = 4 to 6 at the bottom would be the 3-minute bout at the top, etc. If the top bout length was 8 minutes, the corresponding bottom values would span from \(\sum _{b=1}^7 b = 28\) to \(\sum _{b=1}^8 b = 36\); if the top bout length was 60 minutes, the bottom values would span from \(\sum _{b=1}^{59} b = 1770\) to 1830. Each minute of the bottom axis held a VM count value or a missing value. Black dots represent VM counts/minute within sitting bouts