Table 1.

Focus group semi-structured question guide

Question type	Question
Opening	1. What is your name; how many grandchildren do you have; what is the name, sex and age of your grandchild(ren)?
Key questions	2. If you think about the period before measures were taken against COVID-19, were you more / less physically active while caring for your grandchild(ren) compared to when not providing care for your grandchild(ren)? a. Which factors influenced your PA when (not) providing care for your grandchild(ren)?
	3. If you think about the period before measures were taken against COVID-19, were you more / less sedentary while caring for your grandchild(ren) compared to when not providing care for your grandchild(ren)? a. Which factors influenced your SB when (not) providing care for your grandchild(ren)?
	4. If you think about the period before measures were taken against COVID-19, during which activities were you mainly physically active? a. Were you mainly physically active together with your grandchild(ren)? Why / why not?
	5. If you think about the period before measures were taken against COVID-19, during which activities were you mainly sedentary? a. Were you mainly sedentary together with your grandchild(ren)? Why / why not?
	6. If you think about the period before measures were taken against COVID-19, to what extent did caring for your grandchild(ren) take priority over other activities (organized or not) in your daily life?
Closing	7. Do you have any further remarks, suggestions, additions?

PA physical activity, SB sedentary behavior