What do I put for activities?

Am I supposed to put only school sponsored activities? I do a lot of random stuff outside of school and I don’t know if it’s worth putting on my application. For example, I work out in the gym and I consider fitness a central part of my identity. Is that worth putting?

Sure, do like this:

GTL 12 hours/week

but I GTL 12 hours/day not 12 hours/week