Sports club and volunteering are neither restorative nor relax. Sports are another competitive activity you are supposed to excel at. You dont do it to rest and relax.

You come in and do what you are told. You don't chat with friends or play around, you focus on whatever trainer told you to focus at. You dont do what you want to do, but what trainer thinks will make you more performant. And if it hurts or you are tired or just really want to do something else, you still do it.