Before we moved to Lancashire in 1974 there was something we did at least once, even in the week long holidays, and many more times during the longer holidays.
When we were too young to stop home on our own we would go to our Grandma's for the week. Mum's Mum one week, Dad's Mum the next.
To give Grandma a little bit of a break, at least once a week we would go swimming. Mum worked in Glossop so would take us and drop us by Woods baths, which I believe are still there. We would swim until our numbers were called, then get out. After getting dressed again, and maybe having a hot chocolate if we had some change for one, we would set off back to Grandma's house. It never seemed to rain, or perhaps we didn't care. We would walk home from the baths, a distance of at least 3 miles, further to our Grandma on Dad's side. The walk wasn't a relatively flat one as many are in this part of Lancashire, but one of hills. Like I said, we would do this at least once, sometimes twice a week.
These days parents worry abut their children meeting with untrustworthy characters, and therefore do not let them do things like this. Perhaps that is a contributory factor as to why more children these days are overweight.