I feel like going for a bike ride now.
In our city, it borders a coast. Along that coast there is a walkway. One day, me and a friend sprinted:
From our house at one end to the other end
Back 90% of the way to our house, thinking that mum forgot to pick us up
She txt'd so we turned round and went back to where she was going to pick us up
Decided to go back again, so went back to my house, then way back to where mum was
All this was going super-fast on bikes, no calm strolling. Each way is about 6-8km, that's about 4 miles. We traveled about 20 miles that day, and I was shattered for a week, not to mention sunburnt.