1hour 45mins of running. Not non-stop but as in going out on a run. It was a beautiful day and all the conditions were right, I felt full of energy ETC.!
Longest I've exercised as in walking is probably about 9 hours! A not-especially-speedy ascent and descent of Snowdon.
I used to have 2/3 hour walks when I lived in the countryside with one particular friend. And in Squad I would swim for a couple of hours sometimes, although that's intermittent. These days if I do two hours of exercise it's because I have training and then a match straight afterwards (netball).
When I was a teen I would go skateboarding with my mates every day, and at the weekends we'd normally head out about 9 in the morning and be out until about midnight. We'd either be skating or walking to another spot which at times might have been over half an hour's walk. We'd pretty much only rest for food.
Wish I had that kind of relentless energy nowadays...