Ever since I've been on widowhood, my pigeons have NEVER flown for an hour just raced around home for 15-20 minutes. If you live on an estate of sorts, it's difficult to get your birds to fly and flagging them only pushes them to the housetops. If you're fortunate enough to live in the wide open spaces, they will exercise naturally.
I remember a champion pigeon called " FIREFLY " his owner ( a friend of mine ) told me that EVERY day when the cocks were let out, FIREFLY would go straight to the TV arial and never move until the other cocks came in. Put him in the basket at week ends, nothing to touch him. Just showing that all pigeons are individuals.