We used to train our kids before trips when they transitioned from strollers to walking the parks. We would go on walks and then gradually extend the walks so they got more used to being on their feet that much. It really helped them. We of course told them if they got tired they had to tell us and we would take a break. They were not the best at telling us when they got tired. Lol. So we would usually take a break every 2 hours or so.