In America, there are sometimes competitions for the longest piano playing or the longest dance marathon. There have been people who danced for four consecutive days without stopping, all in pursuit of a dubious title. It’s hard to say if there was ever a competition for standing on one’s feet, but if there was, the winner still wouldn’t be able to claim the top prize.
In nature, there are living beings that likely hold the record for standing on their feet the longest: elephants. No one has ever seen an adult African elephant lie down. When resting, it sometimes leans its tusks against a tree trunk or rests them on the lower branches of a tree.
Thus, throughout its life—around a hundred years—an elephant remains on its feet.