Use It Or Lose It.
Watch the 75 year old man showing his physical prowess in the streets of Germany. As Ross states in his blog, Walter Perfahl is not a former gymnast or a circus performer, as we all can assume him to be so. He was a former miner, who has been physically active. He also recommends the importance of physical fitness while he performs at his shows.
If you want to be physically fit and enjoy radiant health even as you age, you have to exercise regularly. You cannot get away by performing some easy and lazy drill. You have to bust your ass, so to speak.
Enjoy the Video.