Judo is a way of life. My father who started KBI as a branch of Kokushikan university 50 years ago is 75 years old. He is in excellent shape. He taught me that Judo is forever. Why? Let me tell you... The merits of the sport are apparent. Not only does it promote growth in physical aspects (strength, speed, etc), but it also helps the mind flourish. Jigoro Kano developed judo as an education system that encompasses all areas of life. Many sports has the sole mission to build the athlete to acquire a certain skill set and to excel within the realm of the sport itself. However, Judo helps you to become a better citizen of the world.
I believe humans are supposed to reach out and grab someone. To fight, grapple and play. Throw, trip and wrestle. The fight or flight is the most primitive of human responses and I believe Judo training caters to this human need. In the modern tech age, we spend most of our days staring into a glowing rectangle, hunched over our artificial communication centers. Couped up in our 9-5's. Even the food we eat is processed to a point where there aren't any remnants of what nature originally intended for us to consume.
In a world like this, no wonder people fall into the depths of dark psychological abyss. Although I know I am biased through the childhood indoctrination, I believe judo is the Panacea to this pandemic. Throw a gi on, reach out, Grab someone and fight them! But not JUST fight... BUT The way Jigoro kano meant for it to be... In congruence with an education system that develops the mind, body and soul.
Here is a thread about Judo and longevity. Enjoy.