The only thing that approaches it is in BJJ tourneys where there is usually a "Masters" or "Executive" division for people 40 or 50+. And it's there because people know that even though someone might be a brown belt in BJJ at 55, they can't compete with a brown belt at 25, just based on sheer physicality. Whereas in Aikido, somehow the older you are...the better you get at it?
I must object! Having just "graduated" to the Executive division, this attitude just grinds my gears. If I didn't think I had the physicality to compete, I wouldn't have entered the tourney in the first place.
Its not that I mind that there are age divisions per se, but its the way tourneys are usually run: Say if there are not enough belts in the executive 180lb division, that division gets combined with the executive 195lb division. I would rather compete with the 25 yr old 180lb division. IMO the age/physicality advantage of the younger guy is less than the weight advantage of the heavier guy.
Or maybe I'm just in great shape for an old fart.