Does anyone know of any videos of any of the old great players such as Morten Frost playing nowadays? It doesn't have to be particularly competitive, it'd just be interesting to see how well they fare/how far their standard has dropped. I recall seeing a video of a Chinese MS player doing lots of backhand clears versus a guy doing forehand clears and after about 50 shots the forehand guy makes a mistake.
Arguably you could say Taufik now as he's an "old man" but that's just sad.
I'd pay good money to see Park Joo Bong/Kim Moon Soo play now. Are there any videos of the pair playing after their retirement? I know they separated quite soon after, but there may have been some exhibition matches?
In tennis they have a seniors tour, wish they did the same for badminton.
The major decline of these guys is their leg strength. Take Chen Hong as an example. His anticipation and racket skill remain superb. The elevation of his jump used to be remarkable, but now probably due to lack of training and ageing he barely jumps off the floor and moves much more slowly.
Explosive strength does indeed decline with age, but you can maintain pure power strength for quite a while. (Thus all those middle-aged cycling dudes I see on the roads here).
I would vote for back flexibility as one of the other fastest declining feature of aging sports heroes. It keeps you from being able to twist, turn, flex and extend the way one used to do. One starts to rely on the pure strength of the arm (as well as experienced guile) to win points.
BTW Chen Hong may not have moved in that video as well as in the old days, but he sure demonstrated some mighty backhand strength!