Ballack started working with Athletes Performance when Jurgen Klinsmann introduced the high-performance company after becoming German boss in 2004
And American sports scientist Michael Verstegen said: "One of the things we can do is to prolong to the life a player - make the 'sweet spot' of his career last so much longer.
"Eighteen months ago, Ballack looked like he might have gone beyond that sweet spot, but no longer.
"If he keeps working as we know he is now doing he can maintain that fantastic level he has finally reached in the English game for a long time to come yet."
Ballack believes the American has got it right. He said: "I'm still young at 32. I'm enjoying playing.
"I want to play football for a few more years at a high level because I feel good - I have years left in me yet."