A friend and fellow window cleaner is 68 years old. He's fit as a fiddle, though reduced his round down to those houses that are easy to do (no climbing over gates, garages and don't require A Frames for the downstairs houses).
He looks and acts a lot younger and blames it on window cleaning.
I'm 33 and feel old and decrepid!
Hope it improves when I'm 68!
Tosh (windows-chepstow).