My husband was a runner in his teens Then dropped it until his mid 30s when he started vey serious running competing in marathons quite reqularly.P.D was diagnosed at 61.which is two and a half years ago.At present his only real symptom is tremor and drooling:he still runs but in the gym(The instructor thinks he is improving)Still plays a squeeze box for at least an hour a day which exercises his fingers. Still sings and calls dances, usually without a mike.Still Morris dances(You know men in white with bells and hankies )I mention all this as I wonder how he would be if he did not exercise.AND when did the P.D strike originally ?Was it during his inactive period during his 20s?He certainly had a tremor in his foot when excited ,annoyed or angry for at least 25 years before P.D was diagnosed formally.OR was he just one of the unlucky ones that just got P.D anyway? I suppose we will never know.He has now started using the bicycle!!!