Buongiorno,
Not much of a runner myself - but I do love to walk and one of my favorite walks in Florence when I just want a bit of peace is along the Arno River.
I have attached a link that has a map - - the red trail is way too long (45km), but there are pieces of it that might strike a chord with you in the city and along the river:
http://www.firenzeurbantrail.com/it/.../percorso.html
Buon Viaggio,
Donna Denise
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