There is someone who lives at the intersection of exercise and numismatics!
The "Happy Runner" hides elongated coins as he runs, bikes, hikes, and walks around. These coins include his website, claimthisfind.com where folks like me who find his pieces can report on their finds (full disclosure I have nothing to do with this website).
Here is the elongated coin (host: Croatian 1993 5 Kuna) that I found recently in San Diego:
Most of the recent finds seem to have been in Southern California.