Submariner Loses Time When Worn But Not In Winder Or Off Wrist

[Doug13]

I own a three year old Submariner that was purchased new. Up until recently it has kept reasonably good time for a Rolex. Just the usual few seconds slow each day. About a month ago it started losing time whenever I wear it. It is worse when I wear it while running when it loses approx 10 minuets in a 25 minuet time span! If the watch is placed in my watch winder it keeps perfect time or if it is simply taken off and placed on a table. I am completely baffled by this. Any suggestions or ideas on why this is happening?