Everything I've read on the subject suggests that increased exercise would decrease your INR, due to increased metabolism. This effectively means your blood pumping around your body more which means its getting filtered through your liver. This filters out the warfarin. Similarly it would seem that INR would be effected by all the things I work on to do with my metabolism and health. Heat, hormones, thyroid, illness and diet all effect INR levels. My diet is pro thyroid (metabolism) I'm always super hot and I'm always eating to support a super efficient metabolism. It seems like my diet is an antiwarfarin diet. Fruits like mangoes, melons, OJ, lemons etc all work to keep me with a healthy metabolism and seem to fast forward the warfarin right out of my body.
Somehow I cant see myself giving up my nutrients and thyroid health just to allow my blood to thin. That seems like deliberately getting sick to help my INR reading. Overall health matters more I'm afraid.