The map of the Epcot Resort area shows a running path on the road between the Beach Club and the Boardwalk (where the road goes under the waterway), but I wouldn't recommend it - there's no sidewalk there, and you end up running on the roadway itself, which is rather narrow. Lots of buses and traffic going through there, and I felt pretty exposed - I only did it once, and now I just cut through the Beach Club and take the path between the hotel and the villas, then the small sidewalk around the edge of the hotel (the side closest to Epcot) which joins up with the main walkway around Crescent Lake.