The Long Island Greenbelt Trail runs about 32 miles from Heckscher State Park to Sunken Meadow State Park. Evolution of the FKT is documented on the old site. Barney Fortunato ran this 32-mile route a couple of times with a best time of 4h41m15s on July 25, 2015. Others have run it, but we know of no faster completion.
Here's a link to the Long Island Green Belt Trail Conference (maps & information).
Hiked many times hard part is despite being in and urban area there is limited places to get water
On Saturday, April 20th they are holding the first "Shore 2 Shore" race on the trail. The course will differ slightly from the marked trail at the start and end but overall I think it will still work out to around 50 km. There will be several aid stations so I would say that the time for the winner on Saturday would qualify as the supported FKT for both Male and Female. Good luck to all.