THE BOTTOM LINE

The new rule governing the layout of marathon courses won’t affect records that have already been set in the most renowned race of them all, the Boston Marathon. “It’s not retroactive,” said national records Chairman Basil Honikman of The Athletics Congress. He said Alberto Salazar’s 1982 Boston run of 2 hours, 8 minutes, 51 seconds will remain on the books as the American point-to-point marathon record. Under the new rule, the starting line can be no more than 1 meter per kilometer--about 42 meters for a marathon--higher in altitude than the finish line.