Tapering is when you reduce the volume and intensity of runs in your marathon training to allow your body to adapt and recover, and crucially to be fresh and ready enough to run the marathon itself,” says Anderson. “The biggest difference when tapering is the reduction in your long run, which starts about three to four weeks before the race—at that point consider cutting your long run back to a maximum of 2½ hours. At two weeks cut it to two hours, and at one week do a relaxed 75-minute run.