The challenge is to run as many of standard loops in Central Park as possible in a day. You can start/finish at any point on the standard Central Park Main Road. The Central Park Authority puts this loop at 6.1 miles. Central Park is open from 6am to 1am. To make sure that you are not cheating and entering the park before it opens, or leave after the park is closed, the official challenge starts at 6:05am and goes to 12:55am. The challenge is for whole laps only. If you match the number of laps of the previous FKT, you must have a faster time, so be sure to report your actual start and finish times.
