Central Park features about 100k of hiking and running paths. Technically, the southernmost tip of Central Park is located in Töölönlahti Bay but the actual gateway to the park is located north from the Olympic Stadium.
Paloheinä — located at northernmost part of Central Park, around 8 miles from downtown — is probably the best area for running. Paloheinä offers sawdust running trails in a beautiful agricultural landscape. Note that in winter season, some of the trails are kept clean from snow while other are used for skiing, thus not suitable for running.Info on Paloheinä Info on Central Park