Interesting looking at the Strava group just now. Of the eight of us on there who've been out we've all done pretty similar distances of between 5 and 6.7 k. Mine is by far the slowest. Dawdled round 5k in about 27.30 just to get the stiffness out of my legs but coming home in to a stiff breeze took much more effort than I was expecting and I jog / walked an extra k to cool down and see if it helped my legs. Jury's out right now.