I've been trying to pick up the pace a bit on outings less than an hour, inserting periodic bursts of speed ['speed' here very much a relative term] in the middle or near the end of the run. Some mornings it has been a few hundred metres or so, others as much as a 4km 'time-trial'. This morning it was 1000 meters, kilometer nine of a twelve kilometer run, in 3.43. As it was nip and tuck as to whether my heart would explode before my hamstrings snapped, I was given a very visceral reminder that I am not built for speed.
The 100km run is now only 31 days away.