(medium) long and a measurement... (Update)

Today I did another medium long run: 27.5km. Used only one bottle of water because the temperature was just around 16-18 C. Average pace was 4:50min/km and heart rate was 135 bpm. My Marathon pace heart rate should be around 160 bpm according to a fitness test I did some years ago. Checked my long runs in November 2008: I ran 32km @ 4:25 min/km with an average heart rate of 139 bpm. Finished Ohtawara Marathon in 2:53...