2nd day in NB855

today is 2nd day with NB 855 and heart beat strap across my chest. Start my warmup from cp to startpoint 400m. A cool 1.4km walk with avg HB of 117, and then start the run, sored thighs were felt during warmup and slight aching calves too. Started the 1st 400m slowly, at 60 sec per 100m pace, pushing up and down the 7 damn slopes and perspiration soon filled my face at last slop at 1.5km, hitting the heart beat to 150. On the flat stretch , i started to hold my regular breathing and maintain a good rhythm and gearing up the heart beat to 160s, and final 400m , i push to 170 at 90 over%. Good breathing and finished the run with 20 min 31 sec. Cool down by walking and catching my breathe and brought the HB down to 139, at 75%. Maintain the 139 all the back back to CP, and pretty much exhausted after a good 80 min workout. Thighs ached even more and calves too