steady run for 12km with heart beat

When I went for trail run with one of Namban crew Jay last Saturday, my maximum heart rate was higher 205. Then I had heart sore. I couldn't take a breath, either walk. Just took a deep breath quietly. I thought perhaps I could die suddenly on the top of mountain.

Tonight, I had a running plan by Steve: Steady for 12k, if I'm tired just run a whole distance at 5:00 to 4:50. And also there is an option, but I couldn't burn energy for all things, would rather completing today's small dutie diligently, no adventure. As warm up, started very easy at 6:00 pace from my place, and got pace up by bits. I felt like I was running at under 4:40, because my heart beated hardly like couldn't take a breath lightly. After 3k warm up, arrived on the track and started pace run at 4:50 pace for 7km. I took an easy way to save my energy for tomorrow's training. It was hard one, tonight.

today's efforts:
time: 1h06m21s
mil: 12.65km
lap1: time: 4:46 avg HR:158-81% avg pace: 4:57/km mil: 0.96km
lap2: time: 4:54 avg HR:158-81% avg pace: 4:54/km mil: 1km
lap3: time: 4:46 avg HR:162-83% avg pace: 4:51/km mil: 0.98km
lap4: time: 4:52 avg HR:164-84% avg pace: 4:52/km mil: 1km
lap5: time: 4:45 avg HR:166-85% avg pace: 4:45/km mil: 1km
lap6: time: 4:51 avg HR:166-85% avg pace: 4:51/km mil: 1km
lap7: time: 4:25 avg HR:174-89% avg pace: 4:22/km mil: 1.01km
avg HR: 152-78%
avg Pace: 5:14/km
cal: 544kcal
beginning time: 8:05pm
location: Inokashira Park in the track
weekly mil: 20k