Good afternoon.

What should my heart rate be if I'm 40 years old and my pace during long-running is about 4 min/km?

Good afternoon, 

I want to run my first ultra (70K race). What the longest distance should I run during training for it and what time before the race?

I think it can be 50 km distance a month before the race.

What is your opinion?

I like to run a lot but slowly (6:30 - 7:30). I don't want to run faster but I want to run farther. I've completed a marathon and I'm going to run an ultra-marathon.

Is it enough to do long runs and strength trainings or not?

Good day.

What's a good running pace for a half marathon 2 weeks before the marathon race: marathon pace or usual training one?

Good day.

Is it possible to reach a pace faster than 4:00 minutes per km in 1-2 years of training.