That's like the lowest my heart rate goes on a run (and that's very easy runs) :p. Think I averaged like 180-185 on my 20k the other day with a max of 199. You're much kinder to your heart it seems ;)
And nice running! Sub 80 should fine if you get the pacing decent and have some legs for the last 8km or so.
That is the highest I've ever seen mine go! I think it's just a bit lazy ;)
Thank you! I really hope so...it's going to be quite close, but I'm really excited to give it a crack :)