Hill VO2 50:00 [4] 9.26 km (5:24 / km)
ahr:150 max:181
This one was tough!
Warmed up at 6:00 (on a TM that really feels faster than outside!).
On hill section I ran first 3 at 5:00 but that was way too hard to proceed so I lowered pace to 5:07 and ran all the rest.
Last 15 minutes were at 5:30.
Seems that my HR strap died, hope these are just batteries.