Jan, thanks for your detailed reply with hr data.
focus mostly on keeping things controlled and on recovery between the quality sessions from Day 3 to Day 8
that is the most important
once you adapt to the program, you will note things change on its own, your slow pace speeds up while the pace stays the same.
do hydrate well, especially when it is hot
the heat, certainly makes the pulse rate rise .. cooler conditions are always better
you coming along nicely