Notes
Constant 8:00 pace. 800m reps @ 8%, 400m rec @ 0%. 1m w/u, 2.5m c/d.
HR v low for warm up mile (124 ave). Ave for reps was: 155, 163, 166, 168, 172 - so a fairly steady increase, to be expected. However HR wasn't dropping sufficiently during the 400m rec jog, so consider decreasing speed of rec jog - this was more like fartlek than an interval session.
Observation: Although HR was 124 @ 8:00 for warm up mile, it wouldn't drop below about 158-160 during warm down at same speed. Aerobic conditioning needs improving?
Deduction? Mid race/run surges are not conducive to achieving a good time as once you have raised your HR over a certain point it is difficult to get it back down again - so only consider mid race surge if it is going to win you the race, if you are after a decent time... save the surge for the end.