HR Swim (and pace) training

The other day there was a thread about HR vs. Pace training. I kept track of my times every 250y for a 1900y swim (ran out of time or I woulda went 2000y). The HR was held as close to 150 (determined by PC Coach) as possible. The results show …

250y = 6:37.54
500y = 13:12.7 (6:35)
750y = 19:57.12 (6:45)
1000y= 26:37.92 (6:40)
1250y= 33:23 (6:46)
1500y= 40:26 (6:49)
1750y= 47:02 (6:36)
1900y = 51:11 (4:09)

In the other thread I mentioned that often times HR and pace will be very close, and that it might not be necessary to “pick one or the other”. For this situation, it seems that pace and HR are congruent with each other.

The idea of HR training (from what I gather) is to increase the pace at the same HR as an indicator of increased fitness. So, in another month I should see the same distance at the same HR with a lower time for each 250y interval … otherwise HR training is not working as I want it to.

Wondering if anyone else has experienced HR and Pace being consistent with each other?