Our triathlon team, Endurance Nation, is known for the effectiveness of its racing execution, and an emphasis on continuous improvement. The coaches have been shifting from a pace-based strategy for the Ironman run to a heart rate based strategy. I joined the conversation with the following somewhat technical post:
I’ve reviewed the data I have for my IM runs since 9-05. There was a period when I stopped wearing my HR strap, so I don’t have complete data for all my races. But two years ago, @ IM AZ, I produced a marathon which I think can serve as an example of what we’re talking about here. I can’t use the tool Coach P made, as I don’t have access to any compatible spreadsheet programs, but here is pretty much the same thing in a WKO graph (from the NEW Mac version!)
The HR is continually rising throughout the run, along with the pace (getting faster) and cadence. Note a few points:
- In the first mile, my cadence was “low” (84/6), but my HR was “high” 120-30 as I adjusted my pace – see the little blip up[ in speed which I corrected.
- After that, the HR and speed slowly rise to about mile 18/19. Then, my cadence stabilizes @ 89/90, I start taking a little longer in those aid stations, which allows my HR to “recover” down to 100 for maybe 10 seconds.
- The drop to zero in cadence and pace at mile 21 is me stopping to throw up.
- In the last mile, my HR reaches its peak over 133.
- The first 13.1 was covered in 2:08; the second, 2:03. This was about the 6th or 7th time I even or negative split the marathon.
Apparently, I’m one of those bad examples who can even/neg split the run. Not saying that’s the right or wrong thing to do, it just happened from the way I approached the challenge. Here’s how it goes, in a nutshell: take the first mile to settle in to a pace which feels SLOWER than my weekly long run pace. If I hear myself breath, I’m going too fast. Then, simply “let” myself go a bit harder with every passing mile. I think I perfected that process in this IM AZ ’13 race, and discovered that my HR was doing just what Coach P said it should. I was surprised by how high my HR could get, and I could still maintain running form (cadence, posture).
Now, here’s a graph of me “blowing up” at the end of the run, just to show it’s a knife edge we’re running on. This is from last week’s IMLP. The grey area shows where the hills are
:
- Not how my HR goes “thru the roof” climbing the hills @ miles 11-12.
- My cadence never gets above 85 or so.
- My HR rises in the second half, but my pace doesn’t come along with it.
- Once again, I throw up @ mile 21.
- Then, the final hill @ mile 24 knocks me out, and the rest of the way of walk/run with my HR dropping as a result/
- The last five minutes are after the finish line as I was so out of it I forgot to turn off my watch.
The difference between these two runs, IMO? Poor attention to hydration during the bike, first off. Next, the temp was 10-15 degrees higher in LP, AND the temps were dropping in the second half of the AZ run, while they were RISING in LP. The HR can help with the latter (remind you slow down when its warmer), but not the former. You still have to execute the bike properly to set up a satisfactory run.