My last 70.3 run was a lot slower than my low-end expectation, so I am curious about outside input…
My recent open half marathon pace was 7:42/mile. The conditions were ideal at 42° with low humidity. Based on that, I had hoped to run around an 8:00 pace and no slower than an 8:30 pace in the Gulf Coast HIM.
I averaged 9:00 at Gulf Coast and faded in some of the later miles to the 9:20s. I felt great when I got off the bike and started at a sub-8 pace. I had to consciously dial back to 8, and I held that for the first four miles. But then I faded very fast. I never walked (except pauses at most aid stops for water & calories), but I could not muster a fast pace.
I don’t think I over-cooked on the bike. I rode at 75% FTP and easy RPE expressly to conserve for the run. My average HR in the run was a few BPM lower than my much faster HR in the open half marathon I referenced.
Gulf Coast was very hot, so maybe it was just that. But, heat alone doesn’t seem like it would slow me down that much. And, many others ran fast.
I don’t think it was hydration, because I drank four or five bottles on the bike and I did pee during the run.
I thought I had decent nutrition, but maybe not. I took in around 700 liquid calories on the bike and a few small cups of Gatorade on the run.
Is it run volume? Not enough bricks? What else causes a big disparity between HIM run and open HM run paces?
Without knowing what your training is like (swim, bike, and run), it’s tough to diagnose based on what you provided.
However, you ran a stand alone half at 7:42 pace in completely opposite conditions compared to Gulf Coast. I wouldn’t expect anywhere close to that in a hot/humid 70.3. Heat affects you more than a think. Especially since you are comparing a 1:45 race to 5+ hour race.
This year training has been a little lighter than past years in volume, but stronger in intensity. I probably averaged around 10 hours/week in 2019, with 2 hours week swimming, 5 hours/week biking, and 3 hours/week running. My swimming is 2x 3,000 sessions/week with a mix of short to longer intervals. Bike is fully TrainerRoad led (so hard). And run is a mix of intervals and long runs. I only run 25-30 MPW and try to conserve due to a janky knee that would get injured if I loaded up too much volume.
My overall time in GC was 17 in AG (top 10%), and if I can figure out how to sort out the run, I should be able to nail top 3-5 finishers in AG. My bike was almost recovery RPE, with avg. HR 15 BPM below my run HR. I was seriously holding back to try to have max gas for the run.
I know an HIM run will be slower than an open HM run and that heat will be another slowdown factor. But, 75 seconds/mile seems slower than it should have been. Especially given that only 1 of the finishers ahead of me in my AG ran slower than me. And everyone else (the other 15 faster finishers) beat me beat me by a lot, like by an average of 10 minutes faster than me.
So, I have concluded that compared to other top AG competitors, I am doing something big-time wrong on the run that everyone else (and by everyone else, I literally mean everyone else but one person) is doing right.