In my last blog post I offered the observation that all of the experienced triathletes I've coached over the years typically had lower cadences in Ironman-distance than in Olympic-distance triathlons. Several readers asked how that may have affected their run times. I really can't say because they seem to have always done that. So I have no data from triathletes who used a higher cadence, or even a similar cadence, in Ironman races as they used at the shorter distance. But it is a great question. So I took a look at the research to see what it says.
Unfortunately, there has been very little research on this topic. I found 5 such studies. None of them addressed the issue of the effect of cadence on the run at different distances. The longest ride in these studies was 30 minutes. Some were only 20 minutes. They found three results: 1) run times were faster with a slower cadence, 2) run times were slower with a slower cadence, and 3) there was no significant difference in run times regardless of cadence. So the matter remains to be resolved. You need to decide what works better for you - which is what it almost always comes down to anyway.
If you want to read the abstracts yourself go here.