Originally Posted by
burnthesheep
Distance.
Issue is that 25w faster over two 5k runs per the runner power pace calculator is more time saved than 25w more over the 30k bike leg in a duathlon.
That's why in that link I said the faster the runner, the lower the equivalent distance; the slower the runner the longer the equivalent distance. Just saying "3x distance" is a ballpark. I showed a range and how to refine the ballpark.
[Edited to add:] Just to clarify, you're right that equal increases in power don't produce equal gains, but you can see that's because the actual relationship is nonlinear.