There is always talk on the forum of overbiking – and the prevailing wisdom that if you have a good bike leg but a bad run leg you must have over biked
I think this is too simplistic, and there may be other factors involved

I did an IM at the weekend and was speaking to a guy in the tent after and he said he finds the IM leg so frustrating. Nothing can prepare you for it
You can do multiple 30 km runs in training – they are nothing like the IM leg
And if you really prepare for it – say do a 4.5 hr bike ride hard, and then run for 2.30 after you will be so fried after you will miss 7-10 days quality training. And the reality is its the last hour on the run that does the damage - the DOMS of a 2.30 run are half that of a 3.30 run in training
And we are constantly told an IM build is consistent day to day work

There is also the variable of the weather
In mainland Europe it can be cool on te bike and then 90F by the time you are running
So in a way you want to push the bike to try and start the run before it gets very hot
The cruel irony is Pros get the early stats and are finished first
AG’ers wait 30 mins to start, bike 6 hs and then face searing run heat
That’s hard to train for – especially if you come from cooler climate

I have done 5 IMs before- my run leg has been anyway between 3.17 and 3.35
On Sunday it was 3.49 and I had the worst cramps I ever had; seriously thought I would DNF

This has led to a lot of doubts; I am now wondering did I not take enough salt, or did I take too much water?
Or did I overbike, or was my run training simply not enough?
Or was it simply a crazy hot day (95F) and you just need to accept that it will get messy?

But my running has been really solid; averaging 45-50 miles a week for last 12 weeks
I did a 4.48 bike leg; but on a TSS of 235
So I don’t think I went too hard on the bike; and saying go slower on the bike may have done nothing for my run time – just delayed my start of the run by 10-15 mins and extended the time in the heat

Its such a puzzle to solve; maybe that’s why it has a hold on us all