Hey Marco, well since you fit in the group of big guys who struggle on the run.
It definetly limits how much *risks* you can take in run training/racing.
But with proper approach, im convinced you can get the best out of yourself.
Im gonna go a on a ramble here.
To keep the theme of this thread going

But will come back to you at the end.
Okay, before and after I went to Kenya.
I had heard many difference stories about the Kenyan run regime.
How they did very slow long runs and very fast long runs.
But once I got there.
It wasn't one or the other, well only occasionaly.
If I had only one word to describe their overall training.
Would be *PROGRESSIVE*
And it only makes sense when these guys are running 250+ km a week.
Starting slow would allow them to loosen up from previous heavy training sessions.
Also allow to slowly loosen any minor injuries that they might have.
And more importantly, training a greater range of running speed.
In mainstream running/triathlon now a days.
You hear all these expressions, like aerobic threshold, race pace, zone 1-2-3-4-5, ect.
Which helps to nail down what your working on that day.
But in revenge, it can cause athletes to over reach or simply overthink their session.
Especially armed with heart rate monitors and garmins and power meters.
It helps them to get into their *mode* much faster.
The Kenyans would instead *ease* into most of their sessions.
Track/hill reps/long runs/ect.
Because if they would have a go at it from the start.
Then they might not be able to get in as much volume.
Or simple feel off from the start due to accumulated fatigue.
Where that can play a nasty game with an athletes head.
So a typical 30km long run.
They would run the first bit in lets say 6 min km's.
Then at the bottom of a hill, then would kick it down to 5 min km's.
Until they get to a particular dirt road, where they kick it down to 4 min km's.
Now that their past half way, they pass a big tree thats there since Kip Keino's era.
They kick it down to 3min km's.
Until they pass that elementry school that many of them went to.
Where they kick it down to 2:45 km's and maintain that or speed up.
Until they reach that little eatery that serve great millet poridge with honey and lemond.
Done, regroup and enjoy the poridge!
Okay, so the numbers I used are well kinda of arbitrary.
But just to get the point accross that they will run bellow/at/above their race pace.
And they not bothered by exact distances, but by land marks.
Since very often, the particular circut they run, as been pounded for generations of runners.
Today, their goal is to run those loops faster and faster.
So Marco, if you slow down at the end of your long runs.
Chances are your starting to fast in the first half.
Once I was shouted at during a long progressive run by an unknown Kenyan as I was getting dropped.
"MIZUNGU, dont not teach the body to slow down, only to acclerate"
This progressive approach, historicaly doesn't suite a fast marathon off a 180k.
Because the top IM athletes seem to run better by starting fast.
To nail their rythym when they feeling good, well relatively...
But that doesn't mean that doing progressive training doesn't have its place in triathlon.
Because speeding up at the end of a run session will teach your body to run through pain and strain.
Which is a crutial part of good finish on the run.
So try it out on your next long run, and let us all know.
Start out slower than normal, build into your race pace.
And then kick it above at the end.
Im convinced, you will walk away from that run, a bit stronger.
Than a blow up run.
More importantly, your brain will have had a solid effort as well.
Especially in the departement of patience and content of a good long run.
Because at the end of the day.
Weather your tired from 250+ km week of running.
Or a heavy block or swim/bike/run.
Or a long day at the office.
Starting your run session a bit slower, or even a swim/bike/run that is.
And then building into it, and then going above at the end.
Will be more beneficial than blowing up or cutting your session short.
Because your could not it the numbers.......................................