One week to London Marathon . Getting nervous now. I know I can finish ( if nothing goes wrong) but I want t mo beat 4 hours which would be a huge achievement at my level.
I ran 3.57 and 4.03 22 and 23 years ago with a LOT more training and I’m now 56! Would love to run the same sort of time to prove I’m not getting old

to myself.
I always fade in the sec half. Have read conflicting advise on basically running 47/53, so 47% of time in first half, 53% second half (1.53/2.07) .this is how I would naturally run.
I know I need to focus on not going out to quick
Which is what I always do as 20 seconds a km faster at start= 40 seconds a km slower at end , or worse
Other articles say you should keep the same pace as more efficient. I know this makes sense and I could join a pacer but I just can’t see how I can maintain that pace on the last 6 miles. I need some buffer surely?
I am assuming the pacers so run at a constant pace?
Thoughts from any marathon runners?