I am pleased to say I successfully completed the Luton Marathon last Sunday in 3.36, which is a new PB for me. After the half PB I picked up the last 6 weeks of the marathon training plan and all went perfectly.
Hi Cookie, if you're getting bored, I don't see any harm in mixing it up. Try being constant steady speed for the first half of your run then really pushing on for the second half. Or variations of that. I did my best half marathon and marathon time doing negative splits, and you get a boost when you're generally overtaking others at the back end of a race.