When I set out a few goals at the start of the year, one of the main priorities was to get my half marathon personal best down.

Before Sunday my Royal Parks time of 1-48:40 was the pinnacle of my half marathon career so far.

I hadn't trained for that event – last year I had prioritised the Robin Hood Marathon and after that was completed the residual fitness attained during that training block netted a bonus PB.

I knew I was capable of better and when it became clear that I wouldn't be able to commit to training for another marathon this year due to my second child being on its merry way, I decided to put all my efforts into running 13.1 miles as quickly as possible.

The Cambridge Half Marathon had been the initial targeted event but when a virus put paid to that, all my efforts went into Colchester.

I'd heard what a superbly organised event it had become and with it just being an hour away from a 38-weeks pregnant wife I could just about justify going.

What I hadn't checked was the elevation involved… ie how many hills there are.

Well a couple of miles in and I knew that I hadn't picked an easy one…

But I've changed how I run big inclines during races now. When I started running I used to treat them as my mortal enemy and blast my way up them as quickly as I could to get them done.

MORE: Which voice do you listen to when you're running?I would then often spend the next mile trying to recover from the extra effort expended. I really wasn't doing myself any favours.

So in my last few races I've decided to just run them on effort. Yes, I'll slow down on them but I'm now confident enough in my own ability to make it up on a flatter part of the course.

It still takes a bit of nerve. I wanted to run at 7:30-minute mile pace and when my Garmin buzzed with 7:53 for mile three, that doubting voice in my head piped up… 'you're falling off the pace already and you've still got 10 miles to go!'

But I told him to be quiet and sure enough I picked up the lost time gradually through the race.

I hit a bit of a sweet spot from mile 5 to mile 10 when hitting the targeted 7:30 felt relatively comfortable (thank you to the ladies handing out jelly babies around mile seven!).

But I knew the tough part of the race was to come. They say in a marathon that the race really begins at mile 20. I would say that a half properly gets started during the 10th mile.

My legs were starting to feel heavy and gradually I started losing time. I was checking my watch far more than I should and my average pace was gradually creeping up second my second.

By the last mile my average pace was at 7:34 and I really had to dig in when another hill, which felt like Mount Everest, hit me with half a mile to go.

But these moments are why I run, I like it when it gets really hard – you learn to embrace that discomfort you feel in your legs and your lungs and know that if it's hurting a little bit then it's only because you're doing it properly.

The training program Neil set in the run-up to Cambridge/Colchester meant I've got used to pushing myself when it gets tough and it certainly stood my in good stead in the latter stages of Sunday.

MORE: What are the five qualities you need to be a marathoner?I knew if I could keep my pace under 7:37 then I would go under one hour 40 minutes and that became my pure focus.

When I came into the home straight I knew I had enough time to appreciate that I was going to achieve this and nothing beats that surge of adrenaline you get from a crowd at the end of a race.

The pain that was etched across my face gradually transformed into a smile and I crossed the line in 1-39-20.

That's over nine minutes off my time at Royal Parks – a huge improvement over six months and one that even I'm pleased with despite being notoriously hard on myself.

So that's spring done for now…it's time to have another baby.

I know there are improvements I can make to bring that time down even further this year.

But that can wait for a few weeks as I try to let my body recover during a sleep deprived haze.

I genuinely can't wait.