Eight Minutes Faster: A New Half Marathon PB

North Downs Ridge 50k Training Block - Week 2/17

There are long runs, and then there are long runs with a personal best attempt hanging over them. Yesterday's half marathon definitely fell into the latter category. I'm not sure whether it was the anticipation of the distance, a bit of pre-run anxiety or simply the knowledge that I was going for a PB - something I don't normally set out to do - but things didn't get off to the best start.

Almost as soon as I started running, my heart rate shot straight through Zone 2 and settled firmly into Zone 3. Normally, I can comfortably hold my planned pace in Zone 2 for at least the first 10km, but that clearly wasn't going to happen today. It's amazing how quickly those little seeds of doubt can take hold. Before I'd really got going, I was already questioning whether the attempt was going to work out.

The weather, at least, was absolutely perfect. Clear blue skies, around 10°C and very little wind. Pretty much ideal running conditions. I had two gels with me and a 500ml flask of water, so in terms of preparation, everything was in place.

Once I'd managed to put the elevated heart rate out of my mind and convinced myself that it had stabilised, I settled into a comfortable rhythm. The route was planned around three loops: an opening 8km, a shorter 5km loop and a final 8km to bring me home.

The first loop passed without any real issues. I was feeling comfortable and making good progress, which was exactly what I'd expect at that stage of a half marathon. The shorter second loop was much the same. I was still feeling good, and reaching the 13km mark at the pace I was running was never really in doubt.

By the time I started the final 8km, I'd taken both gels and kept on top of my hydration. I still felt as though I had plenty left in the tank, but I wasn't going to take anything for granted. I was already several minutes ahead of the time I needed for a PB, which gave me a little breathing room should things get difficult later on. And, as it turned out, they did.

I can't remember exactly when fatigue started to become a real factor, but somewhere around 15km I began to feel the effort catching up with me. It was manageable at first, but by 18km it was becoming considerably harder. I was trying to maintain a pace around 5:50/km, but my Garmin was occasionally telling me I was dropping back towards 6:10/km. I knew I had the PB comfortably within reach, but there was another target beginning to emerge: could I get as close as possible to the two-hour mark?

So I pushed on, settling into something closer to 5:45/km, even though the effort was becoming increasingly uncomfortable. The final 2km were brutal. Every instinct was telling me to slow down. My heart rate was getting close to maximum, my legs were tiring and it took a considerable amount of concentration just to keep the pace going. I somehow managed to keep pushing, finishing the final kilometre at 5:35/km. By that point, I was completely exhausted, and those familiar Garmin finish beeps were very welcome indeed.

21.1km complete. Job done. Final half marathon time: 2:03:33

That's an improvement of 8 minutes and 27 seconds over my previous PB of 2:12:00, set in Portugal in 2025.

And there was more to celebrate than just the half marathon. Along the way, I also picked up personal bests for:

• 15km
• 10 miles
• 20km

I also recorded my second-fastest ever 10km. I'm absolutely delighted with that result. Getting so close to the two-hour mark was a real bonus, particularly given how difficult those final kilometres became.

Now that I've got this PB attempt out of the way, I'm looking forward to approaching my forthcoming long runs a little differently. The focus can go back to what it should be: time on task, building endurance and getting the miles done without worrying about chasing times or trying to beat previous performances.

First up, though, is a deload week and a couple of days of much-needed recovery. I think the legs have earned that!

One final note: I didn't actually take any pictures during the run, so the photos accompanying this entry are from a walk I took later that afternoon at Wakehurst Place. A rather more leisurely way to spend the afternoon after that morning's exertions.