My theory: What I can do, you can do better.
My weakest area as an athlete (in my opinion) is in my head. It's always been a crap shoot whether I'll show up at a race prepared to suffer and put in the effort. Sometimes I've had it, often I don't. I've done a few things to address this including reading several sports psychology books which helped with technique. The takeaway from my research is the importance of race day routine, from breakfast to lining up at the start line. A routine helped me get in the mood to race, to focus and prepare for the work ahead.
I also adopted a new attitude of a "lunchbox runner." This isn't my big idea, but I can't give credit because I don't recall where I learned it from. The mindset is one of showing up to work carrying your lunchbox like a labourer might at a job site. If you're there to race, you're there to work. You have a job to do no different than shovelling a pile of rocks. Reframing racing to working has helped me immensely as it has shifted my attitude toward one of doing a good job and working hard rather than running for fun (which is still valid of course on races you aren't targeting for a PB).
There were a few techniques I learned from the sports psychologists that try and keep your mind off of what is ahead and onto what you are doing (being in the now). Common advice was to do simple math (maybe calculating your splits) or run to visual landmarks during your race. This should help divert your mind from the suffering of racing. However before this race I simply told myself I wouldn't worry about the kilometre I just ran or the mileage ahead but rather I'd stay focused on the one I was in. Each and every kilometre I paid attention to hitting my pace, my form and what was happening that exact moment. This sounds simple writing it out, but I can tell you not thinking about how I was going to do kilometres 17-21 during kilometre 10 was a game changer. If my mind did start to think ahead I told myself to stop it and focus on what I was doing. This helped erase any suffering or worry. All I ever had to do was run 1km at a time and that was always manageable. Try it, I think it'll help.
Moving off of psychology (where I needed the most work) I did a few things during training that were new to me. The first was track work at speeds that were more in line with a 5K or 10K race. I used my Garmin to prompt me during the workout (you can setup workouts ahead of time) and ran at paces up to 45 seconds per km faster than I planned to in the half marathon. I'll admit I'm unsure if this is good advice but my thought process was that running that speed would make the half marathon speed feel easy and I believe it worked.
I also did some interval runs at race pace with 5 minutes on and 90 second recovery. I did one at a set of 5 and one at a set of 6 at planned race pace. To do it again I'd add one with 7 intervals. These runs were big confidence builders as I felt the race pace to be rather easy.
Lastly I made sure that I did a few of my long runs in excess of the half marathon distance so that the 21.1km race would feel short or well below my endurance ability. I'm loathe to suggest this for a marathon, but the half is a manageable distance to do some extra distance without needing extra recovery time during training.
So how did this all go? Well I had planned on a 1:24 race as my A goal and a 1:26 as my B goal which would have still been a PB. I was very confident I could do a 1:26 but unsure of the 1:24. To get my A goal I needed to go out at a 3:58/km pace and hold on for the whole race. Given that this was a very flat course I decided that an even pace was the best strategy. I did go out too fast in my first km (3:43/km) but was mindful that that may happen and did slow down within the km forcing myself to relax. After that I settled in nicely with even splits up to 17km. At around 9km I passed a couple of runners I'd been shadowing and had some momentary doubt about whether my pace was too quick. I had been averaging a couple of seconds per kilometre faster than my plan but I felt good and I shook the others out of my head focusing on what I was doing.
The first 16km felt very relaxed. I was working hard but not suffering or in any trouble at all. In this race they let the marathoners go out first and I started catching them at 15km which created some road blocks I had to dodge around. There was also some bad course marshalling that gave me momentary bouts of panic that I was turning the wrong way. At 17km I started to drift a bit and slow down. I suspect it was a combination of fatigue and running through thick crowds of the slower marathoners. I simply focused on what I was doing and despite the harder effort still wasn't suffering. My pace dropped at times about 4 seconds per km but I had time in the bank and I never worried about it. I felt like I could have pushed harder but at this time I knew I had my 1:24. At kilometre 20 I felt a slight stitch in my side but was able to ignore it as I had just 4 minutes to the finish line.
Turning the corner for the last 100m I heard my wife almost right away yelling. She was surprised as I told her if everything went well I'd cross at 1:24. The clock read 1:22:something. I pressed on the gas to trying to nab a 1:22 and crossed just before the clock turned over. My gun time (that's the time from the starting gun not when you cross the start mat) ended up being 1:23:01 which was a bit sad but my official chip time was 1:22:57 a full 1:03 faster than my A goal.
My next goal races are a couple of 10K and one 5K in late winter/early spring. I feel that my window of getting a PB at those distances is closing as I age. I'll be using some of the above principles to help myself train for those events next year. In the meantime I've also qualified for the New York Marathon and I'm trying to decide if I should register for the 2019 race or if I'm done with the marathon distance (for now).
I hope you find some of the above tips useful. I wish I'd employed them years ago, but I'm always learning. I hope you are too.