Anatomy of Personal Best

In April I set a new Personal Best in the half marathon distance.  Going into the race I felt like I had a good chance to set a new PB but as race day approached I did not think the weather would be conducive.  Typical of most runners I started looking at the weather forecast well in advance and it was not looking pretty.  I remained optimistic the forecast would change for the better but expected the worst. The night before the forecast had not changed and when I woke up the forecast had come to fruition.  

Windy and Wet

I resigned myself to just having a good race and pushing myself as hard as I could on race day. I was still going to try and get the PB but was aware that the conditions may not allow it. The course was an out and back with the wind at my back for the first half and into my face for the second half.  The plan was simple, take what the conditions give you.  In this case that meant going out fast since it was unlikely I would run negative splits into a 20 mph head wind. I wanted to run around 5:48-5:50 on the way out and whatever the wind would allow me coming home. Below is how it played out in the first half.

First Half Splits (4/25/21)

As you can see I was right where I hoped to be, but after 7 miles I was still behind my old PB split as you will see below.

Mile Splits From Old PB (10/20/19)

Looking back and comparing the splits I was surprised that after 7 miles I was 11 seconds behind where I was at that same mark from my previous PB. Even more so when I consider the advantageous conditions for the first half of my race. At the half way mark I was really just hoping I would break 1:19 given how much of a head wind I would have to deal with.

There was one variable which would play to my advantage. I had run with two other runners during the first 5 miles but they had pulled away. Not so much that I had slowed down but more so that they had picked it up. One of the two was very strong but the other seemed to be laboring and in the back of my mind I thought I would be able to beat him even as they pulled away. Having that carrot out in front of me was instrumental in helping me get the PB.

I am not sure by how much this other fellow separated from me, but it was pretty significant. At the 10k mark he had 7 seconds on me and that was extended to probably 20 seconds by mile 8. I slowly started creeping up on him and around mile ten I caught him and passed him. I did not pass him with a strong move as I was not quite ready to push the pace. About a half mile later he passed me back and extended his lead over me to probably around 10 yards. I let him maintain that lead for the next mile or so as I wanted to keep him in check but not get much closer until I was ready to make a definitive move.

At around eleven and a half miles I was ready to go. I knew at this point I had to make a definitive move and maintain that through the finish. I slowly started inching closer and as we approached the 12 mile mark I made my move and pushed past the other runner. He responded and stayed a few steps behind for the next quarter mile or so. This was bit discouraging as I was hoping this move would “break” him, but it appeared not be the case. I dug a little deeper and really put the pedal down over the next quarter mile and this appeared to finally “break” him. I was not going to get complacent and instead I continued to accelerate as best I could all the way through the finish, crossing the finish line in 1:17:42. I ended up beating the other runner by 36 seconds.

Below are my splits for the second half of the race.

Second Half Splits (4/25/21)

Compare these to the second half splits from my old PB.

Second Half Splits From Old PB (10/20/19)

A couple of things to note when comparing the two:

  • The wind definitely slowed me down in the second half of my most recent race
  • I crushed my last few miles. Comparing my recent PB with my old PB I was surprised to see at mile 11 I was 15 seconds slower, at mile 12 still 5 seconds behind pace, but ultimately beat my old PB by 27 seconds.
  • Having competition and someone to chase down helps immensely.
  • Not looking at your watch and racing can lead to good results
  • Sometimes having poor conditions can be a blessing as it takes some pressure off

Obviously, I am stoked to get a new PB and how I raced, but am a bit disappointed that I did not get conditions that would allow me to go after what I was hoping to achieve which was breaking 1:17:00.