Weather: darn near perfect: cool, calm, cloudy.

Preparation: pretty good: possibly a slight virus in the week or so beforehand but did most of the training. 5 days of solid rest in the leadup.

Plan: easy first 500m or so to warm up, 3:50/km pace, still fresh after 3-4km then try to hold on.

Target: 3:53/km == 46:36

Execution: First 4 or so km were a glorious run. I was feeling really fast and fresh and really enjoying the whole experience. My heart rate (HR) was getting up in the high 170’s but I was kinda pleased since that was exactly what happened last year.

Unfortunately I really started to tire out around half way. I wanted to stop at the 6km mark, and was really feeling it by 7km. I felt just about dead by 9 to 10km. Thinking about the people supporting me really helped keep me going. My pace was right on target at the 6km mark (23:15) but was steadily dropping off after that.

I ran through a cooling sprinkler at 10km. This turned out to be a bad idea because it didn’t help at all and made my watch go silly. The touch bezel thought it was being continually pressed and started beeping a lot.

About 700m out realised if I put a kick in I could finish in under 48:00. Got up to 3:45/km pace or similar. Yay for the training. My HR was soaring by then, I was wanting to puke by the time I crossed the line, and a bit vague about what was going on around me. Sadly I failed to press the stop button properly on my watch when I crossed the line so not sure about the actual time. Normally I have my watch showing average pace and use the touch bezel to check time but that wasn’t working either. I think my watch measured the distance at just over 12km again, as my official time came in at 48:12.

In a comedy of errors, the timing chip in my number bib also failed. Fortunately, after some emails to the helpful City-Bay staff they worked out my time based on the shared start time with my running buddy and the finish line footage.

Analysis: with the benefit of hindsight, I probably ran my intervals too fast. My calves in particular were smashed, probably from the fast running early and the total distance. The final set of 2km intervals I ran the prior week was 4x at 3:51/km. I probably needed 6x or 7x at 4:00/km.

I’ve recently discovered race distance converters, such as the one at Craig’s running site. Based on my past two runs, I reckon I can estimate my City-Bay time based on a run of 11.65km. Two data points is all I need to extrapolate right? The shorter distance is to allow for me being completely fresh, and the run being downhill. The calculator shows very good agreement with my most recent 6km time: 23:55, 2nd fastest mile time 5:40, most recent 10km time: 41:00 and 11.65km time: 48:12.

The really interesting bit for me (besides the excellent fit of the model to my data) is that the recent 10km run was a lot more fun than the City-Bay. I think this is largely because the attempted pace was more realistic. I spent half the City-Bay just struggling to keep going, whereas with the 10km, I started nice and slow and really only went hard in the last couple of kms. Check out the charts below for the different effects. My plan for next year is to pick a sensible target pace a few weeks before the race and then train to that. The race converter will also help with pace setting on all my other runs, eg one mile, 3km, 4.5km, 6km. I can pick a distance, work out what pace I should be running, then work on keeping constant pace.

City-Bay 2012 and Recent 10k Run
City-Bay 2012 and Recent 10k Run

Again during the City-Bay, my heart rate was quite elevated, probably 15 BPM above where I would expect it to be at both rest and working hard. This may be due to excitement, adrenaline, a week of rest, and/or shivering in the early morning cold. I am planning to do a 6km with full race prep in April next year to do some more testing.

I’m also planning on doing some longer runs at very slow speeds. This will help build strength and allow me to work on technique. As previously mentioned, my calves were quite hammered by the end of this year’s City-Bay and I suspect that was a part of the cause of me slowing down.