Lies, damned lies, and HR data: Stubbington 10k 2008

I usually do a race report then add the HR data at the end, but let's get straight in there with a HR analysis (that's Heart Rate, not Human Resources, in case I've just caused a flutter with any personnel department workers):
4:27 135bpm
4:32 146bpm
4:38 148bpm
4:18 147bpm
4:25 148bpm
4:21 148bpm
4:20 146bpm
4:29 148bpm
4:38 149bpm
4:28 147bpm
Overall: 44:41 146bpm
Ave pace 7:11/mile

So that's over 3 minutes down on my best - an indication of the loss of fitness I've suffered since injury.

Hang on a one second though: take a look at the overall heart rate figure. I've run a marathon at a heart rate higher than that. Look at the pace too. If I can manage that pace/HR for London I'm laughing: that's well inside the pace needed for a sub-3:15 marathon.

There are 2 effects in action here as far as I can tell. Firstly, and most importantly: fatigue. I've been training hard, within the limits of the 30-40 miles my body can stand in a week at the moment, and I didn't taper for the race, except for a day's rest on Saturday. As I've seen in the past, this doesn't generally affect my HR/pace relationship: for a given HR I can generally maintain the same speed regardless of how tired I am. The way fatigue affects me is my ability to maintain a particular effort level or HR. I have been able to maintain 155bpm for a 10k in the past, but when tired I just can't get my HR high enough.

Another effect is lactate threshold. The higher one's lactate threshold the higher a HR one can maintain. My LT may well be down at the moment, but surely not by 10bpm? Regardless of my LT level I would not have thought a suppressed LT would cause a drop in the pace/HR relationship though - HR is a fairly direct measure of oxygen consumption which in turn is a fairly direct measure of energy consumption (when operating aerobically), so my running economy, the energy per mile, seems as good as ever. The main effect of a suppressed LT would be my ability to sustain a particular HR for the entire marathon distance. Maybe what the data is telling me is that my endurance is down, but not necessarily my pace? I won't know the answer to that without blood lactate measurements.

So what I'm saying is despite being 3 minutes down, I can take a lot of encouragement from that result that I haven't lost the amount of fitness I feared.

I have many long runs to do between now and 13th April, but things are looking good!

As for actual reportage, the race was dry, temperatures very mild for January, but it was very windy. This was particularly a problem along Lee-On-Solent seafront but it didn't bother me too much, although it would certainly have added a chunk onto my time. The split start, now in its 2nd year, seemed to work quite well, with us sub-45 runners going one side of the roundabout and the slower runners going the other side of the roundabout. There didn't seem to be so much barging this year when the 2 sets of runners met up. As ever, the organisation seemed very good - a top 10k.

As for the team, despite what at first seemed a disappointing turnout from the girls, through injury and illness, and a small matter of a XC race the day before, thanks particularly to Miranda and Lucy we actually scored quite well to put us a solid mid-table in Div 1. Nice work girls!

The men too, although not of course showing the same quality as the girls, fared well to find themselves 7th in Div 1. Keep it going boys - don't let yourselves drift any lower though.

Next up, the Ryde 10 on 3rd Feb - see you there!