>A new metric
>Am I training on hillier terrain? It feels like it, but the Chilterns were pretty hilly as well. There’s something going on. Check out a graph derived from my training log:
|Miles per week (LH axis, blue bars) and TRIMP (RH axis, red line)|
This shows how few miles I’ve been doing, especially in the last month or so. The TRIMP figure is derived from analysis of time spent in different heart rate zones. In a normal week the line coincides with the top of the miles bar. If the line is above the bar, I’m working harder per mile. This happens in the first few weeks of training (2010, 46-48) and then settles down.
The figures from the last three weeks, though, show and even higher TRIMP/mile. I’m not working really hard yet, so this is surprising. What’s pushing my heart rate up? I’m fresher, I suppose, and heart rate is depressed when recovery is impaired. The time off for the move, fewer miles per week and the decision to train (for the time being) on alternate days means that my heart can get nearer to the maximum more easily and more often. The warmer weather is also a factor – heart rate tends to drop in cold temperatures1. But are the hills really hillier?
I’ve gone back through my training files (stored in a database) and created a calculated field of feet of ascent divided by miles travelled. Both figures are taken off my Garmin Edge 305 which I’ve been using since late in 2007. The ascent figure can be a bit flaky (it’s based, I believe, on atmospheric pressure) but over time I hope it gives a fair reading.
This week’s training gives me 60’/mile of climbing – the highest on record. Only six times have I exceeded 40’/mile since the end of 2008. Three of these are in the last three weeks (of the others, one included a long, hilly ride in Herefordshire and Worcestershire in 2010, another was a week in Brittany in 2008). Yesterday’s 32 mile ride (Bexhill, Catsfield, Netherfield, Dallington, Rushlake Green, Hailsham, Windmill Hill, Ninfield, Bexhill) gave me a return of 74’/mile, the second best on record behind a 10 mile ride in Herefordshire last April. How I must have avoided those Chiltern climbs!
I love numbers me.
A friend of mine once asked the great Paul Carbutt how to get fit. Carbutt just said “head for the hills.” I hope he was right.
1 This variability is one of the reasons why some sports scientists despair of working with heart rate. Those with big budgets prefer working with power meters.