Saturday, December 29, 2007

the race data, of course

A win is nothing without data, eh?

OK, D-grade crits at the CCCC are short - 30mins plus a lap (another 2km, so about 16-17km). We start with the "D1" kids and drop 'em off after 2 or 3 laps, so we start slow, slow but then speed up. It was 32 degrees Celsius off the tar at 6pm - hot. And the wind was 30kmh from the NE. I was on the Felt F-50.

I dump my ibike data into a spreadsheet, so it comes out like this:
MAX power
AV (all)
Max power is peak power. With the ibike it's susceptible to lifting wheels, and the combination of pulling up on the bars on an 8% hill during a max effort bridge to the attacker probably distorted the real power... so let's say it was 1,000W anyway, if not 1,400.

The all-up average treats coasting as part of the race, hence Av (all) is just 104W but (Average (>0W) removes all zeroes... which is more 'real'. 151W still sounds low - but we did start slow!!

That's my own normalisation formula, by the way, and definitely a WIP. As a relative measure it gives me a way to judge between efforts. It emphasises the middle over the high-end of the power output range and tries to indicate real effort - all soft-pedalling or coasting is removed and we are looking at just the real "training" load, but I haven't yet perfected a way to recognise effort over time... so short rides are favoured over long ones. I'm working on it.
600-700W 0.15%
500-600W 0.46%
400-500W 2.49%
300-400W 7.02%
200-300W 12.57%
100-200W 32.88%
0-100W 43.51%
This breaks-down the power into steps. I can see that 43% of my race was coasting or drafting (0-100W). When training I seek to minimise this figure, to actively eliminate those slack periods, In a race I take full advantage of these "rests".

You can also see that there were only a few 600W+ efforts, and the 300 and 400W steps represent the once-per-lap climbs. Knowing all of this allows me to finetune my training to meet my race needs, although C-grade may well be more "attacking" and both the averages and the peaks will be higher (and more frequent in terms of peaks).
695 VAM (max)/hr
10.5 Slope % (max)
-0.44 Slope % (average)
32 ALTITUDE (max)

50.53 VELOCITY (max)

25.0 VELOCITY (average)

The VAM is useless - not enough hills! But the 50.53kmh peak velocity in the sprint in useful. The 25kmh average is misleading as it covers 20km - warm-up, race and cool-down. The race itself averaged 32kmh (slow, I know, don't rub it in).