When I was 26, I would jokingly refer to my bike as the CWM (Cross Wind Missile). I'm not 26 anymore...

About Me

My name is Dean Russell and I raced road bikes and some track endurance in the 1990s. I stopped racing in 1999 when I was 26. After almost thirteen years of being a lazy slug I decided to put my sorry backside onto a bike seat and have another crack at racing. This blog chronicles my journey from being completely unfit and overweight to becoming one of the oldest Elite A grade riders in Queensland...and then slipping nicely back into Masters racing.

Saturday 7 September 2013

An Analysis of a Power File

I thought this might be an interesting exercise. If you look around the web you will see quite a few people who have analysed a power file after a race. Normally though, they are crunching the numbers after they have had a win (or gone very well at least). I thought it might be insightful to do it after a race has gone spectacularly wrong.

This file is from the recent Masters 3 (40 - 44 years) Queensland Championships Individual Time Trial, in which I finished 5th. I should probably say that I have appreciated people's kind words and congratulations for this result. I should also keep things in perspective; 5th in the state (in my age group) less than two years after getting back on my bike is not bad. If you know me well though, you know that I was keen for a better result here and when you analyse the power file (as we are going to), you will see that 5th is a bloody miracle!

I should also add that I apologize if my analysis is a bit on on the amateurish side. I have only been training with power since April of this year. I have read just about everything out there on training with power and have had a lot of help with my program from Mark Brady who is a great mate and an excellent coach (based on the Gold Coast). 

The course was 20 km out and back at Purga (near Ipswich). A hard up and down profile that would require a balanced effort to be successful. As a 27 - 28 minute effort, I had decided that a target of 380w average would be about right. I based that on the following previous efforts:
  • 32 minute criterium (I was away solo for 30 minutes of it) - 369w (average) / 397w (normalised)
  • 28 min time trial - 365w (average) / 368w (normalised)
  • 27 min time trial - 370w (average) / 376w (normalised)
  • 27 min time trial 383w (average) / 388w (normalised)
  • Consistently doing 2 x 20 min efforts at 370w - 380w in training
My power from this particular race was 338w (average) / 340w (normalised). I barely managed to keep my average power in the threshold range. If you have been following my blog you will know that I have been struggling badly with colds and bugs for over a month. That has definitely impacted here. I must say though, that I actually thought I had come good for this race. Despite the impact of the sickness, there are still some other interesting points in the data. So let's have a look at it:

















Okay let's explain some of these lines. Power first. The grey line is my target average power (380w). The green line is as high as I wanted to go on the hills (no more than 410w). The pink line is as low as I wanted to go on the downhills (no less than 350w). It should be fairly obvious how this panned out for me. Not bad at the start, but then it all fell apart. I should also add that we are looking at a 10 second smoothing of the watts here, which is what I actually use when I race.

The first 12 minutes or so, I actually felt like I was on target for a really good ride. I was chasing (at 1 minute) a rider who had produced some very good time trial results at masters level (Chris Millen) and I was catching him pretty well. I had gone a little above and below my target power but was feeling quite good. I went maybe a touch too hard up the first hill, but at the time I didn't think it was anything too drastic. You can see (even when I felt good) that I was having some trouble keeping the watts up on the downhills. Was that start too hard? Maybe...

After 12 minutes (the black circle) it all comes crashing down. I definitely hadn't overcooked it on that hill (in fact the section before it fell apart was the most balanced of the entire race), but you can see the power go down, down, down.

After the turn (at the turn I estimate I had only lost 10 seconds or so to the eventual winner John Murazak, who would go on to beat me by over a minute) things go from bad to worse (the brown circle). I am having extreme difficulty getting anywhere near my target power. It looks like I am fatigued and ready to stop and that is probably about how I felt.

As we get nearer to the finish (the pink circle) you can see me starting to panic. I know these last few hills are hard and I try my best to drive up them, but you can see the impact that has overall as I can barely produce any power going over the other side. It almost looks like I am doing intervals! You can also see that I try to 'bring it home' but can't even sustain that acceleration and increased power for very long (I actually blow up completely).



So what can I take out of all this information?

It's been said a thousand times before and I'll say it again. Don't start your time trials too hard. On the road this start felt good, but it was obviously just too quick, which impacted on me later.

When riding time trials with hills, we all know that we need to 'feather' our power up and down. The surging  approach that I used in panic mode late in the race is not effective at all.

It is also obvious to me that I am still not 100% recovered from my colds and bugs. The really telling thing for me is my heart rate data. I know a lot of power users ignore their heart rate all together but I still find it very useful. In time trials, I will generally start at about 165bpm, quickly build to about 170bpm - 175bpm and then in the last few minutes can really bring it home up to 185bpm - 190bpm. The yellow line on the chart is 170bpm. That is actually quite scary. I was cooked (in terms of heart rate) pretty much the whole race. I hit 190bpm (which I consider my maximum) several times throughout the race. A big sign for me that 'all is not well').

So in summary, if you want to learn something from this analysis:
  • Don't start too hard.
  • Take a balanced approach to time trialing on hilly courses.
  • Don't race unless you are 100% well.
Very happy for people to provide a comment if they have further analysis.

Histogram as requested for extra analysis:


7 comments:

  1. You also get what you train for, if the training is done patiently, over a period of time and with adequate recovery. Staying healthy helps too clearly. Train for the hard start. Use your power meter to hold yourself back within the range you know you can recover from initially. It's still important to listen to the body too, which takes a lot of time snd intuition. Sometimes a bad day just happens too! Then you have to trust your program and coach! Draw a line and don't dwell on the result. Move forward positively. Also consider whether it was too much self expectation or pressure which can stimulate the central nervous system and raise the core temp to negatively affect the performance. Scientifically this is linked to 'choking' and inexplicable cramping episodes. Whatever though, there is always the next race :-)

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  2. Nice analysis for this race -- but as you have already realized, the context was that you were suffering from a cold before the race, so a proper analysis will include the bigger picture of what was happening to your power and RPE prior to this race. Did you do an "opener" the day before the race? What did your RPE or HR look like then? How much training "load" did you accumulate prior to race day, over what period of time, and was that ramping up, steady, or ramping down? Novices at power analysis look at the race file. As you get more experience, you'll evaluate the race file in a broader context of the files immediately prior to the race.

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  3. I had almost a week off two weeks before the race. I tried to treat that as a 'freshening up period' and then the week before I did what I would normally do before a time trial - some shorter higher RPM stuff and a few 8 and 10 minute efforts at TH (I had trouble with the duration of the efforts). My form in that last week was extremely patchy with wild swings of feeling great and feeling bad. I did my standard openers the day before and didn't feel too bad.

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  4. Gary K thanks for the input as well. Food for thought. I don't think I got caught up with the expectation of the event. I've always managed to keep that kind of thing 'in check'.

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  5. I think your illness is a major factor. I see it all too often. You raced well on the Glencoe circuit, but maybe that kind of effort so close to the event took too much out of you and you weren't able to recover properly? A shafted immune system takes much longer to recover from a standard session, never mind a hard and hot circuit race mid arvo after a lot of waiting around! Like I said on FB, I'd have to see the 3-4 months worth of data leading up to this to make a reasoned and contextualised analysis.

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  6. Yeah, the wild swings in feeling great and bad for "normal" amounts of training are a big clue. I used to think that if I had wild swings leading up to a race maybe I'd luck out and race day would be one of the great days -- nope.

    That's a "bumpy" but not "hilly" elevation profile. Power seems high for that speed. Was this a Merckx-style TT event? Possible slight headwind outbound and slight tailwind inbound?

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  7. If anything the wind was the other way - slight tailwind out and slight headwind back.

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