Thursday, 15 March 2012

squeezing TSS and IF metrics from the Garmin

TSS and IF Reference Charts
Thursday evening I was out for an agreeable supper in a fancy restaurant. It's another one of the times when I've not got around to posting anything to the blog, but it does open a slot for me to back-post in a handy reference table.

The handy reference table is for the general opposite of what I was doing Thursday evening. Eating duck egg amuse bouche followed by courses that could have ended with a serious amount of chocolate (except I managed to side-step the pudding).

So my handy reference table comes courtesy of an article by two wheel blogs about cycling.

Some might know I've set up my bike with a gadget that stores various metrics that can be uploaded to spreadsheets and the internet. There's all the usual stuff about speed, pedalling rate and calories, but I thought it would be interesting to try out the extra measures (I'd call them proxy metrics) that show (a) how demanding a particular ride is and (b) what state it's left me in. I've been using trainingpeaks.com for this.

There's a measure called Intensity Factor (IF) as a way to show the difficulty of a particular session and the Training Stress Score (TSS) relates to the personal impact it will have and how long to recover.

There's loads of cleverness around all of this, but I'm more interested in figuring out whether one ride I do is measurably more demanding than another. One way I tell is by how clammy I feel by the end, but I thought it would be fun to play around with the numbers too.

Hence the simple ready reckoner, which gives me a sense of what is happening.

I thought I'd also post my current plots from when I started the current measures in January.
Performance Chart TSS and IF
It shows that I could ride a fairly short distance and it would seem like a fairly 'intense' ride. Through January the perceived intensity of individual rides started to lessen (see the blue dots dropping), presumably as I got more used to what I was doing. The actual loading of the rides varied somewhat (the red dots for each ride), but were mainly within a middle band.

The most interesting line is the blue one which is gently rising. That's supposed to be my general bicycling fitness, which does seem to be going up. Empirically that also seem to be the case because as an example I did around 18 miles this morning with relative ease. I'd have been spluttering a bit more a few weeks ago when I did this.

The pink dip in the middle of the range is a week when I was away somewhere and didn't do any cycling at all. It shows my residual degree of fatigue dropping until I restarted (it soon gets back to the same level though).

I'm doing this for fun, and don't necessarily have the charting model very well calibrated at the moment, but it sort of feels as if its saying the right kind of things.

I've also separately noticed that except for weekends I seldom cycle for more than an hour in one go. I'm thinking I should tip over the hour in the week now the weather and hours of daylight are improving.

If I can get it working properly I'll probably post an update, because rather than just counting miles and calories, this has some interesting potential.

For fans of detail, the amuse bouche evening is the second red/blue dot pair from the right hand end of the x-axis. Oops, do I see a small dip afterwards?

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