Pacing analysis vs the fast riders

Aside: my Power2max power meter was delivered today.  But, I can’t fit it yet 😦  I was advised by Power2max that I could re-use my existing chainrings, but this is not the case, they do not fit.  So I have to order some new chainrings, which is going to cost an additional £180!

Anyway enough moaning.  I want to discuss pacing, in particular the pacing of the time trial I rode on Saturday.  Via the wonders of Strava, it’s possible to see the data from the other riders who have ridden the course and uploaded their data in the past.  You can see the specific course here.  It would be interesting to compare power figures, but since I did not have a power meter, and neither did any of the fastest riders for the course, I’d have to rely on Strava’s power estimation.  I know from experience that this is wildly inaccurate and so almost completely useless.  So the next best thing, to get an idea of how hard riders were pedalling, is heart rate.  Perhaps in looking at the heart rate traces of the fast guys and comparing them to mine, I might be able to see where they are trying comparatively hard, compared to me, and so it might give me some ideas about where to push and where to hold off.  Of course, a faster rider is a faster rider, but I’m told there is a lot of free time to be gained in pacing, and so of course I want to take advantage of that.

The data, if correct, is illuminating to say the least.  The following 5 images are the HR traces of 5 of the top 6 riders who have uploaded to Strava.  The top guy finished almost 5 minutes ahead of me.  Might as well be a year.  On each image, the green line represents the terrain, the red line is their heart rate.
PCC_6 PCC_4 PCC_3 PCC_2 PCC_1The 6th fastest guy is at the top, the KoM (king of the mountain) is at the bottom.  The 5th fastest rider had no heart rate data, hence he is missing.  The actual numbers don’t mean anything, because of course everyone’s heart beats at a different rate.  What I’m interested in is locations of the peaks and troughs that would indicate where the riders are pushing, and where they are taking a rest.  From my reading on time trial pacing, I’d expect that people would put a little extra effort in on the uphill sections, and ease off on the downhill sections.  This is what I had tried to do.

But the lines don’t really contain peaks and troughs of note at all!  With the exception of the 3rd placed rider, they are notable for their flatness.  Now let’s take a look at my trace:

PCC_meDoesn’t take a genius to see the difference, does it?  Heart rate is all over the gaff.  In general you can see the places that I am trying harder do coincide with the uphill sections of the course.  In isolation, I was quite happy that I’d managed to ride like this, given all the things that are going on around you.  But the question has to be asked, why aren’t the faster riders doing this?  I have to assume that they’re not just fitter than me – they’re more experienced and know how to pace a TT.  The most telling place is what happens at the beginning of the big hill, just before the 8 mile mark.  Believe me, this is a hill.  But for 4 out of the 5 other riders, their heart data barely registers a blip.  I don’t see how that is possible on a hill like that unless you slow right down.  So I drilled down into the data.  The top rider’s speed dropped 14mph on the first part of that hill.  My speed dropped 10mph.  I remember having a terrible time for the next minute or so as a result of that sprint.  For the second part of the hill, my speed bottoms out again to the same minimum as on the first part.  But the fastest rider’s speed drops down to 3mph faster than was ridden on the first part of the hill.  All this, while suffering almost no variation in heart rate.

My suspicion is that these guys are riding almost the whole course on the limit:  they know exactly the level of exertion they can cope with.  Hardly any of them show any peak in heart rate at the end of the course, which indicates that they were not flat-out sprinting, presumably because they had nothing left.  Of course I have no real idea what level is my maximum, because I don’t have the experience.  Must practice!

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Posted on April 2, 2013, in Events. Bookmark the permalink. Leave a comment.

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