Wednesday, August 13, 2008

Running Index / Stride Lenght charts @13August

for the "Polar" maniacs...

I extracted these 2 sets of data from the Polar SW and might deserve some remarks..

a) Running Index (the red line is the rolling average of 20 points)
I already showed this chart some months ago with an explanation.
Polar website explanation on the Index here

After 3 solid months of conditioning, the chart is going in the right direction. It is remarkable that I am getting very close to the same levels as my peak form last season, and it is still summer.

Definitely this function of the Polar SW is worthy to keep under watch every month or so to understand the actual trend of the form. There is a quite close correlation between the trend of the Running Index and the actual performances in races.




(Note for Polar PPT users: use the function "report" and later "edit/copy to clipboard". You paste the data to Excel and create this chart)



b) Stride Length Average


This chart leave me rather puzzled...
It seems that in my peak form, the stride got the longest (it makes sense), but I am really perplexed about why it is now declining so considerably in the part 2-3 months, regardless of the remarkable increase of fitness (as shown by the RI above)...
Might be "too much" base training, not enough speedwork, with loss of strength in the legs? I really invite for comments from the readers...

5 comments:

running faster with the ALIEN LIZARD said...

Hi,
i think i read that you found a new route through the countryside a couple of months ago, is this on a uneven dirt path if so this could explain your shorter stride but at the same time increase in fitness?

by7 said...

thanks for the comment.
Actually I do not run every day on that dirt road. Because of the torrential rain this Summer, I had to run mostly on concrete/black top while I am in Dongguan, while I ALWAYS run on black top if I am in Hong Kong. I did a similar chart for the cadence (to be published tomorrow) and it shows a steady increment over time. So it seems that I am running with shorter stride at higher cadence, overall with higher speed. But I am curious to see what's happen when the temperature/humidity drops to a more reasonable level...

running faster with the ALIEN LIZARD said...

iT WOULD BE INTERESTING TO KNOW WHICH IS MORE EFFICIENT LONG STRIDE OR FASTER TURN OVER?
coming from a cycle background i followed with great interest how 7 tour De France winner LANCE ARMSTRONG changed from a slow big gear pusher to a smaller gear, fast peddler! he improved greatly both in time trial and in the mountains.HE WENT FROM 85-90 rpm up to 100-110 revs
Ive heard that for running 90 strides a min works best, what do you think?

by7 said...

We all read in Jack Daniels' book about the 90rpm as "ideal". In other publications, I read some criticism on this statement because it also depends on the individual style and the height of the runner.
For sure the best runners have legs spinning much more than us, mortals...
Therefore I take the 90rpm more as a "guideline" to reach than as my ideal target...

Simone said...

What software did you use to do the graphs?

I'm harvesting the Polar software features and I get something but not exactly that, and specifically not the stride lenght and cadence over time!!!

Did you move the data manually to another software?

by the way in my last 2 marathons the average cadence was about 94-95-96 I'm pretty sure that is increasing from my previous marathons. These two marathon are also my 2 best performance and with the high average heart rate. So I consider that increase of cadence as an improvement, probably now I should lose a bit of weight to increase the stride length while maintaining the cadence.

In my last marathon the stride length was 146-148cm for the first hour, then was always going down, 135 after 2hours, 130 at 2h15 then I finished around 125cm in 2h41 ... that was for sure the fact to be tired, but I'm surprised to see this reduction already from the second hour of the race.