Today I finally had the chance to take the Stryd Duo and Footpath to the track. Having tested these new features last week on grass and pavement, I was eager to see what differences there might be on the track surface. I was also eager to see what differences there might be when running different directions on the track.
After warming up and mobilizing, I did one easy lap around the track anticlockwise (typical track direction) – 3:00 and 249W – and then one in the opposite direction – 2:56 and 252W. My metrics were about the same as on grass and pavement (slight imbalance left/right), except that my Ground Contact Balance was 50/50 on the track (both directions).
Below is my Stryd Footpath visualization (side view) for the anticlockwise lape (solid) and clockwise (dashed):
Consistent with my grass and pavement runs, my left stride is more compact than my right going both directions. I had hypothesized that the left and right stride sizes might be inverted when going the opposite direction on the track, but that turned out not to be the case.
Looking at the top view, though, you can really see the directional difference:
Here you can see clearly that both my strides bias to the left (outside) when I’m running clockwise. The same effect is visible from the back:
This is why I try to run both directions on the track as much as possible, to work my legs in a much more balanced way.
After my easy laps, I ran a 10-minute all-out run that was part of my training plan (anticlockwise – typical track direction). I made it just shy of 2km (5 laps) with 356W average power. This is hard for me to admit, as, even just a few years ago, I was running faster than that for many consecutive kms as part of long, easy runs. There are no two ways about it: I am out of shape.
Regardless, the 10-minute run provided interesting data to compare against the easy laps. There was no major change in the metrics, but you can see the difference in stride length below:
One interesting phenomenon in this comparison is that, for my easy lap, my left stride extended out as far as my right stride. However, for my faster five laps, my left stride actually extended farther than my right. Let’s see how that looks from the top view:
Wow, look at that significant asymmetry between left and right during the faster laps. I’m not sure if that is attributable just to running faster, or to the curvature of the track. It would be an interesting experiment to run at the same power going the opposite direction and compare the geometries made. Actually, it would be interesting to run the same power going straight too.
The view from the back tells basically the same story:
Actually, if we zoom in on the back view, we can see a very interesting phenomenon. Here I’m looking at just the first curve (solid) vs the first straight-a-way (dashed):
Wow, look how different the kinematics of curve running are from straight line running. In road races or cross country, these differences may not be that important but, in track, curves comprise 50% of most race distances! I have no idea what to do with these data yet, but having them at all is a great first step.
I have long been interested in more tools to help me at the track, because most tools – including Stryd historically, have been more geared toward longer-distance running. The new features of Stryd Duo and Footpath are a huge step (no pun intended) in the track and middle distance direction. Today’s brief runs were just the tip of the iceberg, but I look forward to more experimentation – and at greater intensity – soon!