May 8 2017
In this post I am looking at a few detailed metrics of the Masters 1x 1000m race I rowed yesterday. Data were collected with a SpeedCoach GPS 2 combined with a NK Empower Oarlock.
Here is the overview plot of catch and finish angles for the entire outing, including warming up and cooling down. The actual race starts at 1200m. Interesting to see that I seem to suddenly take length about 400m before the finish line. This is exactly the point where I finally passed my opponent and actually started to row at a lower power.
Here is a close-up of catch and finish angle for the race segment. We’re talking a 1 degree difference, but still it looks pretty consistent and significant.
So here is the power and average drive force. The start strokes are always at high power and force, as you are starting from a stop and rowing short strokes at high rate. I think I did a pretty good job getting the average force down to an average value and holding that for the rest of the race. It is interesting to see the power drop about half way, while the drive force remains constant, and the catch angle actually increases. That means that I either started to row at a lower stroke rate, or the actual stroke was shorter despite the catch angle being longer.
The plot thickens when we look at the “Work per Stroke” which drops with the drop in power. So it looks like the stroke rate remained constant, but something else was changing.
Funny enough, both the absolute drive length and the effective drive length remain constant for the entire race and at pretty good values. So the shift in catch angle was actually me focusing on length (after I had passed my opponent) and tap-down (which makes the stroke slightly shorter at the finish). Should be visible from Wash values.
Looking at Wash and Slip values, I cannot see a big difference:
Finally, the solution to the riddle seems to be the Peak Drive Force:
Interesting! I hadn’t expected that. The stroke profile plot for the first half of the race:
And here is the second half of the race. Almost identical to the first half, but the tiny difference do lead to a drop in power, while my pace didn’t drop as much as that of my opponent.
Here are power and pace in one plot:
And finally, stroke rate and power:
Monday – Tourism and travel home
Today was a holiday, so we made a few stops on the way home. Here are a few pictures: