# Friday – 12.5km Steady State / force curve

Friday was a bridge day between a Bank Holiday and a weekend. I decided to take a holiday and catch up with some maintenance on the site, as well as preparation for a workshop on Monday. I ended up taking more time on the website, and will have to prepare the Monday workshop today.

At the end of the afternoon, I descended to my rowing cave. First I played a bit with the official Concept2 smartphone app “ErgData”, and then I reverted to my beloved Painsled app to crank out a 12.5km steady state. I wanted to do more, but I ran out of time.

Here are a few new plots. I am still looking for the “signature” set of plots for a workout.

I have added a new metric to Rowsandall.com. It is the ratio of the average drive force vs the peak drive force, and it tells you something about the force curve. For a perfectly “flat” stroke profile, this ratio would be 1.0. For any sort of triangular profile, the ratio would be 0.5. The higher the value, the longer the force plateau during your drive. It seems from the plot above that I am pretty constant throughout the 19 to 22spm stroke rates I rowed in this session.

Here is a study by Kleshnev on the force curve in rowing.  Here is a key plot from the study. “Classical style” would give you a force ratio close to 0.5. “Simultaneous style” is significantly higher (looks like 0.7 by eye). Kleshnev is not making conclusions on what is better. It is interesting that the tables in the study show force ratios between 0.4 and 0.6, but not much higher, for the rowers that he has in his database.

This plot shows work per stroke and power output. The average power was 174W (yes I have added annotations to the plots), and the work per stroke was 600 J. However, the plot clearly shows that it is dropping slowly but steadily during the workout.

Stats:

``` Workout Summary - media/20161118-1610052o.csv --|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg --|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS --|12508|52:38.0|02:06.3|174.0|19.7|151.3|163.0|12.0 W-|12508|52:38.0|02:06.3|174.0|19.7|151.3|163.0|12.0 R-|00000|00:00.0|00:00.0|000.0|00.0|000.0|163.0|00.0 Workout Details #-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS- 01|02500|10:23.6|02:04.7|178.3|19.3|141.9|153.0|12.4 02|02500|10:24.5|02:04.9|180.0|20.2|150.5|159.0|11.9 03|02500|10:37.6|02:07.5|169.1|19.3|150.2|159.0|12.2 04|02500|10:29.1|02:05.8|176.2|20.3|156.0|163.0|11.8 05|02508|10:43.9|02:08.3|166.5|19.5|157.6|162.0|12.0 ```

The short URL of the present article is: https://wp.me/p7rJSt-1Jx