rowing

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Dec 21 2016

Short Steady State and stroke video attempt

The plan was to do 20km of steady state. I didn’t even get to half way. I woke up early after a short night, and there is so much stuff to do before Christmas.

So I did a 5km at steady state pace. Heart rate way to high and perceived effort as well.

Then I tried to film myself in order to reveal something about my stroke force profile.

And here is the video. I am afraid I don’t have a better quality right now.

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Dec 20 2016

The mysteries of the force curve

For OTW rowing, I am not even convinced a force curve should be looked at independently from boat speed and acceleration. On the other hand, wouldn’t it be great if we could extract a few meaningful parameters from the force curve to help analyze technique?

The approach Nielsen-Kellerman have taken is using “Slip” and “Wash” parameters, which basically tell give you a reduction in effective stroke length. Slip is basically the stroke length (or oar angle difference) it takes to get to 100N of force from the catch, and Wash is the oar angle difference (or stroke length) near the finish at which the force drops below 100N. The figure shows this well (from the brand new “stroke profile” plot on rowsandall.com).

Schematic Stroke Profile from an NK Empower Oarlock

It turns out that the schematic stroke profile is pretty close to the real one. When I calculate the area under the curve and compare with the average stroke force, there is pretty good consistency.

The ratio of average/peak force is a value between 0.5 and 1, the latter value just being a theoretical upper bound for a perfect block shaped force profile and the former the value for a triangular force profile. My values are pretty consistently around 0.57, but Greg Smith’s values are significantly higher (above 0.65 if I remember well).

So in the name of science, I did the following experiment on the erg. I must say using Painsled for iOS made it very easy to capture stroke profiles. I rowed a just row 150m off, 10 strokes “on”, varying stroke rate between 20 and 36spm. During the “on” strokes I tried to row what I consider good technique. Immediately after the 10th stroke, I grabbed the phone, did a screen capture, and took a picture of the PM5. I went up to 36spm, and back down, to see if there was consistency.

Before I show you all the raw data, here are the aggregate plots made on Rowsandall.com:

As you can see, my Average/Peak force ratio correlated positively with stroke rate, being 0.56 below 24spm, and 0.60 above 32spm. Drive length was pretty constant. I didn’t see a difference between going up the ladder or going down. Work per stroke correlated positively with the stroke rate, as did both average and peak force.

So here are the raw data, one set of stroke rates per picture gallery:

20 spm

24spm

28spm

32spm

36spm

The graphs from Painsled show the last stroke of the set of ten in bold, and a few of the strokes before in a lighter line. The pictures of the PM5 show the final stroke. I was struck by how different the pictures look from the graphs, but I guess that’s an effect of the vertical scaling.

I will have to think about this a bit more. Here is a link to the article by Kleshnev who has numbers between 0.5 and 0.6, with 85% of the rowers at the higher end.

I guess the next step will be to film my stroke.

At the least, I think this post is a good demonstration of the power of a good data analytics site, combined with the excellent erg data capture of Painsled.

Post Scriptum

Discussing the stroke profiles, Greg and I made the cumulative plots of the Average/Peak force ratio on rowsandall.com. Here are the two plots. Interesting to see the differences.

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Dec 20 2016

Dirty Dozen and One More

Another week where I allow myself one Anaerobic Power workout. Today, I repeated the 13×45″/1′ workout of last week. After that, I did something special to capture stroke power curves, but more about that in the next blog post.

Here are the rowsandall.com plots for this workout. It was hard work. Somehow, I didn’t have the energy to go deep.

The workout editor has a little difficulty getting the averages right for these short intervals. On the PM5, I saw around 220-225 meter for the full 45 seconds, so I believe below statistics are underreported.


Workout Summary - media/20161220-1850090o.csv
--|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg
--|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS
--|05159|22:45.0|02:12.3|241.0|26.4|164.6|179.0|08.6
W-|02796|09:45.0|01:44.6|335.1|29.2|163.8|177.0|09.8
R-|02376|13:00.0|02:44.1|141.1|23.5|166.5|177.0|02.5
Workout Details
#-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS-
01|00228|00:45.0|01:38.5|341.2|30.8|138.5|162.0|09.9
02|00215|00:45.0|01:44.9|333.4|28.7|161.6|170.0|10.0
03|00214|00:45.0|01:45.2|348.6|28.6|166.8|174.0|10.0
04|00218|00:45.0|01:43.0|348.8|29.6|164.3|174.0|09.8
05|00217|00:45.0|01:43.8|347.3|29.3|164.0|175.0|09.9
06|00216|00:45.0|01:44.3|336.7|29.8|165.0|175.0|09.7
07|00223|00:45.0|01:41.1|342.2|29.4|169.1|176.0|10.1
08|00220|00:45.0|01:42.2|322.2|28.9|167.1|175.0|10.2
09|00209|00:45.0|01:47.6|307.7|28.2|165.2|173.0|09.9
10|00216|00:45.0|01:44.2|339.3|29.3|167.0|175.0|09.8
11|00209|00:45.0|01:47.8|321.2|29.2|167.0|174.0|09.5
12|00207|00:45.0|01:48.6|316.9|28.2|166.6|174.0|09.8
13|00205|00:45.0|01:49.9|351.3|29.8|167.2|177.0|09.2

However, a week ago I had more than 200m less, so apparently I worked harder today!

Click on the images to open the gallery. Also, according to the images, I did 15 Watt more.

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Dec 18 2016

Sinner Man

This famous 10 minutes song by Nina Simone is part of one of my go-to playlists for long erg pieces. I always cheer up when this song starts, because I know the next 10 minutes will go by in a blink. It is really good erging to this song.

And the repeated call for “Power”, where Nina probably didn’t have erg power in mind, is a good reminder of what rowing is about.

Today I did 4x5km at one minute rest. I played a bit with stroke rates following the 1000/750/500/250m sequence that is my favorite of this fall.

Measured lactate after 15km: 1.7 mmol/L.

Measured lactate after 20km: 1.8 mmol/L.


Workout Summary - media/20161218-1120080o.csv
--|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg
--|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS
--|20300|86:20.0|02:07.6|187.1|20.5|157.8|169.0|11.5
W-|20000|82:21.0|02:03.5|189.2|20.5|158.0|169.0|11.9
R-|00303|04:00.0|06:36.4|129.3|20.4|152.6|169.0|00.8
Workout Details
#-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS-
01|05000|20:37.1|02:03.7|184.5|19.6|150.0|165.0|12.3
02|05000|20:20.9|02:02.1|193.0|20.3|162.1|169.0|12.1
03|05000|20:28.2|02:02.8|190.1|21.1|161.5|168.0|11.6
04|05000|20:54.9|02:05.5|189.3|21.0|158.5|166.0|11.4

I didn’t row the last interval slower. It took 58 seconds to do the lactate testing after interval #3, and I sinned and took a drink and another 20 seconds rest before I set off for my final 5k.

The now officially released version of Painsled, (link to iOS App Store) behaved well, except for one small glitch. Even though in the settings I have not activated Sync to Strava, when hitting “Export” in the app, it exported my workout as a “ride” to Strava.

I had to delete it there, because when I take the route through Rowsandall.com, the stroke data are exported better (leading to more meaningful graphs on Strava), and the session is exported as a row, not as a ride. Otherwise, I strongly recommend this excellent app for anybody who rows with a PM5.

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Dec 17 2016

A short, long run

A view on the lake from the rowing club. Yes, that is ice.

Time for the weekly running event. It was -6C when we started out, three of Romana’s girls/women and I.

Unfortunately, we ran through a part of Google Earth with two very different satellite images

We ran along the lake, and then near the castle we took a right turn into the forest. We had a fairy-tale like view on the castle. Something like this. The trees were frozen as in the picture, but there was no snow on the roof:

Running through the forest, we encountered many deer, which was good because the girls started to be tired and spotting the animals was a good distraction.

Only at that stage I found out that Zdiška had been on the rowing club since 8am, doing an erg training that she had missed during the week. So she did a hard interval workout (the Pete Plan Pyramid) followed by a 14km run. Wow!

We finished the run in good spirits, despite one girl having a painful blister, so all was good.

https://www.strava.com/activities/804288506

For me it was a slow run. Not too long in kilometers, but long in time.

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Dec 14 2016

Getting rows on Strava

Two days ago, I intercepted a question on Greg Smith’s blog Quantified Rowing. It turns out someone was looking for a way to convert ErgData CSV files to TCX or FIT, in order to upload his workouts to Strava, had found my rowingdata Python package, and had trouble installing.

I pointed him to rowsandall.com, the website that is running rowingdata as one of its elements and is able to import your C2 logbook rows and share them with Strava, without you having to install anything.

The next day I received a thank-you email from Joakim, the happy user. Also, he had been kind enough to write a positive review on his personal blog. And I was even more happier with Joakim’s remarks that the site works well for visually impaired people like he, using a web reader. Wow! I must confess that I haven’t taken access for the visually impaired in mind when I developed the site.

Tuesday’s row was a 18km of Steady State. I rowed it as 6km/5km/4km/3km at 18/19/20/21 spm.


Workout Summary - media/20161213-204248-20161213-2030100o.csv
--|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg
--|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS
--|18278|75:56.0|02:04.6|186.0|19.8|158.4|171.0|12.1
W-|17250|70:18.0|02:02.3|190.8|19.9|158.9|171.0|12.4
R-|01028|05:38.0|02:44.6|112.3|19.1|146.8|171.0|09.9
Workout Details
#-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS-
01|06000|24:39.5|02:03.3|185.0|19.0|149.8|163.0|12.8
02|04750|19:25.8|02:02.7|189.9|19.6|162.2|170.0|12.5
03|03750|15:10.9|02:01.5|194.3|20.5|164.6|169.0|12.1
04|02750|11:02.0|02:00.4|200.4|21.4|165.6|171.0|11.6

I did some 250 m of paddling and a drink pause between the “intervals”, so I used rowsandall.com’s interval editor to get that into the statistics (and remove the paddle strokes from the plots).

Not really concentrated on hitting 18spm, and to be honest the stroke rate drifted to 19spm in the first interval

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Dec 12 2016

Mixing in some ANC

ANC Today:

No, not this ANC

I am starting a 3 week mini meso-cycle, substituting one steady state session for an interval session. ANC stands for Anaerobic Capacity. Short intervals at 2k speed or faster, with enough rest to recover and not make it a hard distance row. The idea is that you row at a pace that is hard but sustainable for a large number of these intervals, and you can go faster if you want (but you don’t want to).

First, I did this month’s CTC:


Workout Summary - media/20161212-201119-sled_2016-12-12T20-02-36ZGMT+1.strokes.csv
--|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg
--|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS
--|02492|10:01.0|02:00.7|271.4|30.3|166.4|179.0|08.2
W-|01537|05:00.0|01:37.6|371.9|31.9|166.2|179.0|09.6
R-|00955|05:01.0|02:37.8|115.5|27.5|167.5|179.0|07.2
Workout Details
#-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS-
01|00151|00:30.0|01:39.3|352.6|33.1|127.8|158.0|09.1
02|00205|00:40.0|01:37.6|371.2|31.5|165.8|172.0|09.7
03|00256|00:50.0|01:37.7|373.8|32.7|170.7|177.0|09.4
04|00307|01:00.0|01:37.7|373.5|30.7|173.1|179.0|10.0
05|00257|00:50.0|01:37.3|379.2|31.6|171.9|178.0|09.8
06|00205|00:40.0|01:37.6|374.5|31.9|170.8|176.0|09.7
07|00156|00:30.0|01:36.2|370.0|32.6|168.7|176.0|09.6

The graphs:

That CTC was not enough for a full training, of course. So after picking myself up from the floor, I dialled up a 45″/1min time based interval workout and set off. The first interval was actually the hardest.


Workout Summary - media/20161212-2005230o.csv
--|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg
--|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS
--|04630|22:45.0|02:27.4|224.7|26.9|164.1|180.0|07.6
W-|02559|09:45.0|01:54.3|317.3|29.5|163.2|178.0|08.9
R-|02082|13:00.0|03:07.3|131.5|24.6|166.0|178.0|01.6
Workout Details
#-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS-
01|00220|00:45.0|01:42.1|305.4|30.3|144.5|161.0|09.7
02|00211|00:45.0|01:46.4|312.0|29.1|161.8|168.0|09.7
03|00213|00:45.0|01:45.6|322.9|29.1|164.6|171.0|09.8
04|00212|00:45.0|01:46.2|314.7|28.6|164.6|172.0|09.9
05|00207|00:45.0|01:48.9|321.3|29.5|162.1|172.0|09.3
06|00216|00:45.0|01:44.1|316.9|29.3|166.6|174.0|09.8
07|00216|00:45.0|01:44.0|311.2|29.0|165.1|174.0|10.0
08|00217|00:45.0|01:43.7|333.4|29.8|166.6|175.0|09.7
09|00208|00:45.0|01:48.0|313.5|28.7|165.7|174.0|09.7
10|00210|00:45.0|01:47.0|314.7|29.3|164.1|175.0|09.6
12|00213|00:45.0|01:45.5|331.0|30.6|162.2|176.0|09.3
13|00214|00:45.0|01:45.1|336.7|30.8|169.2|178.0|09.3

Interesting to see that I am much higher in work per stroke on this workout than on the steady state.

It was nice to row this. When I closed my eyes during the workout, I could imagine being in my single and racing in Munich, first 10 strokes out of the starting pontoon. That memory also made me sit up straight and pay attention to rowing a good “OTW” stroke and rhythm.

A good workout.

Tomorrow: Steady State.

This week is supposed to be a heavy week, but I already know now that it will be difficult to do the planned training time, with a business trip in the middle of the week.

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