concept2

IMG_1255

Jan 2 2017

Happy New Year! – Ergometrics

First, I would like to wish all my readers a happy, healthy, and successful new year, without injuries, and full of quality training and successful racing.

I have spent the past few days in Berlin with the Roosendaal clan (my parents, my two sisters, the children and significant others). Of course this was more about sightseeing, visiting museums and attractions, and eating than about training. Still, one of the best ways of sightseeing in a busy city is an early morning run (Strava link).

Here are a few pictures:

Today, it was back to work. I spent the morning shaking hands and wishing my colleagues a happy new year. I kicked off a few things and around lunch time I took a break to go to the lake.

There is a thick layer of what looks like good quality ice there, and many people were ice skating. I have a slight cold, though, so instead of going on the ice I headed to the erg room of our rowing club.

Before doing a nice hour of steady state on sliders, I took a few minutes to video myself erging. For Christmas, Greg gave me a video analysis from Row Analysis, so today I happily taped markers on various places on the erg and on myself, and then made a ten stroke video. The raw result is here:

I hope the video is high quality enough for the analysis. I have uploaded it to the Row Analysis site and am now waiting for the results. Will keep you posted.

The hour of steady state was very nice. It is so comfortable to do this on an erg on sliders. It is easier on the back, and the stroke is longer (because you pick up the acceleration of the flywheel earlier in the stroke) and for me it is easier to hold a pace than on the static erg. If the row club had PM5 monitors for their ergs, I would work out there more often, even though the time lost driving there and back is not insignificant.

Edit

Adding a few video snapshots.

By • Uncategorized • 3 • Tags: , , , , , , ,

challenge

Dec 23 2016

Holiday Half Marathon

My last erg row of the Concept2 Holiday challenge. I thought about doing a full marathon, but I realized I have some other stuff I need to get done today. So just a HM. At Steady State pace.

I dialed up 21097m and just rowed free rate, listened to the radio, and took long water breaks at 14km and 7km to go. One great thing about rowing in the basement in winter is that the water gets nice and cool, and after a long row it tastes so good.


Workout Summary - media/20161223-1420110o.csv
--|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg
--|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS
--|21097|88:46.0|02:06.2|190.8|22.4|167.0|177.0|10.6
W-|21097|88:47.0|02:06.3|190.2|22.3|166.7|177.0|10.6
R-|00000|00:00.0|00:00.0|000.0|00.0|000.0|177.0|00.0
Workout Details
#-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS-
01|01000|04:04.0|02:02.0|186.7|21.1|136.7|152.0|11.7
02|01000|04:05.5|02:02.8|199.8|21.8|157.7|163.0|11.2
03|01000|03:55.4|01:57.7|202.9|22.2|165.2|169.0|11.5
04|01000|03:59.2|01:59.6|204.7|22.3|168.5|172.0|11.2
05|01000|03:58.0|01:59.0|207.6|22.7|171.3|173.0|11.1
06|01000|04:00.2|02:00.1|201.8|22.5|172.4|175.0|11.1
07|01000|03:58.3|01:59.2|206.8|23.1|174.8|176.0|10.9
08|01000|05:17.8|02:38.9|193.6|22.4|163.9|177.0|08.4
09|01000|04:03.1|02:01.6|195.0|22.4|173.0|175.0|11.0
10|01000|04:02.9|02:01.4|195.3|22.5|173.1|175.0|11.0
11|01000|04:02.3|02:01.2|196.7|22.9|174.1|176.0|10.8
12|01000|04:05.3|02:02.7|189.7|22.7|172.5|174.0|10.8
13|01000|04:03.4|02:01.7|194.0|23.1|173.2|174.0|10.7
14|01000|04:03.5|02:01.7|194.3|23.2|173.5|175.0|10.6
15|01000|05:22.3|02:41.2|175.7|21.9|160.6|173.0|08.5
16|01000|04:11.3|02:05.6|176.7|22.0|166.0|167.0|10.9
17|01000|04:09.6|02:04.8|179.8|22.1|166.8|169.0|10.9
18|01000|04:05.6|02:02.8|188.9|22.5|168.9|171.0|10.9
19|01000|04:06.0|02:03.0|187.9|22.6|169.3|171.0|10.8
20|01000|04:01.2|02:00.6|199.4|23.3|171.6|173.0|10.7
21|01000|04:44.2|02:22.1|138.2|20.8|154.5|173.0|10.1
22|00097|00:27.7|02:22.8|127.6|20.0|149.2|150.0|10.5

And here are the great pictures that tell you all about the row.

You can see quite clearly how stroke rate goes up and drive length goes down when I get tired. Not good.

By • Uncategorized • 0 • Tags: , , , , , , ,

myimage (47)

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.

By • Uncategorized • 0 • Tags: , , , , ,

IMG_1190

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.

By • Uncategorized • 5 • Tags: , , , , , , , ,

myimage (40)

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.

By • Uncategorized • 2 • Tags: , , , , , ,

bokeh_plot (71)

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.

By • Uncategorized • 1 • Tags: , , , , ,

myimage (32)

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

By • Uncategorized • 0 • Tags: , , , ,

«< 12 13 14 15 16 >»