rowing

May 3 2017

Technique in the coxless four and the new Stroke Analysis plot

Technique in the 4-

Wednesday. The day when the CVK Brno Masters group tries to gather at 6pm and row the eight. Today, there was hope until 4pm. Then, there was an email that one of us had to urgently go to Prague for work.

In the end there were six of us. And it was raining hard, so “Pazdy”, who is recovering from a back injury, didn’t want to row outdoors and chose the indoor rower. I announced that I want to row something else than the single, so in the end “President” took the single, and “The mouth”, “Turkey”, “Bulldog” and I rowed the coxless four. We did mostly steady state but we tried a few 15 stroke intervals at a higher rate/pace. The intervals were not so good, but after we did a few minutes of square blade rowing and alternating square blade/squaring we finally got a bit of boat run.

Revamped Stroke Analysis plot

Today, I revamped the Stroke Analysis plot. This chart is similar to the “flex chart”, the Swiss Army Knife of rowsandall.com’s charting capabilities. Just as with the flex chart, you can chose any metric for the X axis and two other metrics for the Y axis. The difference is that the Stroke Analysis plot doesn’t relate to a single workout, but instead it plots all strokes for a certain time period.

That functionality has been part of rowsandall.com for more 8 or 9 months, but I restricted it to erg workouts. Today, I have added a selector where you can chose the workout mode (water, rower, slides, skierg, snow, etc) and added OTW rowing related metrics.

To show what is possible, I have plotted all rowing strokes between March 1 and May 4 and created various Stroke Analysis plots. Because I use Empower Oarlock related metrics, the data are self-selecting for the single. If you row a lot in different boat types, you will see them all in this plot. In the future I will build a boat type selector so you can filter focus on one discipline.

I also filtered out all “paddle” strokes by selecting strokes at 500 J/stroke and higher.

The effective length seems pretty consistent across the various stroke rates. If anything, I may have a slightly longer stroke at 30spm, and above that the length seems to decreate again. When looking at this metric in the boat, I like to see 90 degrees and higher.

Slip, a measure for how quick I load up the blade at the catch. This metric is clearly lower at higher stroke rates.

Catch angle vs stroke rate. I wonder what the group of strokes at the lower value is, but I suspect it is before I moved the footstretcher.

Wash, a measure for how long you keep the load on the blade before the tap down. Lower values are better. I have started working on this in the course of April. So if I select data from the second half of April to today, it should be better. Let’s check:

Hm. I guess there is work to do.

Finish angle. Again, there is a mix of footstretcher settings in this plot.

Work per stroke. Here I do include “paddle” strokes.

Average drive force. I seem to pull a little harder at the higher stroke rates.

And finally – the peak force angle, i.e. the angle at which I reach the maximum force during the stroke. Most of the data are centered in a 10 degree wide range around 25 degrees (before the pin).

And here is, finally, a power vs pace plot:

I have to adjust the units for pace. Currently, they are in milliseconds per 500m. Of course this plot is not normalized for head or tailwind, but still it is interesting.

How to use the Stroke Analysis

As with many things in data driven rowing, there is not a single answer to this. We are only starting to discover what is possible, and are exploring possibilities rather than focusing on what is useful. Still, I can imagine a few ways to use these data:

Think of the graphs as a fingerprint of a certain rower.
It will be interesting to see how the graphs vary between rowers.
Perhaps they can be used to do a first selection of matching rowers for a double or quad.
Look at time evolution of the graphs for a single rower.

Finally, above I have mostly put the stroke rate on the x axis. However, when you use Power instead, the graphs seem to start to make much more sense, even if you include “paddle” strokes. Just an observation.

For Wash, I know quite well what the blob above 20 degrees is. These are steering strokes where I reduce the force on my starboard scull.

Looking forward to discussing and finding more use of these plots. Please explore and share your thoughts.

By sanderroosendaal • Uncategorized • 0 • Tags: 4-, lake, OTW, rowing

May 2 2017

Steady state in the single – working on tap-down

Arrived at the club early but had to wait. My daughter Lenka was out in the single.

I rowed this session together with Martin. I was slightly faster, at slightly lower stroke rates. Happy about that. I kept an eye on the “wash” metric during the entire row and worked on technique to keep its value low.

Today, I have released a few innovations on rowsandall.com. One of them allows you to write annotations in the Flex plot:

As you can see, I made good use of it. The feature was suggested by Greg from Quantified Rowing and I immediately recognized it as a great idea. It greatly improves the workflow when you can capture your thoughts immediately when you create the plot. There isn’t too much you can write about a technique/steady state outing, so the comments on the plots are a bit “empty”, but you get the point.

I also played around a bit with the video editing software DashWare to get it to properly use rowing related metrics. You can read the how-to here. The result:

By sanderroosendaal • Uncategorized • 1 • Tags: lake, OTW, rowing, single, steady state, technique

May 1 2017

Monday: More race pace training

It’s a Labor Day in Europe and in this part that is a bank holiday.

The training plan that the coach sent didn’t take into account the fact that I am racing in 5 days, so I had to improvise a bit. But Thursday’s workout looked interesting.

3x(7x40sec/20sec)/5min at race pace

I woke up into a nice sunny day, but the trees were moving and the wind forecast wasn’t great, predicting 7 to 8 m/s, which on our lake means it may be a bit rough. The forecast was confirmed when I arrived at the club. So I decided to just cross the lake to Rokle and then take the river to Veveri Castle and beyond.

I got a little bit of water in the boat while crossing the lake. I am afraid it didn’t really look like rowing in this part, but the goal was just to cross. It was a little choppy, really:

On the river, I did the workout. I had to improvise a bit. Some of the turns are a bit sharp, so I took the rest instructions as “inspiration” and adjusted the rest and work intervals to suit the turns.

This is a great training. Perhaps I should have increased the stroke rate a little, because it wasn’t as hard as I expected, but this was difficult on the river, with the turns, the wind, and the other traffic.

The need to watch the traffic and steer made it a bit hard to watch “Wash”, but I think there were a few intervals where I had the right emphasis.

The average “wash” value at 28spm and higher is 13.6 degrees, but if you look at the dots (each one being a stroke), you can see that this is skewed a lot by steering strokes and I would argue that I am closer to 12 degrees.

Here are “wash” and “effective length” vs stroke rate. I don’t think it makes sense to look at the averages. Crossing the lake twice, I had to revert to short strokes. There was no way I could do something that looked like rowing in those conditions. Also, after I finished the third interval, I paddled quite lightly, just enjoying the scenery.

And here is the video. I took the FIT file from the SpeedCoach and just did a quick DashWare overlay using the power, cadence and pace values. The averaging causes the metrics to change very quickly at times. Wouldn’t it be cool to be able to overlay Empower Oarlock metrics like slip, wash, catch and finish angle over the video? I guess you would have to do a slightly better job at synchronizing than I did, though:

By sanderroosendaal • Uncategorized • 0 • Tags: chop, intervals, OTW, river, rowing, single, training

May 1 2017

Friday – Sculling with the breaks on

Friday

The training plan asked for 6km with a break (a band around the single to slow down the boat), followed by 5km without.

Rowing with a band is fun. It slows down the boat just enough to make it easy to concentrate on the stroke sequence. It was a chilly 4 degrees C, and a bit windy, but not much chop, so it was actually a quite nice day to row.

Interesting to see how the power measured varies much more in the first part (with the break on).

After removing the break, I kept the stroke rate low and tried to focus on technique. Still, Wash values were all over the place.

Saturday + Sunday

No training. We had to drive 2 hours to Ceske Petrovice. Romana’s aunt was celebrating her 80th birthday, so it was a big family event in a cottage in the Orlicke Hory (“Eagle Mountains”). Quite remote place.

What was rain in Brno, had been snowing in the mountains, so when we arrived it was interesting to see the remains of the snow.

We spent the evening talking (and drinking) in the cottage, so we also needed Sunday morning to rest. By the time we got back to Brno, I didn’t really fancy getting in a workout. Let’s say that it was a hard weekend, anyway.

By sanderroosendaal • Uncategorized • 0 • Tags: band, break, lake, OTW, rowing, sculling, single, steady state, training

Apr 27 2017

Thursday morning – 36 intervals in the single

From a rowing technology blogger’s standpoint this was really a session I was looking forward to.

It wasn’t to be. Sometimes the NK SpeedCoach’s user interface drives me crazy. I am 100% sure that I have recorded the row, but somehow I have managed to delete it on the device, perhaps when I switched it off. Anyway, when it was time for me to sync the unit with the PC, I was surprised to see no new session.

It’s really a pity, because this morning’s session was:

6x(6×15 strokes “on”/10 strokes “off”)/5min, with the 15 “on” strokes at 26, 28, 30, 32, 34 and 36spm.

The idea was really to learn (again) to row at high stroke rates and to transfer boat feel and stroke efficiency from the 26spm all the way up to 36spm.

I set the SpeedCoach to show power, stroke rate, effective length and wash during the row and all the time I was looking forward to doing the data analysis. I wanted to see how wash and effective length, as well as work per stroke, would hold up at the higher rates, and uncover other hidden information from the data.

So if I want to row a 1k race at 320W and 32spm, probably all my strokes should be around 10W/spm, i.e. I should row the 26spm bit at 260W, the 28spm bit at 280W, etc. This is what I tried during the row.

It was a cold and rainy morning. Four degrees C, and something between snow and rain when I drove to the rowing club. When I launched, the rain had stopped, and it turned out to be a gray and cold but fantastic morning.

The swallows were heaving breakfast, and it was a joy to see them. At these temperatures, they fly just above the waves, about the same height as a rower’s blade between strokes, and they are such fantastic flyers. I really enjoyed how efficiently they glide through the air, only occasionally reverting to high wing frequency flying, when hovering to catch insects or gaining speed in headwind conditions. I made a mental link to my rowing, doing the 26spm as the swallow glides and the 36spm as it hovers.

As said, I failed to save the session on the SpeedCoach, so you will have to do with the pictures from the Garmin watch, imported through Strava. Strava magically added some power values through a biking/running plugin, so you shouldn’t take those too seriously (although the values are pretty good). The SPM values were all over the place but that is because the Garmin tried to measure running cadence.

Sets 1, 3 and 5 were rowed in tailwind. Sets 2, 4 and 6 were rowed in headwind. As the sets progressed, I became better and better at hitting the right Power values and I think I learned a lot from this session, even though it almost feels like I didn’t do it, not having any data.

With the swallows and all, definitely a session I enjoyed a lot. It was hard, it wasn’t short, but it was 100% worth it.

By sanderroosendaal • Uncategorized • 1 • Tags: ANC, ANC training, lake, OTW, rowing, single, training

Apr 27 2017

Wednesday – a row in the coxless four

Wednesday is our Masters evening. Of course the Masters rowers of our rowing club do more trainings, but on Wednesday at 6pm we gather and row in the eight.

On this particular rainy and cold Wednesday evening, the turn-up was 5 rowers, and a sixth one called us at exactly 6pm, saying that he was “just now” leaving office. That office being just 45 minutes away in the peak hour traffic. 🙁

To at least do something that resembles rowing in an eight, we decided to pick a coxless four. The fifth guy decided to stay on the erg and wait for the sixth guy.

I rowed in bow seat, and the rest of the crew consisted of Martin “Krocan” (=Turkey), Petr “Bulda” (=Bulldog) and Michal “Míša” (=Bear). So we had a rich representation of the animal kingdom.

The boat was an old Empacher 4-, and we lost 15 minutes because we had to replace the shoes so that Bulda would fit into the boat.

I didn’t really fancy rowing on the bow seat, but I guess being the lightest of this crew (with 75kg, compared to Bulda’s 113kg), it had to be me. I like practicing my sweep rowing, but it takes more of my mental effort to do it well, compared to sculling. You can imagine that I did not have the need to also turn around every few strokes and scan the lake for upcoming traffic. Well, so be it.

All our boats are foot steered from the stroke position, so at least I didn’t have to do the steering. And Míša is one of our rowers who can steer our lake with a blindfold, so the course was always right and I just had to watch out for the traffic.

This was a technical training, so we did a lot of drills.

Some of the drills involved rowing with stops at various places. You can see that the SpeedCoach didn’t really understand that.

It was cold and rainy, but we did make a lot of progress during this short outing. It was fun to row something else than a single, and it had been a long time since I last rowed a coxless four.

By sanderroosendaal • Uncategorized • 1 • Tags: 4-, coxless four, lake, OTW, rowing, training

Apr 25 2017

Masters: Pacing a 1000m single scull row with a power meter

So according to Rowperfect, I am “on a mission to find the optimal pace when doing head races”. I liked that. I like being on a mission.

I am already on the next mission. The 1k sprint season is starting. Since the head racing, I have lost some fitness, mainly due to me not putting in the required training volume. Work. Other stuff.

So, I don’t know exactly where I am, fitness wise. A week and a half from now I will row my first Masters 1k race in the single. It would be good to have a few tries in before that. And now that I have a power meter, I can use it to help me pace the race.

Here is my line of thought:

Start with the erg power value as a guideline. I estimate my current erg power for a 1000m (around 3:20 time) to be between 325W and 350W. On the water, everything is slower, so the race duration is longer, so I expect to end up a little lower. However, it is not given that the Empower Oarlock power values correspond exactly to the erg power. Anyway, it doesn’t matter.
If I go out too fast, I will finish slow. If I go out too slow, I should sprint to the line to get the power average as high as possible.
Make use of all of rowsandall.com’s data analysis power to find out as much as possible about how I did that initial 1k.
Next time, row at the average power I achieved and use the lessons obtained in 3 (hopefully).

I made use of a gap in my schedule, after lunch and before the evening conference calls. It was a warm afternoon, a slight drizzle, 15 degrees, and flat water. Only a light wind, which turned out to be a headwind for my 1k.

I did a 3km warming up including two practice starts and a few 10 stroke bursts:

At that point I was in the buoyed 2km track, about 800m from the finish line. I mentally prepared myself for “a lot of red” (referring to the power and heart rate plots), dialed up a 1k on the SpeedCoach and got into starting position.

Workout Summary - media/20170425-150809-Sanders SpeedCoach 20170425 0311pmo.csv --|Total|-Total-|--Avg--|-Avg-|Avg-|-Avg-|-Max-|-Avg --|Dist-|-Time--|-Pace--|-Pwr-|SPM-|-HR--|-HR--|-DPS --|01000|04:00.0|02:00.2|319.3|30.2|175.4|184.0|08.3 W-|01000|04:00.0|02:00.4|318.5|30.1|176.1|184.0|08.3 R-|00000|00:00.0|00:00.0|000.0|00.0|000.0|184.0|00.0 Workout Details #-|SDist|-Split-|-SPace-|-Pwr-|SPM-|AvgHR|MaxHR|DPS- 00|00100|00:22.9|01:54.6|365.1|33.0|140.6|167.0|07.9 01|00100|00:23.9|01:59.5|339.1|30.0|170.6|172.0|08.4 02|00100|00:23.5|01:57.4|341.9|29.9|175.0|178.0|08.5 03|00100|00:24.0|02:00.1|328.9|30.0|179.9|181.0|08.3 04|00100|00:23.9|01:59.3|326.2|30.0|181.8|183.0|08.4 05|00100|00:24.0|01:59.9|321.1|30.2|182.8|184.0|08.3 06|00100|00:24.1|02:00.3|311.2|30.0|183.1|184.0|08.3 07|00100|00:24.5|02:02.5|294.0|29.8|182.4|183.0|08.2 08|00100|00:24.9|02:04.7|287.6|29.5|181.8|183.0|08.2 09|00100|00:25.2|02:06.1|276.6|29.1|181.0|182.0|08.2

So yes, I went out too fast. But I did obtain an average power value, and it’s 320W. As usual in a 1k row, around the 500m mark things started to fall apart. I really had trouble keeping the stroke rate at least above 30spm (where I should be at 32spm in a couple of weeks), and in the slight headwind everything just became very sluggish. I was happy though that the total time was not too far from 4 minutes. Usually, in April, my 1k OTW time is around this, and today it was into a headwind.

Below, I will add some detailed discussion of the various other metrics.

I paddled the 350m to the finish line of the 2k course, turned the boat, and continued in a light “steady state” row. During that steady state row, I did two 250m pieces, just for the fun of it, to test how 320W of power would feel at 32spm. I did one piece in tailwind where I saw 1:55-1:56 pace, and one in headwind where the pace was around 2:00.

Detailed analysis

Catch angle seems high. When I first started rowing with the Empower Oarlock, I was worried about the short catch angle. Perhaps I have no the opposite problem? It seems to be an artifact of the sprint pace. The average over the entire outing is 66 degrees catch, 41 degrees finish. What you can also see is that as I got tired in the second half of the test, I shortened up on the finish. Here’s the “stroke profile” plot:

I did not watch “Wash” numbers, and not having rowed a lot in the single lately, I am a little behind on my “mission” to improve my “wash” numbers. I think I could do better on this value. Here is the story of “wash”:

Yep, it became a sad story after 700m.

Work per stroke varied quite a lot during the row. The mean value was 648J (which is high), while the 25% and 75% boundary was at 593J and 678J respectively. So that means that more than 25% of the strokes (about 30 strokes) were at more than 678J, and about 25% of the strokes were below 593J.

For head racing, I wanted to be around 550W, and I think that is even a good value for sprint racing. At least, that’s my hypothesis, still to be confirmed. For now, I note that I should rate up and lighten up.

This graph (above) of power and average drive force vs time is the embarrassing one. Of course the start strokes were strong, but then I brought it down to what I thought was a good value of just under 350W, but in the headwind, after 500m, you can see exactly where the wheels came off and I reduced the average drive force, shortened up at the finish, and brought the entire power down. At this point in the race, I was looking at my power values and I didn’t know what to do. (Unfortunately, I had no additional metrics to see. Being “smart”, I had set one of the bottom screens to distance, not realizing the SpeedCoach defaults the other bottom screen to distance as well when doing pre-programmed pieces. I wish there was more control of that. I would like to set it exactly as I want it, not as NK thinks I want it.)

Oh well, I also dropped the rate in the final 200m. Booh, Sander!

Here are the two “250m” pieces that I did afterwards.

Of course these were shorter pieces, but they did feel better. I think I have a plan for my upcoming 1k race.

Also, I am still impressed by how incredibly useful these metrics are in analysing what happened, and how, if you put in a little thinking, they guide you to what is hopefully a better plan to attack the next 1k piece.

By sanderroosendaal • Uncategorized • 2 • Tags: 1000m, 1k, lake, masters, OTW, rowing, single, sprint, training

«< 36 37 38 39 40 >»

rowing

Technique in the coxless four and the new Stroke Analysis plot

Steady state in the single – working on tap-down

Monday: More race pace training

Friday – Sculling with the breaks on

Thursday morning – 36 intervals in the single

Wednesday – a row in the coxless four

Masters: Pacing a 1000m single scull row with a power meter

Calendar

Tags