Several times on this blog I have talked about rowing telemetry and how I feel that Telemetry and power meters are the next big step needed to keep moving the sport of rowing ahead, but I have to admit that previously although I have read over the theory and background of rowing telemetry, other than a few short tests using a set up in an 8+ I’ve never really had the chance to really get involved in using it to properly analyse and review my technique. So over the summer I thought I’d put my money where my mouth is and organise a test row with a full telemetry system, specifically the telemetry system offered by Biorow and their new rental service.
Biorow are a major name in rowing Bio-mechanics, and if you’re not familiar with their free monthly papers on the subject then I would recommend checking them out here. Biorow also offers a wide range of devices for measuring how both you and the boat move through the water, but as I highlighted in an earlier post to get all the equipment it can cost quite a lot (upwards of £6,000 for a single at time of writing), however as mentioned, Biorow also offer a rental option, so that’s why one Saturday morning I found myself down at my club with Biorow strapping various sensors and wires to my boat, and furiously wishing I had properly washed the boat before they had turned up, and dreading the 2km piece that had been proposed in order to collect useful data from the test………
As mentioned there are quite a number of sensors that were attached to the boat and blades (and me!) so i’m going to go into more details about what they were using, here is also a flyer that goes into details of the sensors
This photo shows the sensors that were attached to my pin, long “arms” that are set on pivots and hook over the sculling blades inboard and track the movement and height of the blade through the stroke, so you can see how long you row and also how deep you plunge the blade into the water and how far you tap down and carry the blades above the water in the recovery.
This part is a tower that holds a sensor that has a retractable wire that is attached to the rowers back, and then from the extension and retraction of the wire it can track how your body rocks over during the recovery and during the drive. You can also see the large grey box which is the “brains” of the whole system and collects all the data from the various sensors, as well as contains the GPS to measure the boat speed and accelerometer for measuring the rate and boat pitch/check.
Moving on inside the boat, similar to the sensor for my back, there was also a retractable sensor which is attached to the seat to measure the seat position through the stroke, this combined with the back sensor means that you can work out how the legs and the backs are moving through the stroke (hopefully identifying if you bum shove or take the catch with the back).
Finally there are a set of strain gauges that are strapped to the blades (sorry no photo) in order to measure how much the blades bend through the stroke to measure how much force you apply to the blade every stroke.
This is me now all wired up and mid test!
Now to run the test you have a couple of options as to what session you want to run, if your aim is to try and be as fast as possible over a 2000m course then it might be worth doing a full 2000m piece with starts and all in order to see where work needs to be done, in my case I was more interested in getting a view on all parts of my rowing technique, so we ran set the work as a 2km piece at various rates to really see what I was doing at each rate, so the plan was after a racing start I would then drop the rate to 18 and then slowly work the rate up to eventually finish at free rate (36+), this would be a bit of a shock after my recent holiday and lack of time in the single! Below is a video taken a the end of the 2k where I switched from 34 to free rate
Following the testing all the data is downloaded from the system and compiled on a laptop to give you the final output of your data from the whole outing, after which they can then sit with you to go over the data collected (which I would thoroughly recommend)
To give you an idea of the data they collect, how it is presented and what you can gain from it I have copied some of the data below:
The first piece you go over is the overall summary of the pieces which is shown here and shows a general output of the piece that you have done, in this case it is the 2km that I did and split into each of the different rates that I did in the session, first of all showing in the first graph the number of strokes, variation in rate (i.e. how steady were you on rate) and the average speed you were going at that rate.
Next the force being applied in each of the different rates is shown, using the force that is being measured through the blade sensors, the efficiency of the blade through the water and the effective work per stroke
Next down the blue/red chart shows the rate and boat speed and also where the selections in the first table were taken
Finally on this page, you get to see the rate, boat speed, effective work and also the drag factor which is useful as if the wind conditions had changed during testing it would show up as a significant increase in drag and could help explain away any odd results.
The next slide starts to really get into the raw data that was taken from the session, showing the handle forces involved, how the boat pitched and rolled through the stroke, ad how fast my legs were moving down through the stroke and the recovery.
This is a breakdown of the part of the piece I did at 33-34spm (I also got the same for the rest of the rates but ill stay off overloading you with data and stick with this), here what they have done is show in more detail what is going on on average as I am rating 33-34spm, the main thing being you can see that my left and right arms are not apply the same amount of force per stroke, it appears that my right arms breaks early and apply’s the force first, after which my left arm then catches up and apply’s more force at the finish, so this is one point that I can work on
Finally this page is arguably the most useful, this presents the data at my race rate of 33-34 and compares it to the worlds best to see how I compare in boat speed, rate, force applied, boat handling skills etc and helps to show areas where I really need to focus on improving in order to get more boat speed, so below I have gone into more detail (as Biorow did with me) to explain what it shows and identify what I can work on to get faster.
So starting from the top, you can see the data suggests that if I raced a whole 2k as I did the piece at 33-34, then I would end up with a result of 7:32.7 (a little off the WBT),
Interestingly it then also shows the Prognostic speed at target rate, so if I rowed technically perfect, how fast I would be able to go considering the force/boat handling skills I presented, so it shows that even if I got no fitter, but working on my technique I could take 14 seconds off a 2k time which shows you how much improvement you can make with your technique it also highlights that my sculling arc is not as long as it could be (101 degrees rather than the ideal 114) so again that is an area to work on.
Next on the table the stroke arcs are broken down into catch and finish arcs and you can clearly see that my finish is around the right position, however I am short at the catch, therefore another point I have to work on is making sure I keep the length at the catch.
This can be confirmed by checking the blade height graph (pasted here again) which shows that I am not only letting the blade ride out at the finish (the target blue curve stays deeper for longer) but I am also skying slightly at the catch (two more things to work on), although on the plus side the initial catch and depth of the blade does follow the target rather accurately.
Next regarding the force applied obviously I am not applying enough force (more weights needed), but the main positive is that the peak of my force is in the correct spot (note the blue text), well done me 🙂
So in summary the main things I need to work on are:
- Being more equal with the force applied with either arm/making sure I don’t break the right arm first
- Ensuring I keep the length at the catch/don’t shorten up as the rate comes up
- Work on controlling the blade height at the finish and not wash out (one suggestion would be to add one degree lateral pitch to the gates so the blades stay in for longer)
- Stroke force needs to be improved
- Work on increasing leg speed off the catch
One final document that Biorow gave me relates to the video that was taken
This is a frame by frame breakdown of a stroke from the video, and what is particlarly clever is that if you look closely then you can see that each frame has a number, and that number matches up with the stroke profile graphs that have been presented earlier. That means you can see what you were doing to get the result that you see in the data graphs
For example, here are the handle force graphs that were shown earlier, and highlighted is an area where improvements could be made, as the force being applied “dips” slightly. However where in the stroke is that happening?
If you look at the chart on the left the x-axis is called Frame N which is frame number, meaning that the dip in force is happening between frames 22-28
So if we look at the corresponding numbers from the photos we can see that it is happening when my back is opening through the stroke, suggesting I may need to work on producing more force with the back, and it also looks like I break the arms a little early, another reason why the force may dip at this point.
In summary I thoroughly enjoyed the testing and plan to do it again over the season, although I would argue that almost all of the technical points raised are things that a good coach would see and instruct you to work on i.e leg speed (in fact the only main point I would say you wouldn’t be able to see is the force curve through the stroke),what I particularly like is the fact that you are being given absolutes rather than suggestions, so you have actual numbers that you can work on rather than just being told you need to get a little bit faster with the legs (but how much?!?).
Biorow’s offering in particular is also excellent as as well as being the only telemetry system that you can currently rent rather than buy (so you are talking £100 rather than thousands at this stage) they also have an extensive background in recording and analysing the data, and so are able to present these “targets” to you to compare with, this, in my opinion, is a real selling point as one major concern with having and using telemetry is that you could end up collecting a lot of information and then not be able to analyse it properly (an overload of information), with Biorow however the targets mean that its easy to see where you most need to focus your attention to get that extra speed you are capable of.