Return to site

The Quiske Cloud

Data Analytics for Rowers

Quiske includes a web portal where rowing data can be analyzed in detail. The cloud service allows rowers to drill into their data in detail, and coaches to compare rowers within their crew.

You need a cloud subscription to upload and analyze sessions recorded with the Quiske Rowing App. With the subscription you can also export the data for your own purposes (see below).

How does it work?

Record your rowing (by pressing Start inside the Quiske App), and once you're ready press the back button to go back to the main screen and then press the folder icon. From there you can upload any of your recorded sessions. All sessions will then be listed for you in the portal. Click on any individual session to see the summary overview of the workout, including distance, time, number of strokes, pace boat type etc.:

The workout summary includes basic info such as total distance, number of strokes, type on boat (in this case a M4-), the placement of the pod (if you were using one) and a workout map

Below the workout summary is a graph showing the strokerate and boatspeed over the full workout duration. From here you can choose different regions for closer analysis by painting over the areas your interested in:

The summary graph of the session shows the stroke rate and boat speed over the whole workout. From there you can select regions for closer analysis, such as here two different regions at different stroke rates have been selected, blue SPM 35 and green SPM 22

The areas you choose are analyzed and displayed below in corresponding colors. You can toggle to draw the multitude of individual strokes or look at the calculated average stroke from within each region (the latter is recommended!). Below the boat acceleration graphs from the above two regions : The blue region constains 11 strokes at SPM 35 and the green region roughly the same number of strokes at SPM 22 , both regions are translated into one average curve for each region:

The boat acceleration graph at two different stroke rates in a 4-. Blue is the average curve at SPM 35 and green is the average curve at SPM 22. The time is normalized and stretches out the acceleration graph across the axis.

The boat acceleration depends not only on the strokerate but also on the crew and the boat type. In this guide we won’t go through how to use the web portal in detail (there’s a video here) but we’ll next dive into how you can compare the technique of different rowers within a crew.

Synchronizing crew technique

To maximize the speed of your boat you need not only a committed crew but must also align the rowing technique. Rowing in the most efficient way requires perfectly synchronized strokes within the crew. More specifically the timings of catch and finish, drive and recovery and the seat movements of individual rowers in the same boat need to match.

With detailed post-training analysis of measured data you can find differences in the timing of the main sequences that the stroke consists of: the catch, the drive, the finish, and the recovery. After differences are identified in the portal, the instant feedback of the Quiske Rowing App can be used to help rowers align their technique while training on water.

The Quiske Cloud can help data-savvy coaches synchronize crew technique. The data from each individual rower can be uploaded and overlaid and compared with all the other rowers within the crew. The portal was designed specifically to allow coaches to compare technique within their crew, but the tool is new and we are keen to hear feedback and suggestions on how to make the tool easier and more intuitive to use.

As an example, let’s look at the phases of the rowing stroke measured at the same time from the right oars of two rowers (green and blue) in a double. Below is the angular oar velocity during drive (positive) and recovery (negative).

The oar angular velocity curves of two different rowers in the same crew. There are differences in the timing of catch and finish

The angular velocity is positive when the blade of the oar is moving in the drive direction and it is negative during recovery. The catch is defined as when the direction of the oar changes and as you can see from the above graph catch in this case happens not exactly at the boat acceleration minimum but slightly before it. The oars are already moving in the driving direction at the point of maximum deceleration, but the blade catches water properly only after this, as can be seen from the change in the gradient of the oar angular velocity during the early drive, at that point the angular velocity continues increasing but is doing so slower. At finish the oar angular velocity decreases quickly and changes direction to go into recovery (during recovery the sign of the oar angular velocity is negative, i.e. it is moving in a direction opposite to the drive direction).

When overlaying the oar curves of the rowers in a crew you can see whether the motion of their oars is synchronized and if they row with the same technique.

You can also look at how synchronized a crew is by comparing the seat data from different rowers in a crew. Read more about this in the free Guide which you can download on the main Quiske webpage.

What's the point?

Quiske can provide data on boat acceleration as well as seat and oar technique: the boat acceleration and the seat motion graphs help rowers ensure they’re letting the boat slide under them during recovery so that they won’t upset the flow of the boat. The seat data also helps a rower focus on making a fast and strong push with their legs. The oar graphs help with the handling of the oar, the speed of hands away and the full shape of the oar flight path (horizontal and vertical angles). It is also interesting to compare the full angle that each rower is able to maintain at different stroke rates during a session. Should the rower move their hands quickly away or pause the oar for a small moment after extraction? This is a matter of taste but it is crucial that everyone in the crew row the same way.

The comparison of rowers is done after the training session in the web portal. However, rowers and coaches can use the portal to decide on the right targets. After that decision is done, the instant feedback of the App can be put into use to help rowers nail those targets, every stroke. The rower can choose to see graphs of oar angles or seat speed or to see simple numerical metrics which might be easier to digest while concentrating on rowing. For example, the instant feedback on the stroke angle can help the rower make long strong strokes, consistently. The App can also show the maximum seat speed during each drive, helping the rower focus on pushing hard with the legs, every stroke, even during long sessions.

The coach can also use the data in the portal to help put together the most synchronized crew in terms of technique-based facts. In the past choosing the rowers for crews may have had quite a bit of uncertainty. Having real facts on performance on water makes also crew selections more objective and fair.

The analyzed data is and remains the property of the rowers, and even when they change coaches or clubs they can show their history in technique through the cloud service. Rowers can share/unshare their data for analysis to any number of coaches, enabling also remote coaching. This also opens up new business opportunities for professional coaches around the world, allowing coaches be a more shared resource among a larger number of rowers. The metrics can also act as a kind of translator between older experienced coaches with their wealth of silent knowledge and younger rowers accustomed to measuring themselves and having data to back up claims and prove progress. The metrics can corroborate the statements by the coach, the measured facts can act as a bridge of understanding between the coach and the rower.

Coaches will always be needed. A talented coach can see subtle things, but many of these things can be read from the measured data and graphs. The pods can tirelessly measure and analyze your every single stroke, which means that once you know the ideal stroke profile you’re aiming for you can get help from the instant feedback and work to make your every next stroke better.

Summary of the data available

Finally, a summary of the main graphs in the Quiske cloud:

  • The boat acceleration and the boat speed 
  • The oar angular velocity 
  • The blade flight path, the full horizontal and vertical movement over the period of one stroke
  • The seat speed graph

All of the graphs visualize rowing performance during the period of one stroke cycle. The stroke cycle runs from the negative acceleration peak to the next and all graphs measured from the same crew at the same time can be compared with each other since the data is synchronized according the same boat acceleration. Even when comparing rowers from different crews it is insightful to compare data from different boats measured at the same stroke rate.

The boat acceleration, boat speed, oar angular velocity and seat speed can be placed on top of each other to see how the timing of the phases of the oar or the seat correspond to a particular boat acceleration or speed. All these examples were measured from the same rower in a W4- crew at 35 SPM.

The quality of the data...

...depends very much on how the phone and pod are mounted to the boat. The phone must be rigidly fastened to the boat so it doesn't wobble during rowing, otherwise the boat acceleration data (which is the basis for the stroke detection) is wrong. Also, the Quiske pod has no calibration, which means that utmost care must be put into the positioning of the pod. If the orientation of the pod is wrong the data won't make any sense. A way to make sure the pod is correctly aligned on the oar is to check that the blade flight path is flat during recovery. Check the correct pod positioning here. 

Hidden gem: The Quiske Rowing Data can be exported!

This is something we haven’t talked about much, but we should : The data in the Quiske cloud can also be exported so that you can further process it by self service as you want. If you’re a coach into data analytics this might interest you !😉

The Quiske algorithms provide the rowing data neatly organized into individual strokes. This readily analyzed data can be exported by email and we’ve also integrated exporting to Rowsandall Analytics.

What does the exported data contain and what’s the format ?

A rower or his/her coach can download the Quiske “per stroke” data in CSV-format for further analysis. This allows you to generate completely new insights from the measured data.

The export file is organized into lines which contain the following column headers with these data points per stroke: Time stamp (sec), meters (m), SPM (strokes per minute), speed (m/s), latitude, longitude, stroke angle (deg), max drive speed (deg/s), max seat speed (m/s), max seat recover speed (m/s). Additionally the file contains detailed data from within each stroke (in-stroke data points) containing the boat acceleration curve, the oar angle velocity curve, and the seat speed curve (assuming oar or seat were measured).

The Quiske Rowing data can be expored for self service analytics

The data export functionality is free for anyone with a Rower or Coach subscription to the Quiske portal. At the moment data export is only available for on water rowing data (indoor rowing data cannot be exported).

Even if you don't own a Quiske pod the Quiske App data can still be very valuable since there's a lot to be learnt from just the boat acceleration graph which is available without the Quiske pod. We think the pioneering work of Rowing in Motion explains this quite well. We do, however, recommend investing in a Quiske Pod, to also get insight into oar/seat technique ;-)

Happy Rowing,

Quiske team

All Posts
×

Almost done…

We just sent you an email. Please click the link in the email to confirm your subscription!

OKSubscriptions powered by Strikingly