NK Empower wireless oarlock rowing power meter review

After announcing they were working on a power meter last year, NK have now released their empower oarlock onto the market bringing a power meter that promises to be accurate, easy to use and – most important of all – affordable. I have been using mine for the last few weeks and so feel it is a good time to outline my thoughts – both the positive and the negative and also some thoughts of where I hope to see NK go with the product over the next few months and years.

If you’ve bought anthing from NK recently then the packaging will probably be familiar to you with their simple but effective plastic bag holder – saves having to break out the scissors!

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Inside the bag we have the empower gate itself, the magnetic plate (for measuring catch and finish angles), plastic inserts to help the gate fit snugly on your pin, the calibration tool, manual and in my pack some NK stickers.

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The NK gate itself is clearly larger than a standard gate but not overly so, the bulk itself is mostly in the back of the pin where the sensors and battery pack live.

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Generally this extra bulk at the back could be an issue for a bow rigger, and NK have a useful table that shows compabaility for most of the boat manufacturers out there – and yes, my single is a Fluideisgn which means the gate wouldnt fit….this isn’t a major issue however as NK have worked with Fluid to produce C-Cups that are larger than the standard ones, so luckily for all you fluid owners you also get your own special installation step.

Installing the gate

NK have a useful video and I have also noted my own installation findings.

Comparing the two C-Cups you can see the new one is considerably roomier

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One new C-cup installed, second to follow

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Now with the new C-cup as they are longer it will mess up your footplate position and also your span, so you have to re-adjust your span and also move your feet. Now the cup is around 3cm longer than the old ones

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So you can either move your rigger around that much to keep your boat trim the same, or you can move your feet one hole which is around 3 cm as shown.

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Now install the plastic washers into the gate and slot onto the pin with the magnetic plate below, make sure there are no washers between the gate and the magnetic plate.

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Now you need to make sure the plate is straight to make sure your angles are correct its recommended to get a long straight edge and line it up across both pins, making sure that it is at 90 degrees to the centreline of the boat.

Once done, tighten with the hex key. And with that, youre installed! Next you need to calibrate the gate

Pairing the Empower gate and the GPS

Again – more useful videos from NK

Firstly go into your speedcoach settings and setup,

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then go into “Accessories setup”

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“Oarlock Setup”

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Now you will see the following screen, currently blank as you are not paired.

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Press the enter button again and you will see the following screen and you select connection

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And now pair.

Now press the button on the side of the oarlock and it will begin to flash green slowly until it connects when you will see this on the screen and the oarlock will show a solid green.

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Note that you only have to do this pairing once, once they have been paired the first time then the speedcoach will remember and in future once you turn on the oarlock the speedcoach will automatically spot and pair with the oarlock without you needing to do anything.

A cool thing to note is on the pair page now where you move the gate you can see the angles change in realities like below

however the angles are not calibrated yet so that leads us to….

Calibrating the Empower gate

Even more NK Videos!

Going back to initial setup – in this setting pages it’s a good idea to clarify the blade lengths and inboard (essential for working out power as it has to know how much leverage you have on the oar to calculate your power) as standard its 288/88 but if you don’t have this then adjust, zero the force on the gate and then next zero the angles.

To do this, take the natty oarlock tool

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And fit it to the magnetic plate as shown making sure that A and B are at the top to begin with

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And select “zero angles” on the GPS

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The speedcoach will take you through the calibration

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Complete!

And now you’re getting accurate angles and are ready to boat

Note that the manual mentions you should occasionally calibrate both angles and force, this is pretty normal for power meters as outside conditions sometimes mean the values “drift” over time. A quick calibration can make sure that the numbers stay accurate.

In use the gate is impressive in its simplicity, as mentioned once you have calibrated it initially then it will automatically connect to that same speedcoach once it has been turned on, so it really is as simple as turning it on and away you go – if you are familiar with the speedcoach GPS then you will be immediately familiar with setting up the various screens on the speedcoach to show your data – except now you can also see

  • Catch Angle
  • Max Force Angle
  • Finish Angle
  • Force
  • Slip
  • Power
  • Wash
  • Average Power
  • Stroke Length
  • Work per Stroke
  • Effective Length
  • Avg Work per Stroke
  • Max Force

The NK GPS allows you to select up to 4 different screens in the classic view which showing any combination of the above which I find most useful during a workouts or you can set a detailed screen which lets you focus on a singe technical point like angles – better for technical outings

Why is training with a power meter important?

There are many advantages to using a power meter over a heart rate monitor or rowing on ‘feel’ – it’s for good reason that a power meter has become the most popular training tool in cycling after all!

The main advantage is that using a power meter takes out all the guess work involved in estimating how well you are rowing. With a power meter on your boat, there is a quantitative number that tells you exactly how much power you are putting out – or, in other words, how well (or badly) you are going – in short, a power meter doesn’t lie, whereas heart rate and boat speed can be affected by a number of external factors, such as fatigue, hydration, wind, stream and temperature. By using power you are seeing exactly how hard you are working and how well you are propelling the boat.

One thing to note – it’s not proposed that a power meter replaces a heart rate monitor – its best to use both since they are actually telling you different things. Power is the input of effort to move the boat and Heart rate is a relative figure which measures your body’s response to that effort. Using a heart rate monitor and power meter together will allow you to see how your body is responding to training.

Downloading your workout
Once you have finished your outing the workout will be recorded on the GPS – you can extract it from the GPS either by the android/ios app  or via windows or MacOSNote that at the time of writing if you export via a mobile app then the data file doesnt include the data from the empower gate (e.g. power, angles etc) – this is being worked on by NK at the moment and will hopefully be corrected soon. Exporting by Link means you end up with a .fit and a .csv file – the reason for two files is because of the challenges around support for rowing – currently all the main training sites have rowing as an “extra” sport and is not the main focus, so they don’t include the concept of rowing metrix like force curves and catch angles – to get around this the GPS produces two files

  • the .fit file which is formatted to be is fully compatible with all the main training log sites out there at the moment in the same way as .fit files are for cycling – so like cycling you get cadence, power, GPS route etc and all that information

strava page

  • the .csv file which a complete list of all rowing metrix in one place – not recognised by most sites out there but luckily one site is and that is rowsandall which has been configured to display the rowing specific metrix for your review

rowsandall curve

There are some points that are worth highlighting that are outlined in the FAQ on NK’s site

  • NK have used Bluetooth to connect the gate to the monitor – although this is a widely used connection method, it does have the drawback that it is only capable to create a 1:1 connection between the master and slave device – by that I mean that a gate can only broadcast to a single screen – if you think that through then it means with the current gate and GPS it is impossible for a coach and a rower to see data at the same time from a single gate, or even two people in a pair seeing each others power output at the same time.
  • The Empower gate cannot display a force curve either during the outing or from the data at the end of the workout – the closest you can see is a rough “curve” using the data points of the catch and finish angles and the peak force angle – NK does justify this however as they point out “Even after years of looking at and coaching with force curves, there is still no agreement on what makes a “good” curve” which is a solid argument
  • For scullers – Currently you can only use a single empower gate with a single monitor, you cannot connect two gates to a single monitor – i’m not aware of a technical reason why it wouldn’t be possible gates to a single screen over bluetooth but until this is activated this means the same drawbacks of a single side power meter in cycling apply to the empower gate and if you have a power imbalance (which most of us do) you may get incorrect power readings as your gate is doubling either your weaker or your stronger side to get the average power – again this is justified by NK as it cannot be that larger otherwise you wouldn’t go in a straight line! But again its worth paying attention to
  • Currently  I am seeing occasional drop outs when using the gate with a bluetooth heart rate belt which requires the NK GPS to be powered off and on again to reestablish connection and this has been confirmed by at least two other users – I have found that not connecting a HR belt to the GPS keeps the Empower connection stable  and I know NK are aware and are working on a fix
  • Wear could be an issue over time -the all in one build is excellent as a waterproof/lifeproof device, however over time I would see the plastic parts that come in contact with the blade would wear which would eventually mean it would need to be replaced – it will be interesting to see if NK could replace the plastics for you or if you need to buy a whole new gate?
  • Currently the GPS only allows 4 panes of data – personally I would like to be able to see some more since some points are better in context – for example catch angles, finish angles and overall angle are related but to see them all you would take up 3 panes – better to either have one pane scroll through the data points or have catch and finish on the same pane as the overall but smaller so it’s easier to see all in one
  • Price – the elephant in the room is price – at £600 for the empower gate and £389 for the GPS you are looking at nearly £1000 all in – on paper a lot of money but genuinely adding power to your training is the number 1 best way to improve your training efficiency and make sure that you are getting the most out of your workouts on the water as I have discussed before and how others have discussed before  – and remember that in cycling £1000 is common for a power meter so NK have actually done well to hit a lower price point with their empower gate despite the lower potential market – and compared to other power meters available today it is priced very well.

Conclusion

All in NK have produced a great piece of kit in the Empower oarlock, producing a power meter that’s easy to install, use and export the data for analysis – yes there are a few drawbacks currently, particularly the minor bugs mentioned above (although I have no doubts they will be fixed) – but NK has finally made an affordable power meter available to all,  and in my mind is the first thing that someone should buy if they are looking for something to help them reach their maximum potential.

 

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Posted in Biomechanics, Gadgets, Rowing software, Rowing Telemetry | 4 Comments

C2 static watts vs NK Empower Oarlock watts – A personal comparison

Just a short post on some findings using the Empower Oarlock – I am working on a review and I promise I will try and get it out as soon as possible! In testing the gate I had been wanting to compare two  equivalent workouts on a concept 2 ergo and the water to see whether it is possible to use the information on one to use the other – for example if you have set training wattages on the erg, could you use the same wattages on the water? To test this I decided to run a common FTP test to see how each compares to the other.

For those of you that aren’t aware of FTP (functional threshold Power) – it is basically an invented value that is described as the power that you are able to hold for an hour, and is closely correlated to a 4mmol blood lactate level (read about lactate testing here) but as it doesn’t require the costly blood testing method so is a cheap way of getting a similar result and to then be able to set training zones.

A workout for an hour flat out doesn’t sound like much fun however, and so in cycling it is common to run a 20” test and to then use 95% of the power for your FTP – rowing however is slightly different, I don’t know about you but I know my 6K score and my hour score are not 95% of each other! More commonly its around 80-85% and so one recommendation is to do a 20” at rate 20 and use 100% of that value to get your FTP.

Below is the table which shows the outcome of the two tests

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As you can see I averaged 30 watts more on the water than on the erg which I wasn’t expecting – the conditions for the water workout were challenging (head wind and chop) so I thought I would see an impact on power with me battling the conditions as well as the workout, also interestingly other users of the Empower gate are seeing lower values on the water than they are seeing on the erg

https://twitter.com/RodSiegel/status/831184158609190912

As a side note the difference in wattage between on the water and on the erg that I am seeing is a similar value to the difference I used to see when I was comparing rowperfect and static ergo scores – so using lactate testing an sticking to 2mmol I would see 20-30 watts more on the dynamic than the static

Conclusion

It is too early to conclude what this means as of yet – just from my data and Rod Siegal’s it does seem to suggest that the comparability between the empower watts and ergo watts varies person to person so you can’t use training zones set on the erg on the water (and vice versa), it would be recommended to run the tests on both to work them out.

EDIT: another thing to add is that as I am sculling and the NK is recording one side power only (bow side in my case) and then doubling it then this could be skewing the results I favour if the water session – i.e. If I am putting more power out on bowside then I could be getting a false high result for the overall

My previous experiences do seem to suggest that the rowperfect may be a better tool for hitting the same watts as you would see on the water. Of course the only way to test this is to repeat the 20 min test on the rowperfect….. great….

Posted in Biomechanics, Rowing software, Rowing Telemetry | 12 Comments

ErgIQ review – connecting your PM5 to your Garmin watch

ErgIQ is an app that has been developed to run in conectIQ – Garmin’s app development software – and let’s you connect your Garmin watch directly to your PM5 monitor to directly record data to your watch for uploading to Garmin connect. The app itself is still in Beta and you can read more about and interact with the developer in the forum.

To install the app – make sure that you have a supported Garmin device and that your PM5 is updated to the latest firmware – personally I am using the Garmin Vivoactive HR which as I reviewed earlier is currently one of the best GPS watches for rowers available and is available on amazon for £179.99 at the time of writing.

To install – go to the Smartphone app and click on the connectiq store

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Now search for ergiq

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And the app will install to your device once you next sync and when you open the app you’ll see this screen

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To run the app, first set up your PM5 so it is ready to detect the Garmin. Select more options

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Then select turn wireless on

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Your Garmin will connect by ANT+ so press connect with Ant+

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Now on the Garmin you should see a pair request which lists a 4 digit number which is the last 4 numbers of your monitors serial number.

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One you press yes you will see the same screen as when you opened the app on your watch, but now it will say “row” in the top left in green

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And now you’re ready to go! Note that you don’t need to press start or stop or anything – just program the workout into the PM5 and then once you are done and you press menu on the PM5 then the Garmin app automatically ends and records the workout. Workouts are recorded on one continuous feed as well so even during “rest” parts of intervals it is still recording your HR (providing you connected your chest belt to the PM5) and wattage.

As with any workout now when you next open the Garmin app you will see your workout – however you will notice the data is unusual

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Trust me I took more than 12 strokes this workout!

The issue is with the level of access that Garmin allows developers – at this time connectiq apps are not allowed to record data to the main Garmin fields – instead they have to record the data to Connectiq fields instead, and if you go to the more detailed data in the app (second tab) and scroll down you will find it

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And in the graphs tab

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This is great for connectiq – however not if you want to share your data to other training sites like Strava as they don’t recognise the connectiq data – so you get heart rate and cadence data however therefore details power are all blank.

strava

EDIT : it’s worth noting that it’s possible to link ergIQ and a smartphone app to the PM5 at the same time as a nice backup – so ErgData or PainSled at the same time as ergIQ – nice!

Summary

In Summary then – the app works really well for its intended use of getting your rowing power data into Garmin Connect – once you have loaded the app and connected it to the PM5 its completely hands off in logging the workout and then automagically uploading it to Garmin Connect which is brilliant – however it is less good if you want to do something else with your data…. sadly due to the current restrictions meaning the app can’t record to the main data fields and has to use the ConnectIQ fields instead that means the essential power data is blank when the file is synced elsewhere like strava – making it only as useful as the standard indoor rowing app Garmin comes with anyway – and that has less steps to perform when running the apps.

Therefore I would have to say if you are only interested in putting data into Garmin and you have access to a PM5 then this app is perfect, however if you have any interest in copying the data elsewhere or you have a PM4 or earlier then ergIQ currently cannot help until Garmin allow the correct fields to be updated – and you should look to options like Painsled uploading directly or ergdata uploading through Rowsandall as your best options.

Posted in Biomechanics, Gadgets, Rowing software, Rowing Telemetry, Smartphone Software, Training | 5 Comments

Other sites using TRIMP for rowing

Adding on to the post yesterday on the StravistiX – Sander has updated his blog with a post talking about other sites that use TRIMP and comparing his data across a number of sites – worth a read!

Over on RowingMusings (read that blog!), a recent post discussed Stravistix, a Chrome plugin to add some stats to Strava. The most interesting add-on is a Fitness & Fatigue graph, based on the TRIMP measure of your training load. SportTracks and TrainingPeaks also have something similar implemented. The PC version of SportTracks has a plugin that…

via Using Fitness, Fatigue and Training Load graphs — Rowsandall

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StravistiX – A Strava plugin which can help with rowing

StravistiX is a chrome plugin for your Strava account that lets you track your workouts over time and gives you an idea how your fitness/fatigue is changing over time. How does it do that? Well it basically uses your recorded heart rate and uses it to calculate your Training IMPulse or TRIMP. TRIMP was originally developed by Dr. Eric W. Banister and basically it represents the amount of heart stress during an activity: the longer you go at full throttle during an activity, the more TRIMP of activity goes up.

The nice part of this is that although TRIMP was originally created for running, it has been shown to also work for weight lifting, cycling etc – essentially any sport including rowing AND the plugin is completely free (although the author welcomes donations!).

But what does it do? Well when you load the plugin it scans your Strava data and then shows you a graph of your TRIMP for all the days you have workout data – It looks quite confusing at first but it is actually pretty simple.

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Training results in both a positive and a negative effect – The positive effect is called fitness, and the negative effect is called fatigue. Fitness and fatigue can combined to provide a value of form or Performance.

The graph shows three lines

· the orange is your fitness and that is a long term view of your training over the last 42 days

· the black is your fatigue and that is your short term training load over the last 7 days

· the grey is the difference between fitness and fatigue and is used to judge if you are training the right amount to get fit without burning out which is called Form

  • +25 < Form : Transition zone. Athlete is on form. Case where athlete has an extended break. (e.g. illness, injury or end of the season).
  • +5 < Form < +25 : Freshness Zone. Athlete is on form. Ready for a race.
  • -10 < Form < +5 : Neutral Zone. Zone reached typically when athlete is in a rest or recovery week. After a race or hard training period.
  • -30 < Form < -10 : Optimal Training Zone.
  • Form < -30 : Over Load Zone. Athlete is on overload or over-training phase. He should take rest!

So in general terms

· Fitness is the slowest to increase (or decrease) over time

· Fatigue goes up and down much faster than fitness over time

· As Fitness goes up, you are able to sustain more fatigue/workload that you could before – and need to keep increasing fatigue/workload over time to keep your fitness increasing

It is a very nice model since it allows you to have a rough view to make sure that you are training the right amount to get fit without getting ill and it also predicts how your fitness/fatigue will respond over time and so provides a rough way to taper for events to make sure that you are ready for an event

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For example after today’s workout my form is -24 and optimal for improving fitness – if I did no training then the model predicts that I would hit the “freshness zone” (and be on top form) on the 6th Feb

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So to summarise – StravaistiX can help you track your fitness, check to make sure you’re working hard enough to increase your fitness and give you an idea how to taper enough to make sure you are fresh for race day. Now although StravaistiX was originaly set up for running/cycling, I believe the general principle should also help apply to rowing as well (physiology is physiology after all) and at the very least it gives you a way to compare workouts and compare the intensities of different types of workouts.

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The 2016 rowingmusings Rowing Tech Xmas list

Well it’s the time of year for a Good wish list, so I thought I’d throw together a short list of some of the better gadgets out there for rowers just in case anyone needed a last minute idea for a present!

STROKEMETER

NK GPS 2, COXMATE GPS, ACTIVETOOLS ACTIVERATE

Three solid choices really, if you have the money/row on a river so current cancellation is important/think you’ll ever consider getting the Empower Oarlock then it’s the NK every time.

If you’re happy with just GPS and want to save a little money and think some of the additional features like course correction is useful then the Coxmate GPS is worth a shot

If you’re just after rate, the active tools activerate gives you excellent build quality and some useful extra features like check to help improve your technique

POWER METER 

NK Empower Oarlock

No brainer this one really – although only just released it’s immediately shot to the top of the list for anyone looking to get into power on a lower budget, the more expensive options like peach innovations/BioRow are still a better option for people to get the most detailed data on their rowing, but for most of us the empower oarlock does enough for our needs of giving accurate feedback on power/length and rowing efficiency 

HEART RATE STRAP

WAHOO Tickr X

Still the best out there imo, the Tickr range as a whole is excellent due to the fact that it broadcasts on both ANT+ (for C2 and Garmin) and Bluetooth (smartphones, NK etc) at the same time but the extra features of the X include an accelerometer so when using the Wahoo app it can track your cycling/running cadence for cross training and can even count the reps you do when you run their body weight circuit app, and internal memory so you can always be able to download the HR data after a workout to the Wahoo app even if there is a problem recording during the workout (got to love backUp data)

GPS SPORTS WATCH

Garmin Vivoactive HR

Personaly recommend the Vivoactive HR, if you can’t quite stretch to buying one the Polar M400 is a good budget alternative however I think the Vivoactive HR’s ability to actually track stroke rate directly is a huge plus that is worth the extra, and if you have the money the Fenix 3 does the same and has a inch more premium look

ROWING CLOTHING
KYMIRA IR sportswear

I have been happily using KYMIRA gear for a while, it’s very very comfortable and warm in the winter but also not overly oppressive in the summer – the price is high for compression type gear but not hugely so than the main named brands and the fact they also provide the IR benefits is a big plus to me

DRONE

Parrot Bebop 2 

As time goes on more and more drones are becoming available at prices that make it easier to think about buying one. Now with my recommendation, although there are more feature complete drones like the DJI Mavic, the parrot bebop 2 is a similarly compact drone which is considerably cheaper than the DJI Mavic and yet still provides excellent stabilised videos, offers features like follow me/waypoint flying etc with smartphone apps and has a battery life of 20+ minutes. I have the skycontroller which means it can fly for several km but if you are wanting to carry less bulk then the drone works well with just a smartphone to control it  
Id welcome anyone else’s thoughts or recommendations?

Posted in Uncategorized | 4 Comments

NK Empower gate starts to ship

Buff said really, NK have started to ship their gates out to people who have already pre-ordered 

As I’m in the U.K. I’m hoping there will be an announcement of availability over here soon, plus announcements from data management companies (Rowe.rs for example) how users can start using the power data in training since a major part of using power data is the analysis between rowing 

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