Left right powermeter data analysis

More and more powermeters nowadays are equipped to measure how power (better said: torque) generated is distributed coming from the left and the right leg. A good example of these meters are the Look Keo Power system and the Garmin Vectors. The Pioneer pedal system even goes further and shows data on different angles of the pedal stroke. What you can actually do with this kind of information – how actionable it is towards increasing performance – is however still questionable. If you read some on this topic you find it mostly in the ‘recovery from injury’ sphere, but you won’t (at least to my knowledge) find any actionable results from scientific literature (let alone the fact that a lot of this literature is often not even actionable).

So why did I want to look at this information? Because I was just interested in it. If you’re interested as well continue to read or otherwise stop here.

Before I show some results of the analysis I will say something about the setup. As you’ve probably already read I ride with a power2max. The analysis I did was based on the ‘normal’ Power2max (not the Type S). This Power2max was updated with left/right balance and temperature compensation a year ago. I use a Garmin Edge 500 head unit and I have Rotor Q rings (52/38). Why do I say this? Because the Q rings might influence the left right readings since power is distributed a bit different than on normal round rings. This does –as seen from some posts- influence power readings and maybe also causes the left right assumption (see below) even more doubtful and influence the results. I am not an engineer, but it would be nice someone could elaborate on that more.

Now, the measurement of the left right balance is done by measuring the stroke across two sections, but essentially it does this by taking the right side. Looking from the right of the bike (where the chainrings are) from 12pm to 6pm (downstroke) for most cyclists most of the power is exerted (right leg) while the left leg basically comes into play on the upstroke (6pm to 12am) . Basically the Power2max makes the assumption that power from this upstroke comes from the left leg. See below a picture (reproduced with permission of Ray Maker / www.dcrainmaker.com).

 

So the way it measures left/right balance is not like a pedal based system. I have tried some left/right drills (as DC rainmaker) and it won’t show 100% left or right power. DC Rainmaker also has done some tests and it came out his rides were dominated by his right leg (47% left / 53% right). Those numbers came from a rather steady (in terms of power) ride.

 

Data used

For the analysis I used a variety of data,

-       1 crit race (40km) with a hill in it (31 aug 2013)

-       1 Les Cingles (3 x Mont Ventoux) ride (4 jul 2013)
-       1 hour FTP test (10 jul 2013)
-       1 Mont Ventoux Climb and another climb (27 jun 2013)
-       1 VO2max 5 min and 20 min FTP (19 feb 2014)
-       2 x 20 min @ FTP (22 feb 2014)
-       A ride with 40min @ FTP (26 Feb 2014)
-       1 hour FTP ride (5 March 2014)
-       5 x 3 min @ VO2max ride (7 March 2014)
-       A 3.50h easy ride (8 March 2014)
-       6 x 3 min @ VO2max ride (14 March 2014)
-       Trainingrace 50km plus extra endurance kms (16 March 2014)
-       4 VO2max intervals of varying length (10, 8 etc mins) (19 March 2014)

I looked at left right balance from 2 dimensions: cadence and power. Why? Because the way in which power is generated by using difference cadence levels might influence the left/right balance. In other words, you might have a different balance for different cadences and for different power levels. Maybe for high power levels a more right balance and for lower powerlevels a more left balance.

 

There is also the dimension time. The idea behind this is that you might change the balance during the ride. For example the longer into the ride the more ‘shift’ to a certain balance or more shifts. I have not done any analysis on this dimension. I focused on the above two parameters as you will see.

First I show you some very simple graphs to tell just some overall relations. In the first graph you see the relation between power and cadence (cadence is binned into cadence ranges).

 

    

In general when cadence goes up, average power goes up. Why is there such a strange spike? Because there are quite some rides at FTP level andit basically shows my preferred cadence. My preferred cadence is around 88-90. After that you see power drop again. Why? Because it contains a mix of higher cadence with lower power and high power (sprinting, etc) with higher cadence. This mix is more ‘favorable’ for the lower power numbers since cadence if (of course) low and power also.

If I relate power output to the power balance I get the graph from below:

 

This graphs looks a lot like a graph which I have once seen on Andy Coggan’s Facebook. The only difference is that his numbers went to 50/50 for higher powernumbers.If you see this graph you can say right leg dominance on the whole spectrum. 

Cadence in relation to the power balance looks like this:

For very low cadence (below 50) show a more ‘evenly’ distribution as well as cadence around my ‘preferred’ or self-selected cadence . After the self-selected cadence the higher the cadence the more dominance to the right balance.

The final graph shows the relation between cadence, power and the power balance.

 

 

At higher cadence with lower power and low cadence with high power there is a shift to the left balance. On the other diagonal this difference is (way) less profound. In the middle of the image the left % goes to on average 49.8% (this is the average of the cadence range 70-90 with corresponding power 250-350).

Conclusion

The overall conclusion of this piece. What to do with it? The honest answer is nothing. Even if the power measurement of left/right was accurate  I still wouldn’t know what to do with it. Basically a lot of questions are unanswered. What is the ‘optimal’ left right balance to produce power? And what is 'optimal'? Maybe the length of my legs make that this is 'optimal', or maybe not. Maybe my position very much influences these numbers and as such it is 'optimal'. Maybe it is 'optimal' for short time durations or for long durations? In a sense I believe these numbers should be investigated in correspondence to the target performance. So when you’re a 1km pursuiter you should focus these analysis on these performances. Obtaining symmetry cannot be the goal of this, but performance is.

I don’t not really see a 50/50 relation. If you have ‘a fluent powerstroke’ these numbers should be 50/50 (that's what I have read from a quote from P2M somewhere). Most of the time relation is skewed to the right leg (meaning more power from the right leg). As said before I am not an engineer, but maybe the way in which power balance is measured AND the Q ring influence these results. Let alone the way lef/right balance is measured, or better said ‘estimated’. A quote from Power2max (Source: www.dcrainmaker.com) “Power2max themselves says there’s little value in it other than from a marketing standpoint (quoted at Eurobike).’’

I do remain curious of others have also done some analysis on the Power2max numbers and come to the same conclusion n. For me it was just a nice to see, but nothing more. When there is not more (real research) on the topic it remains something under the surface and there are more fun things to play with to give better performance results.

Opening race and victory (!)

Today was the opening race. It was a lap of 3.5km. We had to do 50km in total. There were 40 racers who participated. At the start I did not have the chance to be in the first row because everybody was already standing there. So I just put myself against the fence a few meters behind the last of the bunch. From the start on there was quite some activity and there was a small group that tried to make a break. I raced to them but unfortunately the bunch came back. We also weren't working properly together so it did not have a good chance.

 

When the peleton got back I waited a km or so and then I tried myself from the front of the peleton. Here in Holland (and Belgium) they say it's a 'getelefoneerde demarrage'(which means that everybody could see it coming that I was going to attack; it was not an attack by suprise).

 

When I looked back there was 1 guy. When we came to the part in which there were small cobbles (I do not know the right word, but there were a lot of holes in that road anyway) there were 2 others who also joined us. Immediately we started to work together and going at a pace of 42-44 I knew that the peleton had to do their best to come back if they hesitated.

 

The gap became bigger and bigger and I knew quite soon we were going to hold it to the end. In the last round one guy tried several times to jump away but I countered him. Also when we came into the road to the finish one guy tried and again I countered him. I wasn't sure however if I could manage it in the sprint since I countered all attacks. As a 'track'cyclist I then rode 'slowly'to the finish looking my oponents in the eye. In front was not an an ideal place to be because the wind was blowing right in the face. When I felt I could start the sprint I started and went full gas. I got cramps in my calfs and upper legs but I had to push it until the finish line. I felt one guy coming but I held it and won. Below you can see the race (wattage) details of the last 3 minutes.

You can see the powerspikes in which I counter the attacks. Before the final sprint starts (around 890 watt) I did 2 800, 2 (on average) at 700 watt. As you can also see I am not a real sprinter given those 890 watts at the end ;)

Overall great feeling. Of course when making the break it costs quite some energy but at the end I felt that I got better and the others became less good. Maybe they were already starting to spare themselves in the last 15 kms or so, but anyway, it made me grow in the race.

Overall stats:

As for my training last week. I did some FTP work and VO2max (2 times Kurt and 2 times outside). TSS 460 weekly and 6 hours of total training (+ racing time). I am not going to publish it. Tomorrow the results of the left right analysis.

 

 

 

Trainingweek to forget

This was a week to forget. After Wednesday I still had some nice plans but unfortunately (a.o. because of the weather) it turned out bad. On Friday I wanted to go ans ride outside, but it rained. When the rain was drying up I jumped on the Kurt and for some reason I just didn't have it. I tried Sufferfest Blender. A 1.45min workout with SST, FTP and VO2max intervals; a nice mix (blend) of it all and a hard workout. So hard (and also because I didn't have my day) I couldn't do the last 3 4 minute intervals at FTP. They hurt just big time and my HR went skyhigh. Again, it wasn't my day.

 

On Saturday I wanted to do the weekend endurance ride, but I became dripping wet from the rain. After 30km I was home again......with the idea not to ride on Sunday since Saturday evening the wife and me had a party.

 

Fortunately I did have the opportunity to jump on the Kurt and did Blender again. I wanted revenge because I just couldn't deal with the thought I couldn't complete the thing properly. I had my revenge, but, it is a very hard workout. Simple.

 

Next week I have to take a critical look at my training planning. Lately it has been very unstructured and I want to try to get the structure in again. I will give an update on how I did that.

Some (small) intervals

Yesterday had some time to train and decided to do some intervals at end of LT level. Although I did not feel that good (worked to hard for the boss ;) I did have a good feeling after the training. Below a short summary:

 

 

I started with 10 mintes at 330 watt, after that 8 minutes at 320 watts, 7 minutes at 320 watts, and 4 minutes at 330 watts. I have to say it was not a really structured workout (apart from the recovery between the intervals).

 

The ride did have quite some corners in it and I felt I could not get into a proper pace. Tomorrow (if the weather is OK) I want to do a ride with less corners and 4 ten minute intervals @ 330 watts and 5 minutes recovery. Why 4x 10 minutes @ 330 watts (which is at 106% of FTP)? Because I want to build my FTP to (at least) 325/330 watts in a few weeks from now. With my current CTL(54) I am not going to the FTP of 330 watts, but I can make steps with shorter intervals.  I need to be around a CTL of 65 for 330. Next week it's the start of the racing season so from then I will be able to 'train' more on intervals during the races and with some longer rides (Ardennes) coming up the 330 could be there around half/end of April.

 

As said before I am also doing a small analysis on left/right balance, but I find it quite difficult to get some relevant insights from that. Anyway, that's for later (probably next week).

First trainingrace

On the whole this was a good training week. 470 TSS, 7 hours of training. 7 hours? Yes, that's quite a lot for me at the moment. On Monday  did 1 hour 2x20 min @ 310 watt on the Kurt. It went quite well. On Wednesday the 30s on, 30s off (VO2max exercise of which you can also read in some of my previous posts). On Friday I did the 3 min on / 3 min off VO2max (6 times on) which I could not complete at the wattage I wanted a week before, but now I did manage to do 6 @360 watt on average.

 

Today was a trainingrace day. I went on my bike to the race which was in Breda (about 30kms from my place). There I got my number and rode some laps to warm up. I have to say I was kind of nervous since I last week I saw the average kms they rode there (around 43) and that did scare me a little. The lap was however a lap in which you could go really fast in the corners. And the roadconditions were good. On the road to the finish the wind blew full in the face.....O yes, the race was 50km.

 

My goal of today was: get used to riding in the group again, get used to speed, and (secondary) to do some interval work by trying to be in a breakaway.

 

Anyway, I positioned myself at the start at the back (yes, everyone was already standing there....) of the pack (which consisted of 91 riders). When we were allowed to start I went to the front quite rapidly. My steering is still quite OK in large packs even after almost 16 years. End of the day if you are experienced with that you don't loose it. If you still have to learn it, it can be quite a thing however.

 

(ride 2 is the race)

 

 In the beginning there were several small breakaways but more than say 50 meters you never got. I decided to stay calm continuously at around position 30. It felt OK, I had no problems and looked a few times on my powermeter which said 245 watt (lap). Although I knew it was going to be decided at approximately the last 10-15 laps (of 42) at that time I was not at the front where I should have been. 2 guys went away and I put in a lot of effort to get in the front because I did see the 'danger'of it. I went full gas, made a move (57 km/h) to ride to those guys in one effort. I had 2 or 3 guys in my wheel but the last 10/15! meters (wind full in the face) I couldn't manage to make the connection with the two. And the guys in my wheel couldn't put just 1 small effort in it to make the connection....that just sucked.

 

So, we got caught by the peleton and later I tried again with 3 guys. We did ride together but it went just very very fast and we got caught again. I did however stay in the front and finished 12 overall. Not bad, and given the goals I set myself I can be happy about it. Nothing more.

 

What is nice to see is the time spend in certain 'zones':

 

Normally I do not spend any time in the Neuromuscular zone, but with crits like this it typically hits that zone. Also the anaerobic zone is not really a zone which I train. To be even more competitive I should maybe try to do some stuff in these zones.

 

The overall stats of the race: AW 253, NP 287, Average speed 41.5 km/h, 49,5km. The totale ride was 112km and 207 TSS. A good week which did give me some moral to train better again.

Relaxing ride in the sun

180 watt average and 200 normalised for 110km and almost 4 hours on the bike that's what I remember from the Garmin display. And that's all there is too say. The weather was great and I rode a very relaxing ride with my brother and dad. For my dad it was not very relaxing but he hadn't ridden a lot. But he'll improve.

I am currently trying to dive in a bit more on my left right powerdata. I will post on some of that soon. I am also almost finished with reading the book "Racing Weight" so also some on that soon.

Next week will be a week with the three letter word a lot of the time. It starts with an F. 

Mission failed

106%-120% of FTP which is now 328-372w. I tried the "classic" 6x3 minutes on-off. To be honest it did not go that well and I quit after 5 efforts. 

Four efforts went OK (at some I had powerdrop outs for about 10 seconds due to an antenna), but at the fifth I just lost motivation. Strange? Yeah. Maybe. Sometimes it happens. So I quit. Yes, I did feel a loser for not completing the efforts like they should. Let just say this it's an incidence. Tomorrow an endurance ride. Should be good because the weather is nice.

Unplanned FTP one hour

Yesterday I felt really tired. Maybe it was because of work I don't know. Anyway not a good basis for 2 x 20 min SST so i decided to just ride for an hour @ 220 watt and just listen to the music and relax  with a high cadence (on the Kurt).

In the back of my head I had my ride for today (outside) in which I just wanted to ride at 280 watt for an hour (which is around 95% of FTP). 

Since at the beginning of the ride I had no problem riding at or over 300 watts I just made it a ride for an hour for as hard as I could. I ended up doing 312 watt in one hour (NP and 308 watt AP). Not too bad certainly considering I still felt quite good after that hour. I did zero offsets during my ride and virtually no shifts. And if I did see a shift it was in my disadvantage meaning watts could even be slightly higher. Cadence was also quite good on average. But my heart tate data shows weird things in the beginning....and my speedsensor was corrupt (I glued it yesterday on my spoke, but the result was bad as can be seen...)

Conclusion: I am going to put my FTP to 310 watt and adjust my power levels.

Up to 40 mins

Four rides this week again which is OK. On Wednesday I wanted to do 40 min at SST but I ended up doing 40 minutes at FTP (304 watts on average). Actually it was even higher than FTP tested a week earlier in a 20 minute test which was the same amount of watts, but taking 95% of this would actually be less than an FTP of 304. I did a few zero offsets during the ride and they were very stable. The feeling was good again and I felt that I could hang out longer than the 40 minutes, which is also good. In addition I had some times in which I saw the watts going to 330 again without having a really hard time. I did feel a bit 'scary' then so I did make sure to keep in around 300. Heart rate went up slowly again to stabilize at around 170. The total ride was 1.50min at 283 watts.

On Friday I did just an hour ride at around 230 watts on the Kurt with -just to get heart rate up a bit- 3 5 minutes at 280 watts. On Saturday afternoon I did the Billats again (you can see a more extensive review on those in a previous post). They felt good.  No real problems, I love them. It 's just very good focused work.

Today (Sunday) I wanted to do a training race, but with my wife we decided we wanted to go to the Carnaval with the kids, so I just did a 95km endurance ride. It went quite easy also considering I rode on my 'heavy' X-bike and the wind.

 

The total week ended up with almost 7 hours of training and 455 TSS.

 

This week I want to do another good SST/FTP week starting tomorrow with 2x20 mins. The fourth day in a row.....