Left Right Power Analysis

Discussion in 'Power Training' started by Felt_Rider, Nov 6, 2013.

  1. Felt_Rider

    Felt_Rider Active Member

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    One of the reasons I have Alex Simmons as one of my favorites on my blog is how he writes in a way that even a simpleton like myself can understand and yet present some things for us to consider especially concerning the trend is Left/Right power readings as live data and as uploaded data.

    I hope he doesn't mind me posting a link to his blog post, but here it goes
    http://alex-cycle.blogspot.com/2013/11/left-right-out-of-balance.html

    It is good to read the post and consider some of the potential equipment and application issues that currently exist especially if you are one of those that in the camp and theory of "balancing" left/right torque.

    I personally found this whole thing to be interesting as it popped up a few years ago with PM's coming to market like back as far when Metrigear was working on what we now know as Garmin Vector and others like Brim Brothers. But even then some of the other PM's quickly looked into how they could create a left/right output with their current models. Garmin of course worked quickly on firmware updates to show live left/right balance.

    I think for me what is interesting is my view on how to approach balance based on an extensive background in strength training competition, consulting and training others. I would not dare say that my methods of working on strength imbalances is the best approach and there would be multitudes of strength coaches that would be in the opposite camp than me. Most of us that have either competed or trained others it is just a visual observation and there are not a lot of good studies on this subject so there is no way I could state that I have a good understanding.

    However, cycling is a bit different because of the use of power meters and applications allow the person or coach to look beyond visual observation. But as Alex pointed out there needs to be some refinements in order know if the left/right data is accurate, which you can read some of the things he points out for drive train location and other aspects.

    So I am a bit stuck in my own observations as far as working and training in strength for so long that it makes it hard for me to buy into why a person would need to focus in that deeply to such imbalances. As I was looking around the web yesterday and read an academic article from a physical therapist he stated what I find to be true in my observations and that is the body has a keen way of working things out on its own without the need of special attention. This statement was in context of a healthy athlete and not in terms of rehabilitation for injury recovery or other type of disability. Now if there is something wrong like a muscle strain another type of injury where one side is compensating for the other side there is a greater risk for further injury. I had that happen a number of times through the years while lifting where tendonitis or something causing a weakness on one side and the other side compensates to pick up the slack during the lift the risk for serious injury exists.

    As an example of what the physical therapist (medical doctor) said about how the body has a keen way of working out the imbalances is the camp that I was in where if a lifter had an obvious imbalance the approach we took was to do nothing special about it.

    For example one of the more obvious very visual was a new lifter on a flat bench bar press and you will see many experience this as one side comes up and the other side shows that it is lagging behind. I experienced the same thing over 30 years ago when I first started lifting and it was those who were consulting me at the time just said, "don't worry about it. It will work itself out in time."

    The theory was to use a weight that the weaker side can handle for training. The stronger side will not get stronger because it can already handle that load and it is actually too light so it is not really getting the stimulation it needs. The weaker side begins to catch up because it is training and the stronger side is sort of just maintaining. In time, sometimes in just a few weeks, you will see that lifter begin to balance out the bar in the travel path. Or at least it appears to be balanced. However, as Alex stated in his post there are always imbalances. You can observe a world class lifter seemingly look balanced when training up to 90% of their maximum, but if you look at lifts at the Olympics or other high level events you will see even world class lifter be somewhat imbalanced in a 1 rep maximum lift. However, I many do not work specifically on having absolute 100% balanced strength. Of course there are some that fall into the camp that believes the opposite of my camp and I respect that. I know this has an impact on my thoughts for cycling training where left/right data is not that important to me at the moment as I tend to think the body has a keen way of working things out. Maybe someday it will be.

    I will summarize my post as I really don't know what is the best path, but it is kind of neat to see some advancements that I hope sports science can look into these matters for us. Anyway I am grateful to those like Alex and DC Rainmaker for looking into these matters for us so that we as consumers know if the data is something worthy to look at.
     
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  2. Felt_Rider

    Felt_Rider Active Member

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    I just wonder if accuracy was not an issue and one was able to look at true left / right power then what would you do with it?

    Is it just a shiny object of distraction (gimmick) or does it have some use?

    How would one look at the data?
    - Would you look at data over a span of rides to see if one side is typically lagging by a certain percentage?
    - Would you need to look at data in the different levels under a certain training structure to see if there is an imbalance only in certain levels?


    If you were to see an imbalance by what percentage is acceptable before it needs to be addressed?
    If the imbalance is at a certain percentage does that constitute specific rehabilitation and physical therapy?
    If the imbalance is small does it make sense not to get distracted from the overall goals of improving holistically in terms of aerobic and anaerobic fitness? (my point above in train equally and let the weaker side catch up in hours, weeks and years of consistent training and accept that it is near impossible to completely balanced for both sides)

    As this feature is being marketed to the mainstream will it be of any use or will it just be a distraction to the average time constrained cyclist that would do well to remain focused on the holistic goals (using both legs) rather than spending time chasing isolation type training like single leg drills?

    If it is for the purpose of rehab/physical therapy let's hope that we stay healthy and don't need to use that feature.

    Just a few questions that I wonder about regarding this feature.
     
  3. sebo2000

    sebo2000 New Member

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    I thought my vectors are not 100% correct when I saw 48%-52% ration on my rides.

    Then I did test pedaling at 100W with left leg then with right. Only then I realized my left leg is MUCH weaker, average wattage was 20W less and it was much less stable than right leg.

    I still do not know how to improve my left leg cadence, beside pedaling with my left leg, but fact is fact it is weaker.
    Anyone with PowerTap can check this, just pedal with each leg separately for duration of time to get you tired then pedal for another minute. Check your power graph you can compare the wattage and see the difference in strength.
     
  4. Alex Simmons

    Alex Simmons Member

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    Keep in mind that single leg pedalling does not replicate how each leg pedals when using both legs. It's a significantly different action. You need an inertial load, a counterweight, on the opposite pedal to more closely reflect what's going on.
     
  5. sebo2000

    sebo2000 New Member

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    I agree, I was not trying to replicate how both legs pedal. I will go further and agree with you; it is impossible to replicate both legs pedaling, by pedaling single leg.

    I was trying to check the difference when pedaling with right leg only and then left leg.

    If legs would be identical and my body would be perfectly symmetrical, left and right leg pedaling would output exactly the same results. My legs and body is not symmetrical, I can say that by looking at the shoe sole.
    I suspect my handsback etc. are compensating for quite a big difference in legs itself.
     
  6. Felt_Rider

    Felt_Rider Active Member

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    I still wonder though if is it highly critical for performance to strive to have both side equally balanced? Apart from physical rehab from injury/disability.
    Maybe it is once the athlete is near the limit of their genetic potential and are competing at a much higher level. I would think for the lower level cyclists simply working on a holistic approach to improve overall power would still be the primary focus if they are time crunched.

    No doubt it would be really nice for you to gain that extra 20 watts on the weaker legs if that is an accurate number. My thoughts on the earlier post were how will coaches approach this if accuracy is worked out and coaches or athletes can tell the exact imbalance. What will be the approach to balance the weaker side if any?

    Edit: Please note that I am not trying to be negative toward L/R power output. I am mainly curious how coaches will look at this aspect for their clients and hopefully they will take note of some of the current issues of accuracy that Alex stated in his blog post.
     
  7. dkrenik

    dkrenik Member

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    I'm thinking that just because there's little knowledge on how to apply the data collected from L/R analysis now doesn't mean that there won't be something in the future. Who knows, after the coaches and Ex Phys folks get to play around with the data for a while, something(s) pretty interesting may (or may not) come up.
     
  8. Alex Simmons

    Alex Simmons Member

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    Of course, but that something just isn't overly clear at the moment.
     
  9. dkrenik

    dkrenik Member

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    Agreed and exactly the point of my post.
     
  10. sebo2000

    sebo2000 New Member

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    Quote: Originally Posted by Felt_Rider . I still wonder though if is it highly critical for performance to strive to have both side equally balanced? Apart from physical rehab from injury/disability.
    Maybe it is once the athlete is near the limit of their genetic potential and are competing at a much higher level. I would think for the lower level cyclists simply working on a holistic approach to improve overall power would still be the primary focus if they are time crunched.

    No doubt it would be really nice for you to gain that extra 20 watts on the weaker legs if that is an accurate number. My thoughts on the earlier post were how will coaches approach this if accuracy is worked out and coaches or athletes can tell the exact imbalance. What will be the approach to balance the weaker side if any?

    Edit: Please note that I am not trying to be negative toward L/R power output. I am mainly curious how coaches will look at this aspect for their clients and hopefully they will take note of some of the current issues of accuracy that Alex stated in his blog post.


    I could not agree more. Lookinganalyzing at my example. 20W difference between left and right leg when pedaling with single leg, when pedaling with both legs 45-55% @ 204W 91.8W-112.2W – also around 20W difference. Seems like a lot but 20W is really not much, If I would like to improve by 50%(huge number) it would give me 10W advantage. I do not think perfect 50-50% is even possible because we are never perfectly symmetrical.
    The time I would need to dedicate to left leg would need to be subtracted from right leg training, by increasing my left leg I could decrease my right leg wattage. In my case I would do much better by stretching and working on proper position on the bike, to stay more aero, or work on higher cadence or general FTP work. That would be best bang for the buck at 7-8 hours of winter training a week.
    People do not realize there are better more effective methods to be faster. L-R training would be close to other oposite spectrum of things to do, to improve overall power. At 25-35 hours of training a week I could revisit my strategy and go for that extra 10W in my left leg. at 7-8 hours no way.

    I’m also not negative toward L/R I’m just trying to make people realize we need to place training segments and wattage advancements in to proper spectrumperspective.
    It could be done by asking question: How many Hours a week you train, or what is your weekly TSS goal or what is your goal overall?
    Same as paying top $$ for cutting edge equipment and extra 30g less, we will pay extra for training on left leg to gain that top extra 10W. At certain level for certain people it will be 100% worth the effort, for 99.9% of cyclists no way (my stats might be little off, in the sense I over estimated it.)
     
  11. smaryka

    smaryka Member

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    So what's the recommendation if you find one of your legs dominating more than the other in certain situations? Simply make a conscious effort to push the other leg harder?

    E.g., I have some L/R data from rides done with a Power2Max, mostly short hill climbs. One of my climbs was a 10 min effort that could be broken into 3 more or less equal duration sections -- a steep first part, a shallow draggy middle part with some downhill, and another steep part to finish. It turns out that my right leg is quite dominant on the steep parts but the left leg was dominant on the descent and draggy bits. My right leg is a bit shorter than the left, something I compensate for with cleat position though I suppose cleat wedges might be a better solution.

    Here's what the trace looks like. I was seated for the whole thing except the start and finish and once just after halfway to get over a hump between downhill bits. It's interesting to compare the traces of cadence, speed, power and L/R balance though. Never gave L/R balance much thought before but now I wonder... is it worth thinking more about?

    [​IMG]
     
  12. Alex Simmons

    Alex Simmons Member

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    Only if you can reliably identify how such information can lead to an improvement in performance. And therein lies the problem.

    IOW attaining symmetry isn't the objective, improving performance is, and as yet we have nothing to suggest targeting symmetry (let alone how that might be achieved) will naturally lead to an improvement in performance.

    Such ideas may well come with more time and study and there will no doubt be a slew of services based on flimsy premises available in the meantime.
     
  13. sebo2000

    sebo2000 New Member

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    Very interesting. I can see my charts are quite similar.

    When I’m just simply hammering my guts out, just blind stupid power, my right leg participates much more, with ratio 45-55%. On descends or technical riding difference goes down to 48-52%, 49-51% sometimes I’m 50-50%

    I can clearly see “better” balance when I have to “think” when I’m riding. I see the same on rollers, much better balance then on trainer.
    I guess when I “turn on” my right side of brain; my left leg spins much better. As stupid as this might sound that is what I can see in my data files.
     
  14. smaryka

    smaryka Member

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    Yep, but I guess I was thinking that if one leg is putting out more power, than the other could put out more power too? But yes I understand that there's not been much research done here yet so it's hard to say.


    It does make you wonder! Next time I have use of the Power2max I will set up the Garmin to display L/R power and play around a bit with it.
     
  15. go4sporting

    go4sporting New Member

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    that‘s very nice but now our country is very cool,so I dont go4sporting,I think I like pig lol
     
  16. alienator

    alienator Well-Known Member

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    Uhm, this forum is about training with power data. If you're interested in bestiality or spamming your company, you should go elsewhere.
     
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