Testing individual leg strength

[Yonni]

Hi, complete power newbie here.

I've been reading David Millar's autobiography (great read BTW whether you like or loathe him) and he talks about getting almost the same "power curves" from his right and left legs. Would this be from a pro piece of kit in a testing lab or do all power meters based on cranks give individual data for each leg? I've never seen any software or data from a power meter so patronise me all you like. Idon't know how they work. I'm well aware that my right leg is much stronger than my left and wonder if I could find out how much with a power meter and then do specific training to rectify this and monitor the situation?

Thoughts?

 

[An old Guy]

You could ride a bike using only one leg.

But I don't know what benefit it is to have both legs the same strength.

 

[Yonni]

I'm not trying to get both legs exactly equal but in theory the closer matched they are in power the better your core stability and the more overall power you would produce. This would probably be most noticeable on hill climbs where the stress on your core is often higher on the steeper sections. I would also expect time to fatigue to be extended. This is my guess but no one out there seems interested so ho hum, I'll go ask a fitness guru.

 

[An old Guy]

Originally Posted by Yonni .

I'm not trying to get both legs exactly equal but in theory the closer matched they are in power the better your core stability and the more overall power you would produce. This would probably be most noticeable on hill climbs where the stress on your core is often higher on the steeper sections. I would also expect time to fatigue to be extended. This is my guess but no one out there seems interested so ho hum, I'll go ask a fitness guru.

Due to a car accident I seem to have an imbalance in my legs. I never considered that the imbalance was hindering my cycling. But ...

 

[tonyzackery]

You can get this sort of analysis with a Computrainer. I believe the new pedal-based powermeter from Garmin will have individual pedal stroke power metering capabilities.

Suppose you could do some strength tests in a gym isolating one leg from the other to get good idea of which leg is measurably stronger. The seated knee extension machine would be a good place to start...

 

[Ergogenic SN]

Strength in a non-issue. Shouldn't matter much as there is not a large discrepancy neuromuscular facilitation and/or in the delivery and oxygen uptake between both legs.

 

[Not Sure]

this post has been deleted

 

[jollyrogers]

Originally Posted by Yonni .

Would this be from a pro piece of kit in a testing lab or do all power meters based on cranks give individual data for each leg? I've never seen any software or data from a power meter so patronise me all you like. Idon't know how they work. I'm well aware that my right leg is much stronger than my left and wonder if I could find out how much with a power meter and then do specific training to rectify this and monitor the situation?

Thoughts?

None of the commercially available PMs give left-right info. I haven't used a Computrainer, but I seem to remember Dr. Coggan mentioning that the left-right data spin scan shows is an average from that half of the pedal stroke.

To get a full readout through the pedal stroke, you'd need force measuring pedals from an exphys lab.

The Garmin Vector system will not provide this level of data, at least initially. That's due to a limitation in the ANT+ protocol and the type/amount of data that can flow. The pedals do have the ability to provide this data if the transmission format can support it.

 

[tonyzackery]

Originally Posted by jollyrogers .



None of the commercially available PMs give left-right info. I haven't used a Computrainer, but I seem to remember Dr. Coggan mentioning that the left-right data spin scan shows is an average from that half of the pedal stroke.

To get a full readout through the pedal stroke, you'd need force measuring pedals from an exphys lab.

The Garmin Vector system will not provide this level of data, at least initially. That's due to a limitation in the ANT+ protocol and the type/amount of data that can flow. The pedals do have the ability to provide this data if the transmission format can support it.

http://www.dcrainmaker.com/2010/09/analysis-and-discussion-with-garmin-and.html

Not so sure about the accuracy of your comment regarding the ANT+ protocol. Take a read of the attached article. ANT+ is already capable of supporting the right/left power data. Appears the issue currently is with the head units. Imagine new head units will have already received the necessary update to capture the data...

 

[swampy1970]

Originally Posted by jollyrogers .



None of the commercially available PMs give left-right info. I haven't used a Computrainer, but I seem to remember Dr. Coggan mentioning that the left-right data spin scan shows is an average from that half of the pedal stroke.

To get a full readout through the pedal stroke, you'd need force measuring pedals from an exphys lab.

The Garmin Vector system will not provide this level of data, at least initially. That's due to a limitation in the ANT+ protocol and the type/amount of data that can flow. The pedals do have the ability to provide this data if the transmission format can support it.

Metrigear said they were going to be fully ANT+ compatible and do the full display of left/right force measurment.

From metrigear:

Vector Features
•Precise force measurement system implemented into the hole in each pedal spindle
•Impemented in pedal spindles, requiring no modifications to pedal platform
•Independently measures forces in each leg, and reports total power (watts)
•Sensors and electronics are environmentally sealed inside pedal spindle
•Transferable between bikes – swap pedals and attach battery packs to cranks
•Accuracy of +/- 1.5% of actual force on pedals
•System precisely measures cadence, cadence sensor or magnet not required
•Less than 50 grams of total incremental weight (less than 25 grams/pedal)
•Communicates via ANT+ wireless protocol to ANT+ compatible head units
•Includes ANT+ PC dongle for Vector firmware updates/upgrades as available
•External rechargeable battery pack securely mounts on crank, with a charge indicator on the battery pack







They even stuck the ANT+ graphic on the battery pack. How pretty.

That said, Garmin bought it - so it'll probably be sold as a force measuring device for the bottom of hiking shoes and integrated into an ANT+ wrist watch or in their Sat Nav gear with the sensor detecting hours of force on the car seat before it eventually ends up on a bike...

 

[tonyzackery]

LOL! I hear an echo, echo, echo...

 

[swampy1970]

LOL! I hear an echo, echo, echo...

The only reason that you hear an echo is because you have an empty head... Just like playing a loud amp in a big empty room, reverberation can be a *****. Even with 20kbits/sec and a broadcast mode that doesn't require an ack packet to be sent back there shouldn't been too much in the way of limitations if two ANT+ channels were used. The 'restriction' would likely be in the headunit.

 

[tonyzackery]

^^^All too easy to make the village idiot sit and beg.
Since when can anyone "play an amp"????
LOL! Thanks for the laugh - again...

 

[jollyrogers]

Tony, the below quote from the article is what I was trying to convey. The Garmin pedal system can give you L/R balance, but not where power is throughout the stroke i.e. the Frank Day/Noel Crowley dream (or dream crushing) data

Similarly, the ANT+ spec will still need to be updated to include additional data types such as angle of pedal – which is something that they plan to propose to Dynastream for inclusion with ANT+. But it’s not just MetriGear that wants/needs this, but also the other three ANT+ based pedal manufacturers today working on product (Brim Brothers, O-Synce, Elite…and Garmin/MetriGear).

Quote:
Originally Posted by tonyzackery .




http://www.dcrainmaker.com/2010/09/analysis-and-discussion-with-garmin-and.html

Not so sure about the accuracy of your comment regarding the ANT+ protocol. Take a read of the attached article. ANT+ is already capable of supporting the right/left power data. Appears the issue currently is with the head units. Imagine new head units will have already received the necessary update to capture the data...

 

[tonyzackery]

^^^ No sweat. I believe the OPs concern has been addressed to their satisfaction.
Hopefully, Garmin will get off the fence with this product and get it out to market sooner than later...

 

[danieleaq]

I was also curious to know the drag force of the left leg and right to know that their difference.

To do this I did the test indoors (important because the conditions are always the same) on my Cyclops Indoor Cycles PT300.

A minute with the left leg, right leg a minute. This test has given me important information.

I improved with the use of a horizontal press at the gym, strength in the weaker leg, and of course I have improved the general force pushing on the pedals.

I then noticed a marked improvement in the power tests (20 min)

I hope this helps
Daniele

 

[Alex Simmons]

I have a pretty decent leg imbalance, having had a lower leg amputation 4 years ago.

I've managed to equal or better my pre-amputation W/kg numbers for all durations longer than 4-minutes.

I'd say L-R "balance" is not as big an issue as some might think.

 

[swampy1970]

Originally Posted by danieleaq .

I was also curious to know the drag force of the left leg and right to know that their difference.

I hope this helps
Daniele

Drag force? What's that? Is it a bunch of guy running around in women's undies pretending to be ninjas?

Confused
Swampy.

 

[danieleaq]

Maybe I wrote inaccurate things. I ask for help to translate Mr. GOOGLE TRANSLATE
I apologize for the error.

I wanted to say:
I was curious to know the difference between the left and right legs (strength)

Daniele - Italy

 

[Felt_Rider]

Originally Posted by Alex Simmons .

I have a pretty decent leg imbalance, having had a lower leg amputation 4 years ago.

I've managed to equal or better my pre-amputation W/kg numbers for all durations longer than 4-minutes.

I'd say L-R "balance" is not as big an issue as some might think.

Thanks for the post from a cycling point of view. It seemed like this would be the case.

Training people in the world of lifting many of us that are or have been consultants/trainers hold the same point of view. We often see it really stand out when someone is in their first few months of lifting, such as, bench press and you see the bar go through the range of motion very irregular. Most of the time someone new to lifting believes they must do something special to correct this imbalance, but many of us just have them use a weight that the weaker body part can handle. In time strength will improve in the weaker area without any special focus. After a few months we typically see a balanced range of motion or at least from a visual point of view. (an imbalance is probably still there as it is for many of us, but cannot be seen when using a submaximal stress load)

I was talking to one of my friends that is a doctor and has been a trainer at a high level for a while. We both seem to agree that at submaximal loads it is not an important issue and even at maximal loads like a powerlifter at competition is still not a great issue. We do see at times a world class lifter using maximal weight at competition an imbalance may be visually noticed, but again no one seems to care. It is not something that lifter needs to address specifically.

Then I asked my friend what he thought about cycling and imbalance (he knows nothing of cycling training) but he did say that his thought is cycling is about submaximal work in general and could not see how working on an imbalance specifically would be necessary. I agree.

Anyway I thought this was interesting topic. Thanks for posting your opinion and especially with your condition would have even more insight of imbalance with major injuries and returning physical therapy.