Efficiency...The New Thing?

jsirabella said:

Hello All,

1) I went to Dallas this weekend for a convention and picked up a bicycling magazine for the ride and read about the article about efficiency and how it is the hot thing. The Polar CS600 does it besides watts and hrm. I like numbers because it is easy for me to follow. Is there anything to this new way of gauging how good you are and will it replace watts?

Real or just another way to waste your money on a new toy?

-js

2)I saw a couple posts of why people started training and saw your thoughs about entering crits KO. Family comes first!
I feel if I can make these watts happen or win a race than I can do other things. I find that the only way I can stick with something is if the reason keeps changing.

3)I see too many guys in the gym lifting weights and they look the same, lifting the same as they did years ago...makes no sense to me. So I guess vanity would be last...big ego boost for a 42 years old with gray hair when a girl comes up and asks me if I do triatholon or a quick smile when I get off the erg/spinner. I seem to get that more now...which is alot higher than never as it was before.

1) Personally, I think that Polar is too far invested in HRM to seriously just back step and admit that power is really the key figure. To me, their efficeincy guage smacks of gadgetry. But, I also think that is where the "rides lots" crowd does get advantage. I would think that efficency does have a strong correlation with hours on the bike, limited only by the caveat that lots of practicing in bad form perfects bad form. I still think that, all things being equal, and they never are equal, the rider with better FTP should outperform a less powerful rider.

2)Time and family are the factors. With four kids, and a 50 plus hour work week, (even allowing for the down time at work where I can screw around on the internet) carving aside much more than 9 hours a week to be on the bike is a tall order. If you are going to race safely in crits, then you do have to do your fair share of close paceline riding (unless you are just naturally a gifted and relaxed rider), and that only adds to the load because you are riding on the group's schedule not your own. And, most of the races are on weekends, which fill up very quickly once you have kids and their activities. I do miss competing but I think that I would have a hard time integrating formal races into my family life, at least until the kids are a bit older and more independent. So I have to find some way to make cycling "competitive" without competing in formal races. Believe me, I grew up with two brothers very close in age, and nothing didn't turn into a death struggle type of competition. Growing up, if I knew how often my older brother beat off, I would have done it three times as much and made it a competition. And literally, I am the crazy uncle that stages the annual pull up challenge at Easter every year. So, It is tough for me to just accept that it can't be all about my desire to "win" something at 42. The power meter has been a perfect solution to making the hours meaningful and competitive. For me, punishing my regular local riding buddies by blasting our regular two and a half hour hilly weekend ride into just under an 1:55 has to be enough.

3) I have the opposite problem. I tend to need to change things frequently and that may or may not be a disadvantage. I have been cycling and lifting regularly for almost 20 years, but in between there was the wrestling coach phase, the martial arts phase, and now I have been getting into all this gymnastics and bodyweight training. As my wife says, most guys go through a mid life crisis and they buy a porche, her husband has been getting circus equipment in the mail, (this was after my rings arrived that are hanging from my basement). And that only adds to the tradeoff. Trying to perfect a planche, muscle up, or front lever does nothing to make me a better cyclist. If you think fishing for compliments from a gym chick is pathetic, you haven't seen anything until you've seen a 42 year old man demonstrating a better way to press into a handstand to the local girls who take gymnastics. My wife and teenaged son nearly died from embarassment. But I can't stomach bad handstand form.

Wonder how they measure it. 😕

frenchyge said:

Wonder how they measure it. 😕

My question exactly, or even more simply, how are they defining efficiency? The term is used in so many different contexts, are they talking caloric efficiency (remember many Polar HRMs have a calorie burned estimator, emphasis estimate) or some type of mechanical efficiency as implied by the Velonews piece talking about drive train losses, etc.

Gotta believe it's estimates layered on estimates. If so it won't replace power as an objective measure of systemic stress and work output. I don't know of any mathematical models that allow you to plug in efficiency and estimate your time for a hill climb or 40 K TT, plenty of models available to do that with power.....

-Dave

daveryanwyoming said:

My question exactly, or even more simply, how are they defining efficiency?

Gotta believe it's estimates layered on estimates.
-Dave

Here is how Bicycling magazine defines efficiency:

"The idea is that once you've honed your VO2 max and figured out how to produce about as many watts as you can at as low of a body weight as you can maintain, the only place to find more improvement is in efficiency, which incorporates your pedaling skill, your body position, your bike itself, your racing smarts, and all those amorphous factors that, until now, really had no way to be measured aside from counting podium wins."

But it looks like there is not a real opportunity for great gains in the area of "efficency." I quote: "(Look for an article in the winter 2007 issues of Bicycling explaining all you need to know about efficiency - which is a depressingly low number, by the way: 24-26% for highly trained, highly skilled cyclists, as low as 20-21 for most of us.) So, even if you train to be more "efficient," and become as efficient as a pro, then you are really looking at only gains of 3 -5%.

Many of us have seen power gains of 25-30% using a structured program and a power meter. Tyson essentially posted gains of almost 200%. So I would imagine that this type of gadget (assuming that it does what it says it does) only becomes helpful after you have really reached your maximum power potential, and I would imagine that you would have to develop a pretty efficient pedal stroke to get to those levels. Suffice it to say that I am very skeptical that a device can measure: "your bike itself, your racing smarts, and all those amorphous factors."

Given the choice between investing in this gimmick, or having a respected coach watch me ride a hard interval for an hour on a trainer and make comments about my efficency, I would think that it is a no-brainer. Even comparing watts v. average speed is probably more helpful in determining "efficiency." As I said, Polar makes great HRM. Having invested in marketing this technology, and confronted with evidence that HR and VO2 max are not the Holy Grail of training markers, particularly compared to a power meter, Polar comes up with this nonsense. So, now my bike will have a GPS, PowerTap, HRM, and an efficency meter. If Polar can convince everyone to train with a breathing tube while you pull a meter on a trailer behind you that takes blood measurements while you are training, then I will know that PT Barnum was right. l

kopride said:

... - which is a depressingly low number, by the way: 24-26% for highly trained, highly skilled cyclists, as low as 20-21 for most of us.) ...

I missed that when I skimmed the article. They're almost certainly talking about metabolic efficiency or the ratio of Calories to kilojoules produced while pedaling. Maybe not, but those numbers are roughly what you'd expect for metabolic efficiency.

Sounds a lot like they're taking their existing method for computing the Calories you should have burned (based on HR and estimates) and comparing it to kilojoules of work actually performed. If so it's backassward, with a PM (including Polar's own PM technology) you have actually kj of work performed, you don't need a less accurate estimate as a reference baseline.

But even if it's based on some more accurate methods it will fall into the camp of interesting metrics. It's not like you'll go out and pace a particular ride, race or interval on efficiency, track your time spent at a certain efficiency or track your efficiency at various time durations to guide your training or plan your racing.

I'm with you kopride, Polar is deeply embedded in HRM technology and looking to spin what they know into the next must have gadget. I'll be very surprised if there's more to this than marketing hype.

-Dave

Hey Dave,

The quote from the article is as follows:

"It doesn't measure--it calucaltes. The $710 polar cs600 with power system monitors your power, heart rate, speed, rate of ascent or descent. altitude and cadence, then crunches those figures against data such as your VO2 max, weight, age, gender and fitness level. The calculations also provide you with engaging features such as real-time left-right pdeal balance, which shows if one leg is producing more power."

It seems to also now the mood you are in, your menstrual cycle, how much drinking you did the night before...just screwing around but I mean come on, it seems to be able to make coffee too. Too much data!! The article makes it sound almost like star trek technology...crazy to me.

But they claim, it is the next big thing for the pros and the numbers are terrible and the pros can do a 23 and they have seen one guy hit 27. They claim Armstrong went from 21 to 23 during his run of wins in the Tour. Everything else I think KO covered.

KO btw, the article is by Bill strickland who always talks about his rides in lehigh...some derby races...have you ever ridden with him. Thought you may have caught him if you were in his area of PA.

-js

daveryanwyoming said:

I missed that when I skimmed the article. They're almost certainly talking about metabolic efficiency or the ratio of Calories to kilojoules produced while pedaling. Maybe not, but those numbers are roughly what you'd expect for metabolic efficiency.

Sounds a lot like they're taking their existing method for computing the Calories you should have burned (based on HR and estimates) and comparing it to kilojoules of work actually performed. If so it's backassward, with a PM (including Polar's own PM technology) you have actually kj of work performed, you don't need a less accurate estimate as a reference baseline.

But even if it's based on some more accurate methods it will fall into the camp of interesting metrics. It's not like you'll go out and pace a particular ride, race or interval on efficiency, track your time spent at a certain efficiency or track your efficiency at various time durations to guide your training or plan your racing.

I'm with you kopride, Polar is deeply embedded in HRM technology and looking to spin what they know into the next must have gadget. I'll be very surprised if there's more to this than marketing hype.

-Dave

daveryanwyoming said:

My question exactly, or even more simply, how are they defining efficiency?

Probably incorrectly. 😉

daveryanwyoming said:

Sounds a lot like they're taking their existing method for computing the Calories you should have burned (based on HR and estimates) and comparing it to kilojoules of work actually performed. If so it's backassward, with a PM (including Polar's own PM technology) you have actually kj of work performed, you don't need a less accurate estimate as a reference baseline.

Not only that, but it essentially entails circular logic: to get from heart rate (and other metrics) to kcal of energy expended requires that you assume a value for efficiency, so variations in their calculated energy expenditure vs. actual work performed basically just tells you that your heart rate was higher or lower than expected based on their formulae.

kopride said:

Here is how Bicycling magazine defines efficiency:

"The idea is that once you've honed your VO2 max and figured out how to produce about as many watts as you can at as low of a body weight as you can maintain, the only place to find more improvement is in efficiency, which incorporates your pedaling skill, your body position, your bike itself, your racing smarts, and all those amorphous factors that, until now, really had no way to be measured aside from counting podium wins."

Leave it to Bicycling to take a simple idea and conflate it with common misconceptions to create even more confusion...

In the present context (i.e., the physiology of exercise) there is but one definition of efficiency, which is the same as in other fields (e.g., engineering, physics):

Efficiency = energy out/energy in x 100%

The "energy out" can only be measured using a power meter (or in a lab on an ergometer), whereas the "energy in" can only be measured using a metabolic cart (or a whole-body direct calorimeter, but those are rare). The most important determinants of cycling efficiency are saddle height (too low is bad, but too high is even worse), cadence (higher is usually not better), and fiber type (more slow twitch fibers = higher efficiency). OTOH, pedaling "skill", how you sit on the bike, your tactical sense, and your bike itelf have little or nothing to do with it.

acoggan said:

Leave it to Bicycling to take a simple idea and conflate it with common misconceptions to create even more confusion...

In the present context (i.e., the physiology of exercise) there is but one definition of efficiency, which is the same as in other fields (e.g., engineering, physics):

Efficiency = energy out/energy in x 100%

The "energy out" can only be measured using a power meter (or in a lab on an ergometer), whereas the "energy in" can only be measured using a metabolic cart (or a whole-body direct calorimeter, but those are rare). The most important determinants of cycling efficiency are saddle height (too low is bad, but too high is even worse), cadence (higher is usually not better), and fiber type (more slow twitch fibers = higher efficiency). OTOH, pedaling "skill", how you sit on the bike, your tactical sense, and your bike itelf have little or nothing to do with it.

Thank you. Maybe a brief lecture on delta efficiency and the slow component of VO2 max is in order...

kopride said:

Here is how Bicycling magazine defines efficiency:

"The idea is that once you've honed your VO2 max and figured out how to produce about as many watts as you can at as low of a body weight as you can maintain, the only place to find more improvement is in efficiency, which incorporates your pedaling skill, your body position, your bike itself, your racing smarts, and all those amorphous factors that, until now, really had no way to be measured aside from counting podium wins."

But it looks like there is not a real opportunity for great gains in the area of "efficency." I quote: "(Look for an article in the winter 2007 issues of Bicycling explaining all you need to know about efficiency - which is a depressingly low number, by the way: 24-26% for highly trained, highly skilled cyclists, as low as 20-21 for most of us.) So, even if you train to be more "efficient," and become as efficient as a pro, then you are really looking at only gains of 3 -5%.

Huh? If your efficiency increases from 21 to 26 percent, efficiency increases almost 24%...

Now, can that really be done? U into Type II - Type I fiber conversion?

jsirabella said:

Hey Dave,

KO btw, the article is by Bill strickland who always talks about his rides in lehigh...some derby races...have you ever ridden with him. Thought you may have caught him if you were in his area of PA.

-js

Rodale press is based in the Lehigh Valley and some of the writers frequent the rides that leave from the Trexlertown Velodrome. A lot of strong riders including Marty Nothstein train there so a lot of these guys are the real deal. And their "A" level group rides have a local reputation for being some of the toughest rides (brutal hills and brutal pace) in the area. I jumped on some group rides there in the distant past, early nineties, but it is a little far for me to make their regular group rides. We have a pretty strong local riding scene in Philly and Chester County that I can barely jump in with so I can't say that I will be riding with Bill or anyone else from there to give him my 2 cents about their product reviews. I must say that when I see Rodale running ads for Twinlabs products and am tangentially aware of some of their litigation over the "old unsolicited product" sales tactics, I am highly skeptical that their advertising budget doesn't affect their product reviews. But there is no doubt that there is more than a fair share of very fast riders who are part of the Lehigh Valley scene, track and road. We are in the middle of the Commerce Bank pro series in SE PA, which will finish in Philly this weekend. And generally, Rodale is a very benevolent sponsor of cylcling locally so I shouldn't be too harsh.

john979 said:

Huh? If your efficiency increases from 21 to 26 percent, efficiency increases almost 24%...

Now, can that really be done? U into Type II - Type I fiber conversion?

How much does your FTP increase with that increase in efficiency?

Squint said:

How much does your FTP increase with that increase in efficiency?

By 24% by the physical definition of efficiency. Say your FTP is 300 watts at 21% efficiency. That means your body is generating 300/0.21 = 1428 watts of energy, of which 300 is useful power output. Increase you efficiency to 26% and your FTP becomes 1428*0.26 = 371 watts, a 24% increase.

My understanding is that increases in efficiency is something that comes from riding your bike a lot, and is extremely sport specific.

acoggan said:

Leave it to Bicycling to take a simple idea and conflate it with common misconceptions to create even more confusion...

The "energy out" can only be measured using a power meter (or in a lab on an ergometer), whereas the "energy in" can only be measured using a metabolic cart (or a whole-body direct calorimeter, but those are rare).

Below find a picture of the metabolic cart you have to tow while using the new Polar Efficiency Meter. It only adds a few grams but the info it provides is well worth it🙂 :
[img]cache.gawker.combike trailer.jpgOpen ↗[/img]

Eldrack said:

By 24% by the physical definition of efficiency. Say your FTP is 300 watts at 21% efficiency. That means your body is generating 300/0.21 = 1428 watts of energy, of which 300 is useful power output. Increase you efficiency to 26% and your FTP becomes 1428*0.26 = 371 watts, a 24% increase.

My understanding is that increases in efficiency is something that comes from riding your bike a lot, and is extremely sport specific.

I am not so sure it has been proven that increases in efficiency come from "riding a lot". The adaptations may be more intensity than duration driven, so it is the right combination of intensity plus duration that increases efficiency. A little bit of thyroid hormone doesn't hurt too....

I doubt anyone ever increased their efficiency by 24% too.

Eldrack said:

By 24% by the physical definition of efficiency. Say your FTP is 300 watts at 21% efficiency. That means your body is generating 300/0.21 = 1428 watts of energy, of which 300 is useful power output. Increase you efficiency to 26% and your FTP becomes 1428*0.26 = 371 watts, a 24% increase.

My understanding is that increases in efficiency is something that comes from riding your bike a lot, and is extremely sport specific.

No, the whole equation is circular. The 24% has nothing to do with watts. Watts is an objectively measured output. "Efficiency," as defined by Polar appears to be some assumed relationship between alleged Kilocalories consumed and heart rate, etc. see Coggan's post above: " to get from heart rate (and other metrics) to kcal of energy expended requires that you assume a value for efficiency, so variations in their calculated energy expenditure vs. actual work performed basically just tells you that your heart rate was higher or lower than expected based on their formulae." This is the issue Power users have made with respect to extrapolating heart rate data. Presumably, a pro has a lower HR than me at at the same speed and is consuming less calories per watt outputed. Assuming that I am heavier, I will consume more Kcals than the pro to output a similar level of power. OK so maybe I have to eat more riding than the pro to bonk.

Eldrack said:

That means your body is generating 300/0.21 = 1428 watts of energy, of which 300 is useful power output.

Careful with your units, Mr. Physics Student. Watts are for power, energy is in Joules. It's a nitpick but I remember losing more than a few points off freshman exams due to stuff like that.

kopride said:

"Efficiency," as defined by Polar appears to be some assumed relationship between alleged Kilocalories consumed and heart rate, etc. see Coggan's post above: " to get from heart rate (and other metrics) to kcal of energy expended requires that you assume a value for efficiency, so variations in their calculated energy expenditure vs. actual work performed basically just tells you that your heart rate was higher or lower than expected based on their formulae." This is the issue Power users have made with respect to extrapolating heart rate data. Presumably, a pro has a lower HR than me at at the same speed and is consuming less calories per watt outputed. Assuming that I am heavier, I will consume more Kcals than the pro to output a similar level of power. OK so maybe I have to eat more riding than the pro to bonk.

There's so many assumptions in there that the whole thing is pretty tenuous.