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Are you purposely ignoring my assertion that at a certain size of human you have passed being just naturally larger and are crossing into "too out of shape to do it" territory?
I ride metric centuries all the time and I am in the morbidly obese range. It's just a matter of training. For sure it would be easier if I lost weight, but it is possible to ride well as a fatty.
You misunderstood - I didn't say you couldn't ride well, but putting out the power numbers we are talking about are a bit out of reach for most people even if larger people are capable of putting out more power than smaller people. The argument here is one of degree. Someone is asserting it is possible to burn 1000kcal/hr and we are trying to use raw numbers to say why that is not probably for a typical person. Or even a very fit person.
Actually, you are making assumptions about efficiency that don't match physiological research.0 -
EvgeniZyntx wrote: »Are you purposely ignoring my assertion that at a certain size of human you have passed being just naturally larger and are crossing into "too out of shape to do it" territory?
I ride metric centuries all the time and I am in the morbidly obese range. It's just a matter of training. For sure it would be easier if I lost weight, but it is possible to ride well as a fatty.
You misunderstood - I didn't say you couldn't ride well, but putting out the power numbers we are talking about are a bit out of reach for most people even if larger people are capable of putting out more power than smaller people. The argument here is one of degree. Someone is asserting it is possible to burn 1000kcal/hr and we are trying to use raw numbers to say why that is not probably for a typical person. Or even a very fit person.
Actually, you are making assumptions about efficiency that don't match physiological research.
You are making assumptions that the differences are significant enough to nullify my point, which they are not.
I am done here.0 -
EvgeniZyntx wrote: »Are you purposely ignoring my assertion that at a certain size of human you have passed being just naturally larger and are crossing into "too out of shape to do it" territory?
I ride metric centuries all the time and I am in the morbidly obese range. It's just a matter of training. For sure it would be easier if I lost weight, but it is possible to ride well as a fatty.
You misunderstood - I didn't say you couldn't ride well, but putting out the power numbers we are talking about are a bit out of reach for most people even if larger people are capable of putting out more power than smaller people. The argument here is one of degree. Someone is asserting it is possible to burn 1000kcal/hr and we are trying to use raw numbers to say why that is not probably for a typical person. Or even a very fit person.
Actually, you are making assumptions about efficiency that don't match physiological research.
You are making assumptions that the differences are significant enough to nullify my point, which they are not.
I am done here.
I'm not making that assumption, I actually brought the research (which you've ignored so far) that shows that the starting efficiencies that were made for power to cals are wrong. As are your assumptions that a person weighing 250 lbs can't be fit enough to ride hard for 3-4hrs.
Clearly small changes in efficiency lead to important differences in Metabolic Output.
It's a shame because this was an interesting convo, and brought me back to reading some side papers about VO2max calculations and metabolic efficiency studies.
Bye.0 -
Strength vs Power is matter of duration. Strength is measurement of instantaneous force exerted whereas power is the force exerted over a duration of time. As the time component shrinks, the two meets. Skeletal muscle fiber type contribution of work is also different where strength is derived predominately from Type II (fast twitching) and cycling power is predominately from Type I (slow twitching, and for elites the conversion of Type IIa for aerobic efficiency). Predominately here as there are time where strength is called for in cycling such as rapid acceleration from a standing start or a sprint. That why the mean maximal power for 1-30 seconds is so much higher than say 8-10 minutes (VO2Max) and longer. See http://www.livestrong.com/article/115549-define-strength-power-muscular-endurance/ for a more eloquent definition.
20%-25% is the exercise efficiency not net efficiency that adds Caloric expenditures to keep you alive and such. Please re-read the studies cited and compare apples to apples not oranges. A power meter measures the work done propelling you on the bike and does not include what's needed to keep you alive. Let's agree we are talking about that wattage, else it's pointless.0 -
I ride bicycles. I don't really GAF about numbers. You guys seem like a lot of fun, though.0
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EvgeniZyntx wrote: »
3 w/kg is near the top of cat 5 in Coggan's chart. That's not even close to novice or untrained. Also that chart was built based on his data from about 200 cyclists, weekend warriors to elite level. It would be a mistake to think that the same general rules hold for obese people, since additional fat mass is unlikely to contribute to addition power output. Also, the purpose of the chart is determining the cyclist's phenotype; not estimating power based on kg and not even figuring out what cat you should race in based on power.
So is your only point in this thread that it's theoretically possible that there may be an individual or two on our planet who is 130kg and lean and has off the charts low metabolic efficiency, and could possibly burn 4000 calories in 4 hours? Maybe, but I'm still going to tell an average person who makes that claim he's full of *kitten* unless he's a highly trained cyclist.
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EvgeniZyntx wrote: »
3 w/kg is near the top of cat 5 in Coggan's chart. That's not even close to novice or untrained. Also that chart was built based on his data from about 200 cyclists, weekend warriors to elite level. It would be a mistake to think that the same general rules hold for obese people, since additional fat mass is unlikely to contribute to addition power output. Also, the purpose of the chart is determining the cyclist's phenotype; not estimating power based on kg and not even figuring out what cat you should race in based on power.
So is your only point in this thread that it's theoretically possible that there may be an individual or two on our planet who is 130kg and lean and has off the charts low metabolic efficiency, and could possibly burn 4000 calories in 4 hours? Maybe, but I'm still going to tell an average person who makes that claim he's full of *kitten* unless he's a highly trained cyclist.
This man... he bringeth the truth...
(I know I said I was out but I can't help looking at dumpster fires)
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EvgeniZyntx wrote: »
3 w/kg is near the top of cat 5 in Coggan's chart. That's not even close to novice or untrained. Also that chart was built based on his data from about 200 cyclists, weekend warriors to elite level. It would be a mistake to think that the same general rules hold for obese people, since additional fat mass is unlikely to contribute to addition power output. Also, the purpose of the chart is determining the cyclist's phenotype; not estimating power based on kg and not even figuring out what cat you should race in based on power.
So is your only point in this thread that it's theoretically possible that there may be an individual or two on our planet who is 130kg and lean and has off the charts low metabolic efficiency, and could possibly burn 4000 calories in 4 hours? Maybe, but I'm still going to tell an average person who makes that claim he's full of *kitten* unless he's a highly trained cyclist.
But we are talking about 2w/kg not 3...
if efficiency is somewhere between 18-20% we are looking at 1000 cal burns.0 -
Yes. Not sure why you bring that up.Strength vs Power is matter of duration. Strength is measurement of instantaneous force exerted whereas power is the force exerted over a duration of time. As the time component shrinks, the two meets. Skeletal muscle fiber type contribution of work is also different where strength is derived predominately from Type II (fast twitching) and cycling power is predominately from Type I (slow twitching, and for elites the conversion of Type IIa for aerobic efficiency). Predominately here as there are time where strength is called for in cycling such as rapid acceleration from a standing start or a sprint. That why the mean maximal power for 1-30 seconds is so much higher than say 8-10 minutes (VO2Max) and longer. See http://www.livestrong.com/article/115549-define-strength-power-muscular-endurance/ for a more eloquent definition.20%-25% is the exercise efficiency not net efficiency that adds Caloric expenditures to keep you alive and such. Please re-read the studies cited and compare apples to apples not oranges. A power meter measures the work done propelling you on the bike and does not include what's needed to keep you alive. Let's agree we are talking about that wattage, else it's pointless.
A power meter measures the external work done. Agreed.
Conversion of the power measured gives you:
Gross Efficiency = External Work / Total Energy Expenditure *100
Net Efficiency would be N.E. = External Work / (TEE - Metabolic Expenditure at Rest) *100
I think we are talking about the same thing? If not, please feel free to correct/clarify.
It seems, from that article and others that a) gross efficiency varies with power and b) is sub 20% in heavier individuals.
Anyway, the metabolic base burn is going to be about 100 to 120 cals. I'm not sure if the poster claiming was including that or not.
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Strength vs Power discussion is for robertw486. I'll remember to quote from now on.
No agreeing on the fitness level but that relative. My FTP is derived from 20 minute test (guilty of the seven sins) and like I said there is no illusion that I can hold that wattage for one hour according to it's definition (capable verse probable). It helps set my training zones so that one day I may achieve that.EvgeniZyntx wrote: »Again. At 165 lbs you are a relatively efficient cyclist.
So why throw in the 10% when it's not even in play. Sounds like a red herring.EvgeniZyntx wrote: »I know that the calculations upstream were based on human efficiency of 20-25%. I believe you used 20%. In reality, for the large rider I'm pretty sure we are approaching a lower efficiency. At 10% efficiency (ref: http://d3epuodzu3wuis.cloudfront.net/R061.pdf) the calorie burn of the heavier cyclist will burn more calories at lower watt ranges.
Furthermore, but minor, it's likely that a person stating that they burn xxx during the time of exercise is talking about gross effort and not net. Remember that they already have a head start at 100-130 cals / hr vs 70-80 cals / hr for the lighter person.
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Strength vs Power discussion is for robertw486. I'll remember to quote from now on.
No agreeing on the fitness level but that relative. My FTP is derived from 20 minute test (guilty of the seven sins) and like I said there is no illusion that I can hold that wattage for one hour according to it's definition (capable verse probable). It helps set my training zones so that one day I may achieve that.EvgeniZyntx wrote: »Again. At 165 lbs you are a relatively efficient cyclist.
So why throw in the 10% when it's not even in play. Sounds like a red herring.EvgeniZyntx wrote: »I know that the calculations upstream were based on human efficiency of 20-25%. I believe you used 20%. In reality, for the large rider I'm pretty sure we are approaching a lower efficiency. At 10% efficiency (ref: http://d3epuodzu3wuis.cloudfront.net/R061.pdf) the calorie burn of the heavier cyclist will burn more calories at lower watt ranges.
Furthermore, but minor, it's likely that a person stating that they burn xxx during the time of exercise is talking about gross effort and not net. Remember that they already have a head start at 100-130 cals / hr vs 70-80 cals / hr for the lighter person.
No red herring intended. Plunk in 15% or 18% in that sentence, still holds.0 -
Just a quick question for the cyclers....any tool to gauge a burn on a stationery which gives me distance and watts. I futz(extremely technical term with one minute higher resistance, one minute lower, a couple of sets, then grdual increases on 30 off 30, more sets, and then cool down...saddle time varies, but nowhere near 4 hours) Anybody have something for an approximation I'd be grateful. I use MFP but mostly to have friends flip at the burn. We all know the real burn is closer to 4 calories, not 600+. Thanks in advance.0
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_Terrapin_ wrote: »Just a quick question for the cyclers....any tool to gauge a burn on a stationery which gives me distance and watts. I futz(extremely technical term with one minute higher resistance, one minute lower, a couple of sets, then grdual increases on 30 off 30, more sets, and then cool down...saddle time varies, but nowhere near 4 hours) Anybody have something for an approximation I'd be grateful. I use MFP but mostly to have friends flip at the burn. We all know the real burn is closer to 4 calories, not 600+. Thanks in advance.
I use 100 cal for every 5 kilometres.
Given that I cycle just shy of 20 km/h outside, that works out to just shy of 400 cal/hour.
On MFP I use their Bicycling 16-19 km/h choice, and IIRC MFP gives me about 385 cal for an hour's cycling ... which is right in the ballpark of "just shy of 400 cal/hour".
Therefore, if I ride my bicycle on my trainer for 30 min, that's probably somewhere in the neighbourhood of ... maybe 190 cal?
That's probably not a perfect calculation, but it seems to work all right for me.
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_Terrapin_ wrote: »Just a quick question for the cyclers....any tool to gauge a burn on a stationery which gives me distance and watts. I futz(extremely technical term with one minute higher resistance, one minute lower, a couple of sets, then grdual increases on 30 off 30, more sets, and then cool down...saddle time varies, but nowhere near 4 hours) Anybody have something for an approximation I'd be grateful. I use MFP but mostly to have friends flip at the burn. We all know the real burn is closer to 4 calories, not 600+. Thanks in advance.
Maybe for distance if you can fit a sensor on it to record the number of rotation and calculate it base on the wheel diameter. For wattage, it's going to be expensive if the manufacturer does not have a published curve. You need to establish a relationship between the resistance of the unit to rotational speed of the wheel or retrofit the cranks and add a power meter/use pedal based power meter. And don't forget a head unit that can records the activity at regular time steps. The first is virtual and not really that great in estimating instantaneous power. Your 30 seconds on will be way off. (Assuming the resistance provided is progressive.)0 -
Strength vs Power is matter of duration. Strength is measurement of instantaneous force exerted whereas power is the force exerted over a duration of time. As the time component shrinks, the two meets. Skeletal muscle fiber type contribution of work is also different where strength is derived predominately from Type II (fast twitching) and cycling power is predominately from Type I (slow twitching, and for elites the conversion of Type IIa for aerobic efficiency). Predominately here as there are time where strength is called for in cycling such as rapid acceleration from a standing start or a sprint. That why the mean maximal power for 1-30 seconds is so much higher than say 8-10 minutes (VO2Max) and longer. See http://www.livestrong.com/article/115549-define-strength-power-muscular-endurance/ for a more eloquent definition.
20%-25% is the exercise efficiency not net efficiency that adds Caloric expenditures to keep you alive and such. Please re-read the studies cited and compare apples to apples not oranges. A power meter measures the work done propelling you on the bike and does not include what's needed to keep you alive. Let's agree we are talking about that wattage, else it's pointless.
We're on the same page for strength vs power, but I still see it as needing only power. The cadence and overall torque exerted aren't nearly as important as the combined measure of power. Riders of different builds will ride at different cadences often, to suit what works for them and their build. Though torque influences power, power can continue to rise as torque drops. Everything I've seen indicates that humans have fairly flat torque curves, so really the power part of the equation is more based on leg mass and how quick you can make it change direction in an efficient manner.
As for the efficiency points, I've never stated I was speaking in terms of net power, nor did the OP that I saw. That is why my points were made on rider size having impact on calorie burn rates. Early on I commented on your below statement....
When comparing, watts by itself is kind of meaningless in cycling. It needs to be normalized in order to have significance. Dividing by weight, w/kg, is the true measure used.
Hope this helps.
... which I agree with. Power alone is a meaningless measure. For performance or gross calorie burns, it has to be taken into context with rider weight.
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_Terrapin_ wrote: »Just a quick question for the cyclers....any tool to gauge a burn on a stationery which gives me distance and watts. I futz(extremely technical term with one minute higher resistance, one minute lower, a couple of sets, then grdual increases on 30 off 30, more sets, and then cool down...saddle time varies, but nowhere near 4 hours) Anybody have something for an approximation I'd be grateful. I use MFP but mostly to have friends flip at the burn. We all know the real burn is closer to 4 calories, not 600+. Thanks in advance.
Maybe for distance if you can fit a sensor on it to record the number of rotation and calculate it base on the wheel diameter. For wattage, it's going to be expensive if the manufacturer does not have a published curve. You need to establish a relationship between the resistance of the unit to rotational speed of the wheel or retrofit the cranks and add a power meter/use pedal based power meter. And don't forget a head unit that can records the activity at regular time steps. The first is virtual and not really that great in estimating instantaneous power. Your 30 seconds on will be way off. (Assuming the resistance provided is progressive.)
For a classic solution, pretty much what kcjchang wrote and expensive.
You might want to look into a PowerCal (I haven't used one), which is cheaper and intended as a HR strap + speed sensor that gives power. I'm not 100% convinced but it is reviewed by DCRainmaker.
http://www.dcrainmaker.com/2012/11/cycleops-powercal-in-depth-review.html0 -
And I forgot...
Another possibility is TrainerRoad - a subscription based service with virtual power tool based on trainer power curves.
http://www.alananna.co.uk/blog/2013/trainerroad-trainerrelay-and-workout-builder/
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_Terrapin_ wrote: »Just a quick question for the cyclers....any tool to gauge a burn on a stationery which gives me distance and watts. I futz(extremely technical term with one minute higher resistance, one minute lower, a couple of sets, then grdual increases on 30 off 30, more sets, and then cool down...saddle time varies, but nowhere near 4 hours) Anybody have something for an approximation I'd be grateful. I use MFP but mostly to have friends flip at the burn. We all know the real burn is closer to 4 calories, not 600+. Thanks in advance.
The formula to estimate calories burned, based on 25% gross efficiency is:
Average Watts x Duration in Seconds / 1000
The problem is that gym stationary bikes generally don't have calibrated power meters, so the measured watts can be questionable. If I were you, I'd start with 80% of the formula above and then adjust it if you're losing weight faster or slower than you should be, feel way too hungry all the time, etc.
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EvgeniZyntx wrote: »You might want to look into a PowerCal (I haven't used one), which is cheaper and intended as a HR strap + speed sensor that gives power. I'm not 100% convinced but it is reviewed by DCRainmaker.
The only sticker would be the calibration and OP's workout. If OP's 30s on/off are not in the upper anaerobic capacity range, HR would even out and give him a blended wattage. This could be as close or no cigar depending on the intensity. It will never work if OP is doing true HIIT, in the range of 170% of VO2Max, or there about. There is an interesting post on wattage group regarding a use case for iBike and PowerCal, https://groups.google.com/forum/?hl=en#!topic/wattage/2z2_Rx89M0g. Quoted below since I presume not many here are wattage group members.There are many power-based training experts on this board who hold accuracy and precision as no-compromise, die-on-this-hill requirements. I realize that stirring the pot on Wattage is unnecessary because it is a self-stirring pot, but I'd like to toss out a little food for thought.
My entree to training and racing with power was the iBike. I had been trying to train by HR and found it intensely dissatisfying. It was like pressing on the gas in a car, feeling the acceleration, but the speedometer is creeping up slowly, slowly, sloooooowly. When I saw the iBike on sale at Performance Bike for $250 in the fall of 2007, I snatched one up and started doing power based intervals. I've told my story here on Wattage before -- training with the iBike DRAMATICALLY improved my fitness, my enjoyment of cycling, and my race results. Far and away the best $250 I ever spent on cycling equipment! Many Wattage members disparage the iBike, but it worked for me.
A couple years later, I had been fantasizing about an SRM (there was no Stages or Quarq and I didn't want to be constrained to one wheel set with a PowerTap), so started trolling eBay, found an SRM with a Cannondale SuperSix attached to it, and bought it. The iBike was relegated to my TT bike. TT is a pretty strong use case for an iBike -- same body position, same speed suit, no weight variation due to water bottles or other stuff, etc. When everything is the same as your profile on an iBike, it is quite accurate. I tested and tuned mine against a PowerTap and it was very close before tuning and extremely close after tuning.
The iBike served on my TT bike until I purchased a 2nd SRM power unit for my new CX bike and it had the same BB as the TT bike, so I then shared the SRM between my CX bike and TT bike. The iBike hit Craigslist and was gone.
Recently, for reasons that make great sense to me but seem to baffle my wife, I purchased a set of Powertap P1 pedals.
I also purchased a PowerCal.
That likely caused a great disturbance in the World of Wattage . . . iBike, SRM, 2nd SRM, P1 pedals, PowerCal????
Yes, a PowerCal. I got a new fat bike and wanted to track TSS in order to maintain a reasonably accurate CTL and ATL through the winter months. There is no SRM or Quarq or Stages or any other respected power meter that will fit the crank. And there's no PowerTap hub for a fattie. And I probably wouldn't spend the $$$ for the fattie since most of my rides are moderate intensity for 1-2 hours. But the PowerCal was less than $99 and would not be affected by riding in snow, ice, slush, and whatever else. Precision and accuracy are highly desirable, but I decided a PowerCal would be "close enough".
I must say the Powercal was almost worthless at first -- it was clearly low just based on RPE, so I tested it on the CX bike with SRM and found the PowerCal was always 20-30% low and extremely reluctant to show power above 350w no matter what I did. But I followed the PowerTap calibration protocol as posted on DC Rainmaker's test of the PowerCal (riding a set interval session with both PowerCal and SRM, comparing files afterwards, adjusting parameters to match the power files), tweaked it 2 or 3 more times, and it has now been fairly close on watts throughout my rides and shockingly close on TSS (within a couple of points) based on comparing to the SRM. So there you have it - a use case for the PowerCal! It works well for a bike you're not willing to spend a lot of $$$ on and there's no real solution anyway.
Which brings me to the term "gold standard". Ray Maker and others have said "there's no such thing". Ray admits he has never tested or owned one. My guess is that most or all of the others who don't believe in a "gold standard" don't have much experience with an SRM. Mine work every time I get on the bike. Every time. I don't even think about it, wonder about it, worry about it. They just work every time. Mine have been working every time for 6 or 7 years. I pay $150 to replace batteries every 2 years or so. Other than that, they just work. I love that in a power meter.
The iBike's limitations are well known - a change in weight or tires or clothes will affect the CRR and CDA some unknown amount. While tuning my iBike, I borrowed a friend's PowerTap wheel and it was extremely reluctant to pair with his (not mine!) Garmin once on my bike. No idea why - same wheel, same sensors, same Garmin, many attempts required to pair each time I tried to go for a ride. And another friend of mine has Garmin Vectors which are very unreliable, sometimes they don't turn on, sometimes they don't pair, sometimes they don't produce reasonable numbers. My PowerTap P1 pedals are great once I get a zero offset that is accurate. I always do a zero offset about 10 minutes into the ride, but sometimes, based on years of training with power, I can tell the P1 pedals are not accurate. So I stop and re-zero them until they finally produce reasonable values. If my first experience with power was with P1 pedals, I'd probably be at a loss as to why some days I produced amazing power and other days my power was way down. But, based on my experience, I realize the issue is the zero offset and do it again.
In my experience and opinion, SRM is absolutely the "gold standard".
But I bought P1 pedals instead of another SRM due to the $$$ difference and the portability. Mostly the $$$. If SRM would reduce their price, I'd be even more solidly in their camp. As it is, I have one foot out because it was approx $2K for an SRM and $1K for P1 pedals. And I can use the P1 pedals if I rent a bike while traveling. They can go on the fattie on days without a lot of snow/slush. I wouldn't really want to torture them in winter trail slop, but may keep using the fattie in the spring even in dry weather.
Accuracy and precision are important. But there are use cases for less accurate/precise devices, particularly for those new to power training. I it made me smile inwardly to stir the pot by advocating for the PowerCal in one particular use case!0 -
For stationary bikes and such, I'd dig to see if there are any other outputs that might give a better indication of calorie burn. Some can calculate averages in watts, METs, etc. I'm not sure if any of the stationary bikes calculate miles based on input from resistance or not, but I know our elliptical does. The miles readout is based on their calculation for miles equivalent work, not actual strides vs ramp rate (stride distance is impacted).
I'm really not a fan of anything that uses HR only. With HR data right in front of me all the time on the elliptical, I've seen too many variations that could mess with the numbers for calorie burn. Though intervals at some levels might average out, training variances (and coffee!) can also jack with the numbers. I often do longer stuff at a set point of calories per minute goal, since that is the most accurate metric that my machine displays. But on some days the HR rise to fully warmed up takes a lot longer, and more drift takes place over time as well.0
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