I know, this is a lame excuse for a bike workout but I cannot get motivated to ride the trainer at home late at night. So to the gym I go at lunch.
You folks are super smart so I was curious if anyone has a formula to calculate the wattage on a Platinum Series Upright LifeCycle bike if the Level and RPM are known?
Let the pink comments commence!
Roughly the calories/hr divided by 4.
I had never biked since my $75 third-hand MTB that I used for commuting to work down Magazine Street in New Orleans got stolen eight years before.
Bought a used Jamis hybrid from the LBS to cruise around town with the wife. Thing weighs @28#.
At the gym, rode the Lifecycle before my first ever sprint tri. MPH had me at 23.3 for a good hour or so. I will CRUSH the competition.
At the race, I rode the hybrid and got passed by multiple 13-year-olds and obese people
Bet I could hit 34.5 MPH on a Lifecycle now . . .
I had never biked since my $75 third-hand MTB that I used for commuting to work down Magazine Street in New Orleans got stolen eight years before.
Bought a used Jamis hybrid from the LBS to cruise around town with the wife. Thing weighs @28#.
At the gym, rode the Lifecycle before my first ever sprint tri. MPH had me at 23.3 for a good hour or so. I will CRUSH the competition.
*At the race, I rode the hybrid and got passed by multiple 13-year-olds and obese people *
Bet I could hit 34.5 MPH on a Lifecycle now . . .
:,(
I had never biked since my $75 third-hand MTB that I used for commuting to work down Magazine Street in New Orleans got stolen eight years before.
Bought a used Jamis hybrid from the LBS to cruise around town with the wife. Thing weighs @28#.
At the gym, rode the Lifecycle before my first ever sprint tri. MPH had me at 23.3 for a good hour or so. I will CRUSH the competition.
*At the race, I rode the hybrid and got passed by multiple 13-year-olds and obese people *
Bet I could hit 34.5 MPH on a Lifecycle now . . .
:,(
Are you mocking me, or did you kill someone in prison?
I know, this is a lame excuse for a bike workout but I cannot get motivated to ride the trainer at home late at night. So to the gym I go at lunch.
You folks are super smart so I was curious if anyone has a formula to calculate the wattage on a Platinum Series Upright LifeCycle bike if the Level and RPM are known?
Let the pink comments commence!
Life Fitness bikes do a really good job of measuring watts and calorie expenditure rates accurately. The Navy has tested many and Life Fitness is one of the best. I found watts to be very accurate (tested with a Vacumed Ergometer Calibrator) and calorie expenditure has been verified by the Naval Health Research Center (the report can be found on the DTIC site, google it). Most of these bikes have a method of changing the display parameters. If you check the manual, you can probably set it up to display watts, even if this does not seem to be a default setting. I was able to do so on the life fitness bikes I tested.
Here is a little project I did on the Life Fitness 95 CI Classic:
Hi Mike:
Thank you so much for posting your report. I have a couple of questions if you don’t mind.
What was the displayed power on the console when the power driving the cranks was 100, 200, and 300? Surely it actually reports a number for watts? In our lab we have recently found gross over reporting (150% above actual) of power on one brand of commercial exercise bikes and plan to do a study with many brands and models.
If you wanted to determine the accuracy of the kcals burned why not just have some people pedal and measure expired gases with a metabolic cart?
Cheers,
Jim
Life Fitness bikes do a really good job of measuring watts and calorie expenditure rates accurately. The Navy has tested many and Life Fitness is one of the best. I found watts to be very accurate (tested with a Vacumed Ergometer Calibrator) and calorie expenditure has been verified by the Naval Health Research Center (the report can be found on the DTIC site, google it). Most of these bikes have a method of changing the display parameters. If you check the manual, you can probably set it up to display watts, even if this does not seem to be a default setting. I was able to do so on the life fitness bikes I tested.
Here is a little project I did on the Life Fitness 95 CI Classic:
Hi Mike:
Thank you so much for posting your report. I have a couple of questions if you don’t mind.
What was the displayed power on the console when the power driving the cranks was 100, 200, and 300? Surely it actually reports a number for watts? In our lab we have recently found gross over reporting (150% above actual) of power on one brand of commercial exercise bikes and plan to do a study with many brands and models.
If you wanted to determine the accuracy of the kcals burned why not just have some people pedal and measure expired gases with a metabolic cart?
Cheers,
Jim
Life Fitness bikes do a really good job of measuring watts and calorie expenditure rates accurately. The Navy has tested many and Life Fitness is one of the best. I found watts to be very accurate (tested with a Vacumed Ergometer Calibrator) and calorie expenditure has been verified by the Naval Health Research Center (the report can be found on the DTIC site, google it). Most of these bikes have a method of changing the display parameters. If you check the manual, you can probably set it up to display watts, even if this does not seem to be a default setting. I was able to do so on the life fitness bikes I tested.
Here is a little project I did on the Life Fitness 95 CI Classic:
http://www.dtic.mil/dtic/tr/fulltext/u2/a590106.pdf
Hi Jim
We previously measured the accuracy of the calorie counters on the bikes using a Parvomedics metabolic cart. The accuracy was very good on the Lifefitness 95 CI Classic. The Navy uses this bike for fitness testing, using a 12 minute max calorie burn to estimate aerobic fitness. That work was done at the Naval Health Research Center. Recently we looked at some other devices. That work is here: http://www.dtic.mil/docs/citations/ADA590107
The purpose of this project was to simply see how much variation there was from bike to bike, especially in well used bikes. The display mode that shows watts does not show calories, so we could not look at both at the same time. However, in taking a quick look at a few bikes, the wattage was very good, typically within 1-2 watts and these are bikes with thousands of hours of use. Lifefitness puts out a good product.
No, commiserating, because been there done that. Actually this morning, on my 7 mile run, I got passed by obese people, old ladies, toddlers, and Dick Cheney. Hell, I even got passed by a fuckin’ race-walker (although she did have a Team USA kit, so maybe that makes it better?..). Sleep deprivation and stress has been catching up to me, I guess.
So no, I didn’t mean to mock you. Although I will not confirm or deny killing anyone in prison, so you may or may not have to watch your back 
Thanks Mike. This paper will really help us as one of my students is planning a similar study in local gyms.
Can you tell me when this study was done? My interaction with the engineer of one brand of bikes told me that in the last ten years systematic overestimation of power and calories has been become standard practice. He said you couldn’t sell a bike that was accurate because the customer will buy the one that gives the most power or calories for a given perceived exertion. Your worst bike in that study is slightly more accurate than the brand we’ve tested.
Thanks again,
Jim
We previously measured the accuracy of the calorie counters on the bikes using a Parvomedics metabolic cart. The accuracy was very good on the Lifefitness 95 CI Classic. The Navy uses this bike for fitness testing, using a 12 minute max calorie burn to estimate aerobic fitness. That work was done at the Naval Health Research Center. Recently we looked at some other devices. That work is here: http://www.dtic.mil/.../citations/ADA590107
The purpose of this project was to simply see how much variation there was from bike to bike, especially in well used bikes. The display mode that shows watts does not show calories, so we could not look at both at the same time. However, in taking a quick look at a few bikes, the wattage was very good, typically within 1-2 watts and these are bikes with thousands of hours of use. Lifefitness puts out a good product.
Thanks Mike. This paper will really help us as one of my students is planning a similar study in local gyms.
Can you tell me when this study was done? My interaction with the engineer of one brand of bikes told me that in the last ten years systematic overestimation of power and calories has been become standard practice. He said you couldn’t sell a bike that was accurate because the customer will buy the one that gives the most power or calories for a given perceived exertion. Your worst bike in that study is slightly more accurate than the brand we’ve tested.
Thanks again,
Jim
We previously measured the accuracy of the calorie counters on the bikes using a Parvomedics metabolic cart. The accuracy was very good on the Lifefitness 95 CI Classic. The Navy uses this bike for fitness testing, using a 12 minute max calorie burn to estimate aerobic fitness. That work was done at the Naval Health Research Center. Recently we looked at some other devices. That work is here: http://www.dtic.mil/.../citations/ADA590107
The purpose of this project was to simply see how much variation there was from bike to bike, especially in well used bikes. The display mode that shows watts does not show calories, so we could not look at both at the same time. However, in taking a quick look at a few bikes, the wattage was very good, typically within 1-2 watts and these are bikes with thousands of hours of use. Lifefitness puts out a good product.
Hi Jim
Which study are you referring to? We did one of the projects this past summer (ergometer calibrator) and the other the previous summer (7 commercial devices). NHRC tested the calorie counter on the Life Fitness bike a few years back. I think somewhere around 2003 but I am not sure.
Thanks all for the interesting data and info!
As I created this post, I also sent Life Cycle an email. They were very quick to resond and their Customer Services and Sales team sent me a very helpful chart to show the different wattage readings at the various levels and RPM outputs.
If you are interested, send me an email at larrybradleytoronto at yahoo.ca
Thanks again,
Larry