|   How are numbers on Lifecycles determined? | PC1
Mar 13, 2002 8:06 PM | | I have free access to a gym and on weeks where I don't get to ride much, I head to the gym and hop on a Lifecycle 9500. The display tells me that I've burned 590 calories at the end of my workout and I'm burning 419 per hour at the end. Since the computer doesn't require any input from the rider I wonder how these numbers are determined. Does the manufacturer arbitrarily figure the rider is in the 6'0", 160lbs. range and go from there? BTW I'm 5'8", 142lbs., 39 years old. I pedal for 45 minutes at level 8 (out of 12) in the random mode. I also keep my cadence 10 rpm's higher than the display suggests I should be at. Since the computer doesn't ask for age, weight or heigth, where do the numbers come from? This is a military gym and the staff on hand doesn't know much about these stationary (Mebbe ery)bikes. If anyone knows I'd love to read an explanation. Thanks in advance.
PC1 |
| Well... | MTBRchick
Mar 14, 2002 12:50 PM | | ...you're right about the fact that the machine is making generalizations to determine the number of calories you have burned during exercise. Even if the bike asks you to input your current weight (the bikes at my gym DO request that information) it would also need to know your body compostion and heart rate to accurately display "TOTAL CALORIES BURNED". Keep in mind that this number is used as a marketing tool. Think about it, if one machine told you that you were burning 500 kcal/hour and another told you you were burning 1000 kcal/hour, which would you want to use? I would also suggest using the MANUAL program on the stationary bike. You can still change the resistance, but I have found that the random program has such a wide range of resistance levels, that often times you are working BELOW your training heart rate zone. You have much more control over the intensity of your workout if you use MANUAL. |
| Not sure this is right... | kwm
Mar 15, 2002 8:03 AM | | A calorie is a measure of energy (the amount of energy it takes to heat 1 liter of water 1 degree C? Can't remember exactly.)
It seems to me that the amount of energy it takes to turn the pedals at a given resistance level (converted from watts) wouldn't be hard to determine.
Of course there would be variables, but the primary one would be biomechanical pedaling efficiency and not specific physiology. I imagine that when the engineers were writing the software, they'd just use some kind of average (or more likely, make no assumptions at all for inefficiencies.)
Your point about marketing is well taken, though. There may be some exaggeration going on and even if there isn't, the number is probably not that accurate. |
| Thanx for the input...PC1...nm | PC1
Mar 16, 2002 8:42 PM | | ; |
| yes this is correct | alFred
Mar 17, 2002 1:28 AM | | they can calculate power output and make some generic assumptions.
basically if you take your power output and multiply by 3.6 you'd get somewhere in ballpark.
I seriously doubt the power output is measured accurately, the error probably falls into +/-10% range, but the biggest gamble is the pedaling efficiency which depending on cycling background somewhere btw 20 to 25%. The efficiency also depends on effort you're much less efficient in anaerobic mode. Obviously number would be on high side since it is also a marketing tool, still error shouldn't exceed 30%.
I would just stick with one machine even if it lies, you mainly use # to compare different sessions and that would be far more accurate comparrison good luck |
| |
