FTP & Cadence
carytb
Posts: 14
Quick question I've just done a session on a Watt bike whilst connected up to an analyser via a face mask. It was for a guy doing an Msc. I found that my indicated FTP was about 250W as opposed to the 270 which I was expecting. Could the fact that a) I had this bloody mask strapped to my face and b) because his protocol for the particular thing he was looking at was set at a high resistance I was grinding away at 75rpm rather than my usual 90-95 rpm, have anything to do with it.
Thanks
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Comments
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Yes to both. Although if you were expecting a higher number, presumably you had done a similar test previously?0
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In addition to what Imposter said, there's a few percent that can be attributed between different power meters.Insta: ATEnduranceCoaching
ABCC Cycling Coach0 -
carytb wrote:I had this bloody mask strapped to my face
What is this? Is this one of those restrictive workout masks to simulate high elevation training?0 -
Presumably they were measuring expired gases as well (VO2max?)
What was the actual protocol and were you able to see your power numbers and HR as you did the test?0 -
Thats assuming the Wattbike's PO is correct.
Protocol dependent as well (typically 20/25 W/min) increments, or 5 W every 12's can slightly later end PO.
Bit of a low cadence that.
Assuming also the online system was calibrated correctly, if its cortex they can read way off if not calibrated correctly,.
And depends what they have classed FTP as, assuming he has either just taken the ventilatory thresholds, (GET) and (RCT) VT1 and VT2, but even eying those from visual plots takes some experiences, unless they have used some software to calculated it. Or given them as a % of peak 60's power?
are you just in the lab once? what was it for if you don't mind me asking?
What makes you think the 250 isn't correct?I do science, sometimes.0 -
burnthesheep wrote:carytb wrote:I had this bloody mask strapped to my face
What is this? Is this one of those restrictive workout masks to simulate high elevation training?
No it was just measuring the ratio of carb/fat burning, calories and an estimation of VO2max. The student was looking into the effect of peppermint on performance. I've got to do the same thing in a couple of weeks0 -
It was looking at the effect of peppermint on performance. I did 2 x 10K max efforts with 5 minutes rest. The ftp was my estimation from that, comparing it with what I am reasonably sure is my ftp from my stages power meter from a number of efforts I've done on my turbo. I do it again in 2 weeks as it is a blind test involving a placebo.mentalalex wrote:Thats assuming the Wattbike's PO is correct.
Protocol dependent as well (typically 20/25 W/min) increments, or 5 W every 12's can slightly later end PO.
Bit of a low cadence that.
Assuming also the online system was calibrated correctly, if its cortex they can read way off if not calibrated correctly,.
And depends what they have classed FTP as, assuming he has either just taken the ventilatory thresholds, (GET) and (RCT) VT1 and VT2, but even eying those from visual plots takes some experiences, unless they have used some software to calculated it. Or given them as a % of peak 60's power?
are you just in the lab once? what was it for if you don't mind me asking?
What makes you think the 250 isn't correct?0 -
Your thinking is that you're 270 is right and this test is wrong.
It is possible the 250 is correct and your estimate is wrong
Most likely outcome is BOTH are wrong.
You can only really compare FTP progress by using the same bike or meter in each test. There is no real guarantee The recorded power output is 100% accurate only that each time you do the test the changes are a accurate improvement or decline. There are no 2 meters o the market that are 100% identical in output recorded and some are not even accurate from one device to another exactly the same. All that really matters is that you can read the data and spot any changes. Other than that they are just numbers0 -
Since you know what the test is for, it's not exactly blind.carytb wrote:burnthesheep wrote:carytb wrote:I had this bloody mask strapped to my face
What is this? Is this one of those restrictive workout masks to simulate high elevation training?
No it was just measuring the ratio of carb/fat burning, calories and an estimation of VO2max. The student was looking into the effect of peppermint on performance. I've got to do the same thing in a couple of weeks
To establish a solid FTP estimate you need:
- accurate data,
- a suitable test protocol and
- appropriate testing conditions.
I've not read anything in the thread so far that suggested all three of those conditions have been met.
As to factors that can influence performance on the day, well there are a multitude of those.0 -
maryka wrote:Presumably they were measuring expired gases as well (VO2max?)
What was the actual protocol and were you able to see your power numbers and HR as you did the test?
The protocol was specific to his test and was a 1K flat out sprint, 5min rest then 2 x 10K fallout efforts with 5min rest in between. This will be repeated in 2 weeks. The Watt bike resistance was set at 10 which resulted in a cadence on my part for the main test of 75 rpm. I could see my HR, cadence and power numbers. He was measuring expired gases and the computer gave an estimation of VO2max ( which incidentally tallied almost exactly with what my Garmin 520 has given me)
Given it wasn't a ramp test the expired gases , unsurprisingly showed a very rapid ramp unto 100% carb0 -
carytb wrote:The protocol was specific to his test and was a 1K flat out sprint,
I would question this, as sprinting 'flat out' (ie maximal effort) for 1km is simply not feasible.0 -
Sounds like the peppermint had a negative effect on your performance, to the tune of 20 watts.
Seriously though, this is why FTP tests should always be undertaken with the same protocol, on the same equipment - as otherwise there are too many potential discrepancies between one power meter and another.
The surprise for me would be if the FTP came back exactly what you were expecting.0 -
Imposter wrote:carytb wrote:The protocol was specific to his test and was a 1K flat out sprint,
I would question this, as sprinting 'flat out' (ie maximal effort) for 1km is simply not feasible.
What he wanted me to do was go flat out then just hang on until the 1K was up. My power at the end of it was pretty abysmal!0 -
I don't know if I had the peppermint or the placebo and will only probably find out after the 2nd test in 2 weeksTimothyW wrote:Sounds like the peppermint had a negative effect on your performance, to the tune of 20 watts.
Seriously though, this is why FTP tests should always be undertaken with the same protocol, on the same equipment - as otherwise there are too many potential discrepancies between one power meter and another.
The surprise for me would be if the FTP came back exactly what you were expecting.0
