Pretty simple question. I did a fifteen minute computrainer power test. I averaged 355 for the test. This test was mainly just to have something repeatable on a monthly basis, and we weren’t necessarily looking to find an FTP. But I am kind of interested in getting a decent range for an FTP. Tried to search but didn’t find anything for 15 minutes. I’m not sure how drastically different it would be than a 20 min. test. Thanks.
90%
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90%
Can you expand a bit on that? I’m curious as to how 75% of a test constitutes 90% of the final output. Not disagreeing, just would like to know the maths behind it, because maths is hard.
John
I don’t know the answer, but probably has something to do with a test comprising of 33% (i.e. 20’ power) representing approximatly ~105% of FTP (i.e. FTP = 0.95 * 20’ Pwr). It’s not a linear relationship. I’m sure the smart guys will note something about the slope of the critical power curve and AWC and a bunch of other stuff that I don’t know anything about. I would guess that if GP was being serious, then it’s likely an empirical relationship.
Or, I’m totally wrong, which will not be the first time today.
Your best bet is to do a shorter test and use the critical power model.
Better yet, would be to do say a 3 minute max effort and then do a 20 minute max effort a few days later, then put all three numbers into a CP model.
I’d say just a 3min will be enough. 20min is close enough to 15min that it won’t make that much of a difference.
so 2 point for the CP model to find FTP
FTP is just an estimation from a 20min test too. Just do like 91-94% of your 15min power and it’ll be close enough. You aren’t training based on it are you? So this is plenty accurate enough since you are just curious.
… But I am kind of interested in getting a decent range for an FTP.Then you should kind of do a proper test. Like, say, close to 60 minutes of effort.
Unless the purpose was to get “355” out there…
I do 30CPs for my FTP tests. I take a good 15 minutes or more, usually 20 ,to get my HR well into Z5. I’m normally spinning mid 90s for this part. Then I drop the resistance and up the spin rate to over 100 for about a minute, have something to drink and have a gel, then drop my rpm to about 80 for another 1-2 minutes as my HR drops a couple of zones - basically till I am breathing normally and I am “ready to go”. I think of something that really pisses me off and start my 30 minute session and HR is quickly (in less than a minute) into Z5.
Then it is curse and push as I see my HR slowly climb but I need to keep enough back to finish. At the half way mark, If I think I can finish, I start to go a bit harder, if at the half way mark I doubt that I can finish I know I’m going at max. At 5 to 8 minutes left you should feel like you can’t finish - if you were on the road you’d likely crash. The drool can no longer be contained and just flows, mixing with the snot. You could do laps in the pool of sweat under you and doing a hard swim set seems like a tropical vacation. As you continue down to 2 minutes your vision narrows, you’re past telling your legs to shut up - that takes coherent thought and you have none. The seconds, become minutes, you’ve never seen a timer move so slow, then you are down to 30 seconds and you realize you’ve done it and you get just enough adrenaline to finish and as you are gasping for breath an explicative explodes (something like “I killed you that time you MF”) at which time you hear your spouse ask the usual “did you say something dear.”
Hey, check out your max HR.
Unfortunately, I’ve got one of these coming up soon but not exactly looking forward to it. Sort of like going into a rough part of town - could be exciting or I may get a shit kicking.
My 15min power is the same as my 20min power but I’ve never done a 15m test. If I look at the CP curve predicted by Golden Cheetah it suggests the 15m power should be about 2% higher. If you believe 20m power is 95% of FTP then I would go with 92% for 15m power.
I did a fifteen minute computrainer power test.
Try doing a 20-minute test next time since it’s more commonly use to estimate your FTP. Five more minutes of pain is a cake walk.